Contents Section: Mechanical All sections

Engine System - General Information Ford Explorer Sport Trac II

Mechanical 6 illustrations ~8376 words

Material

ItemSpecificationFill Capacity
Dye-Lite® Gasoline Engine Oil Leak Detection Dye 164-R3700 (Rotunda)
LOCTITE® Retaining Compound 620 High Temperature Loctite 620/Permatex 62050WSK-N2G349-A9
Motorcraft SAE 5W-20 Premium Synthetic Blend Motor Oil XO-5W20-QSP (US); Motorcraft SAE 5W-20 Super Premium Motor Oil CXO-5W20-LSP12 (Canada); or equivalentWSS-M2C930-A
Motorcraft SAE 5W-30 Premium Synthetic Blend Motor Oil XO-5W30-QSP (US); Motorcraft SAE 5W-30 Super Premium Motor Oil CXO-5W30-LSP12 (Canada); or equivalentWSS-M2C929-A
Threadlock 262 TA-26WSK-M2G351-A6

Material

WARNINGDo not operate the engine with the hood open until the fan blade has been examined for possible cracks and separation. A damaged fan can separate during operation. Failure to follow this instruction may result in serious personal injury.

Note. When repairing engines, all parts must be contamination free. If contamination/foreign material is present when repairing an engine, premature engine failure may occur.

Note. This article contains information, steps and procedures that may not be specific to every engine.

Note. If a component fails to meet the specifications, repair or install a new component as necessary.

Note. Refer to the appropriate Engine Article for the specification.

This article covers general procedures and diagnosis and testing of the engine system, except for exhaust emission control devices, the diagnosis of which are covered in the Introduction - Gasoline Engines article.

The engine incorporates the following features

  1. a closed PCV system. For service, refer to «ENGINE EMISSION CONTROL»(/ford/explorer-sport-trac/ii-2006-2010/remont/auxiliary-emission-control-systems/#engine-emission-control) article.
  2. an exhaust emission control system. For service, refer to «ENGINE EMISSION CONTROL»(/ford/explorer-sport-trac/ii-2006-2010/remont/auxiliary-emission-control-systems/#engine-emission-control) article.
  3. an Evaporative Emission (EVAP) control system. For service, refer to «EVAPORATIVE EMISSIONS»(/ford/explorer-sport-trac/ii-2006-2010/remont/auxiliary-emission-control-systems/#evaporative-emissions-control-system) article.

Some engines incorporate a fail-safe cooling system. Refer to the appropriate Engine article for the procedure.

The engine, fuel system, ignition system, emissions system and exhaust system all affect exhaust emission levels and must be maintained according to the maintenance schedule. Refer to the scheduled Maintenance Guide.

Correct engine identification is required to order parts. Refer to the appropriate Engine article for the procedure.

For complete vehicle and engine identification codes, refer to IDENTIFICATION CODES article.

Special Tools Illustration Tool Name Tool Number 12-Volt Master UV Diagnostic Inspection Kit 164-R0756 or equivalent (Leak Detector) Commercially Available Hydraulic Lash Adjuster Leakdown Tester - Dial Indicator Gauge Adapter 303-007 (TOOL-6565-AB) or equivalent Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent Engine Cylinder Leak Detection/Air Pressurization Kit 014-00708 or equivalent EngineEAR 107-R2100 or equivalent EngineEAR/ChassisEAR 107-R2102 or equivalent Oil Pressure Gauge 303-088 (T73L-6600-A) Quick Disconnect Compression Tester 134-R0212 or equivalent UV Leak Detector Kit 164-R0756 or equivalent Vacuum/Pressure Tester 164-R0253 or equivalent

Scheme 1

Scheme 1: Engine

Scheme 2

Scheme 2

Scheme 3

Scheme 3
ItemSpecification
Dye-Lite® Gasoline Engine Oil Leak Detection Dye 164-R3700 (Rotunda)
Motorcraft SAE 5W-20 Premium Synthetic Blend Motor Oil XO-5W20-QSP (US); Motorcraft SAE 5W-20 Super Premium Motor Oil CXO-5W20-LSP12 (Canada); or equivalentWSS-M2C930-A
Motorcraft SAE 5W-30 Premium Synthetic Blend Motor Oil XO-5W30-QSP (US); Motorcraft SAE 5W-30 Super Premium Motor Oil CXO-5W30-LSP12 (Canada); or equivalentWSS-M2C929-A

Material

There are 2 diagnostic paths that can be followed depending on the type of engine concern. Carry out either the Inspection and Verification - Engine Performance or Inspection and Verification - NVH.

Inspection and Verification - Engine Performance

  1. Verify the customer concern by operating the engine to duplicate the condition.
  2. Visually inspect for obvious signs of mechanical damage. Refer to the following chart. VISUAL INSPECTION CHART Mechanical Engine coolant leaks Engine oil leaks Fuel leaks Damaged or severely worn parts Loose mounting bolts, studs and nuts
  3. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
  4. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
  5. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article, No Power To The Scan Tool, to diagnose no power to the scan tool.
  6. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. verify the scan tool operation with a known good vehicle. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article to diagnose no response from the PCM.
  7. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article. If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
  8. Clear the CMDTCs and carry out the self-test diagnostics for the PCM.
  9. If the DTCs retrieved are related to the concern, refer to «MULTIFUNCTION ELECTRONIC MODULES»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#multifunction-electronic-modules) article.
  10. If no DTCs related to the concern are retrieved, go to «Symptom Chart - Engine Performance»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-system-general-information) .

Inspection and Verification - NVH

  1. NVH symptoms should be identified using the diagnostic tools and techniques that are available. For a list of these techniques, tools, an explanation of their uses and a glossary of common terms, refer to «NOISE, VIBRATION AND HARSHNESS»(/ford/explorer-sport-trac/ii-2006-2010/remont/oem-general-information/#noise-vibration-and-harshness) article.
  2. Verify the customer concern by operating the engine to duplicate the condition.
  3. Check the engine oil level and check the oil for contamination. Low engine oil level or contaminated oil are a common cause of engine noise. If the oil is contaminated, the source of the contamination must be identified and repaired as necessary.
  4. Visually inspect for obvious signs of mechanical damage. Refer to the following chart. VISUAL INSPECTION CHART Mechanical Loose mounting bolts, studs and nuts Damaged or leaking powertrain mounts Damaged or disconnected vacuum hoses Obstruction of cooling fan Obstruction of Front End Accessory Drive (FEAD) Obstruction of Rear End Accessory Drive (READ), if equipped. Damaged or disconnected air intake components
  5. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
  6. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
  7. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article, No Power To The Scan Tool, to diagnose no power to the scan tool.
  8. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. verify the scan tool operation with a known good vehicle. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article to diagnose no response from the PCM.
  9. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#module-communications-network) article. If the network test passes, retrieve and record CMDTCs.
  10. Clear the CMDTCs and carry out the self-test diagnostics for the PCM.
  11. If the DTCs retrieved are related to the concern, refer to «MULTIFUNCTION ELECTRONIC MODULES»(/ford/explorer-sport-trac/ii-2006-2010/remont/communication-devices/#multifunction-electronic-modules) article.
  12. If no DTCs related to the concern are retrieved, continue the inspection and verification if a noise concern is related to the engine. For vibration concerns and noise concerns such as powertrain mounts, air intake system and starter Go to «Symptom Chart - NVH»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-system-general-information) . In some cases, a noise may be a normal characteristic of that engine type. In other cases the noise may require further investigation. Comparing the noise to a similar year/model vehicle equipped with the same engine will aid in determining if the noise is normal or abnormal. Once a customer concern has been identified as an abnormal engine noise, it is critical to determine the location of the specific noise. Use the EngineEAR/ChassisEAR or stethoscope (the noise will always be louder closer to the noise source) to isolate the location of the noise to one of the following areas. Fuel injector(s) Upper end of engine Lower end of engine Front of engine Rear of engine Fuel injector noise - A common source of an engine ticking noise can be related to the fuel injector(s). This is normal engine noise that can be verified by listening to another vehicle. If the injector noise is excessive or irregular, use the EngineEAR/ChassisEAR or stethoscope to isolate the noise to a specific fuel injector. Upper end engine noise - A common source of upper end engine noise (ticking, knocking or rattle) includes the camshaft(s) and valve train. Upper end engine noise can be determined using the EngineEAR/ChassisEAR or stethoscope on the valve cover bolts. If the noise is loudest from the valve cover bolts, then the noise is upper end. The EngineEAR/ChassisEAR or stethoscope can be used to further isolate the noise to the specific cylinder bank and cylinder. Removal of the valve covers will be required to pinpoint the source of the noise. Lower end engine noise - A common source of lower end engine noise (ticking or knocking) includes the crankshaft, connecting rod(s) and bearings. Lower end noises can be determined by using the oil pan or cylinder block lug bosses. If the noise is loudest from these areas, then the noise is lower end. If an engine noise is isolated to the lower end, some disassembly of the engine may be required to inspect for damage or wear. Front of engine noise - A common source of noise from the front of the engine (squeal, chirp, whine or hoot) is the Front End Accessory Drive (FEAD) components. To isolate FEAD noise, carry out the Engine Accessory Test. Refer to «NOISE, VIBRATION AND HARSHNESS»(/ford/explorer-sport-trac/ii-2006-2010/remont/oem-general-information/#noise-vibration-and-harshness) article. Some other noises from the front of the engine (ticking, tapping or rattle) may be internal to the engine. Use the EngineEAR/ChassisEAR or stethoscope on the engine front cover to determine if the noise is internal to the engine. Removal of the engine front cover may be necessary to inspect internal engine components. Rear of engine noise - A common source of noise from the rear of the engine (knocking) is the flywheel/flexplate. Inspection of the flywheel/flexplate will be necessary.
  13. After the noise is localized, note the characteristics of the noise, including type of noise, frequency and conditions when the noise occurs and Go to «Symptom Chart - NVH»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-system-general-information) .

Symptom Chart - Engine Performance

ConditionPossible SourcesAction
Difficult startingDamaged ignition system Damaged fuel system Damaged starting systemRefer to the appropriate Engine article for the procedure. REFER to the Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware or equivalent scan tool.
Damaged charging system/batteryREFER to CHARGING SYSTEM - GENERAL INFORMATION article.
Burnt valveINSTALL a new valve.
Worn pistonFor 4.0L engines, INSTALL a new piston and connecting rod assembly. For 4.6L engines, INSTALL a new piston.
Worn piston ringsINSTALL new piston rings.
Worn cylinderREPAIR or INSTALL a new cylinder block.
Damaged head gasketINSTALL a new head gasket.
Damaged cooling systemRefer to the appropriate Engine article for the procedure. REFER to the VCM and IDS software with appropriate hardware, or equivalent scan tool.
Poor idlingVacuum leaks Malfunctioning or damaged ignition system Malfunctioning or damaged fuel systemRefer to the appropriate Engine article for the procedure. REFER to the Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool.
Damaged valve tappet or lash adjusterINSTALL a new valve tappet or lash adjuster.
Damaged valve tappet guide or valve tappetINSTALL a new valve tappet guide or valve tappet.
Incorrect valve-to-valve seat contactREPAIR or INSTALL a new valve or valve seat.
Damaged head gasketINSTALL a new head gasket.
Worn or damaged engine support bracketsINSTALL a new engine support brackets.
Worn or damaged engine support insulatorsINSTALL a new engine support insulator.
Worn or damaged transmission insulator and retainerINSTALL a new transmission insulator and retainer.
Abnormal combustionMalfunctioning or damaged fuel system Malfunctioning or damaged ignition system Malfunctioning or damaged air intake systemRefer to the appropriate Engine article for the procedure. REFER to the Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool.
Damaged valve tappet or lash adjusterINSTALL a new valve tappet or lash adjuster.
Damaged valve tappet guide or valve tappetINSTALL a new valve tappet guide or valve tappet.
Burnt or sticking valveREPAIR or INSTALL a new valve.
Weak or broken valve springINSTALL a new valve spring.
Carbon accumulation in combustion chamberELIMINATE carbon buildup.
Excessive oil consumptionLeaking oilREPAIR oil leakage.
Malfunctioning PCV systemREPAIR or INSTALL new necessary components.
Worn valve stem sealINSTALL a new valve stem seal.
Worn valve stem or valve guideINSTALL a new valve and valve guide.
Sticking piston ringsFor 4.0L engines, INSTALL a new piston and connecting rod assembly. For 4.6L engine, REPAIR or INSTALL new piston rings.
Worn piston ring grooveFor 4.0L engine, INSTALL a new piston and connecting rod assembly. For 4.6L engine, INSTALL a new piston and piston pin.
Worn piston or cylinderREPAIR or INSTALL a new piston or cylinder block.
Engine noiseLeaking exhaust systemREPAIR exhaust leakage.
Incorrect drive belt tensionREFER to ACCESSORY DRIVE article.
Malfunctioning generator bearingRefer to the appropriate Battery and Charging System article for the procedure.
Malfunctioning water pump bearingREFER to ENGINE COOLING article.
Malfunctioning or damaged cooling systemREFER to ENGINE COOLING article.
Malfunctioning or damaged fuel systemRefer to the appropriate Engine article for the procedure. REFER to the Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool.
Loose timing chain/beltADJUST or INSTALL a new timing chain/belt.
Damaged timing chain tensionerINSTALL a new timing chain tensioner.
Excessive main bearing clearanceNOTE: Remove the cylinder heads before removing the crankshaft. Failure to do so may result in engine damage. INSTALL a new crankshaft main bearing.
Seized or heat-damaged crankshaft main bearingINSTALL a new crankshaft main bearing.
Excessive crankshaft end playINSTALL a new thrust bearing or crankshaft.
Excessive connecting rod bearing clearanceINSTALL a new connecting rod bearing or connecting rod.
Heat damaged connecting rod bearingINSTALL a new connecting rod bearing.
Damaged connecting rod bushingFor 4.0L engine, INSTALL a new piston and connecting rod assembly. For 4.6L engine, INSTALL a new connecting rod bushing.
Worn cylinderREPAIR or INSTALL a new cylinder block.
Worn piston or piston pinFor 4.0L engine, INSTALL a new piston and connecting rod assembly. For 4.6L engine, INSTALL a new piston or piston pin.
Damaged piston ringsINSTALL new piston rings.
Bent connecting rodFor 4.0L engine, INSTALL a new piston and connecting rod assembly. For 4.6L engine, INSTALL a new connecting rod.
Malfunctioning valve tappet or lash adjusterINSTALL a new valve tappet or lash adjuster.
Excessive valve tappet or lash adjuster clearanceADJUST clearance or INSTALL a new valve tappet guide or valve tappet.
Broken valve springINSTALL a new valve spring.
Excessive valve guide clearanceADJUST clearance or INSTALL a new valve guide or valve.
Insufficient powerMalfunctioning or damaged ignition system Malfunctioning or damaged fuel system Malfunctioning or damaged air intake systemRefer to the appropriate Engine article for the procedure. REFER to the Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool.
Damaged or plugged exhaust systemINSPECT exhaust system.
Incorrect tire sizeREFER to SUSPENSION SYSTEM - GENERAL INFORMATION article.
Dragging brakesREFER to BRAKE SYSTEM - GENERAL INFORMATION article.
Slipping transmissionRefer to the appropriate Automatic Transmission article for the procedure.
Malfunctioning valve tappet or lash adjusterINSTALL a new valve tappet or lash adjuster.
Damaged valve tappet guide or valve tappetFor 4.0L engines, INSTALL a new cylinder head. For 4.6L engines, INSTALL a new valve tappet guide or valve tappet.
Compression leakage at valve seatFor 4.0L engines, INSTALL a new cylinder head. For 4.6L engines, REPAIR or INSTALL a new valve, valve seat or cylinder head.
Seized valve stemFor 4.0L engines, INSTALL a new cylinder head. For 4.6L engines, INSTALL a new valve.
Weak or broken valve springINSTALL a new valve spring.
Worn or damaged camshaftFor 4.0L engines, INSTALL a new cylinder head. For 4.6L engines, INSTALL a new camshaft.
Damaged head gasketINSTALL a new head gasket.
Cracked or distorted cylinder headINSTALL a new cylinder head.
Damaged, worn or sticking piston ring(s)REPAIR or INSTALL a new piston ring(s).
Worn or damaged pistonFor 4.0L engines, INSTALL a new piston and connecting rod assembly. For 4.6L engines, INSTALL a new piston and piston pin.
Oil in coolantLeaking head gasketINSTALL a new head gasket. Refer to the appropriate Engine article for the procedure.
Leaking oil coolerINSTALL a new oil cooler. Refer to the appropriate Engine article for the procedure.
Leaking oil filter adapterINSTALL a new oil filter adapter. Refer to the appropriate Engine article for the procedure.
Damaged cylinder headINSPECT the engine components for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure.
Damaged cylinder blockINSPECT the engine components for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure.
Coolant in oilLeaking head gasket Leaking oil cooler Leaking oil filter adapter Damaged cylinder head Damaged cylinder blockINSPECT the engine components for damage. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure.
NOTE
Remove the cylinder heads before removing the crankshaft. Failure to do so may result in engine damage.

Symptom Chart - Engine Performance

Symptom Chart - NVH

Note. NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to NOISE, VIBRATION AND HARSHNESS article. Since it is possible that any one of multiple systems may be the cause of the symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION AND HARSHNESS article for the next likely system and continue diagnosis.

ConditionPossible SourcesAction
Drone type noisePowertrain mount(s)CARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure.
Drumming noise - occurs inside the vehicle during idle or high idle, hot or cold. Very low-frequency drumming is very RPM dependentEngine vibration excites the body resonances inducing interior noiseCARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure.
Engine drumming noise - accompanied by vibrationPowertrain mount(s)CARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure.
Rattle - occurs at idle or at light acceleration from a stopPowertrain mount(s)CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, Refer to the appropriate Engine article for the procedure. For automatic transmission, Refer to the appropriate Automatic Transmission article for the procedure.
Whine/moan type noise - pitch increases or changes with vehicle speedPowertrain mount(s)CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, Refer to the appropriate Engine article for the procedure. For automatic transmission, Refer to the appropriate Automatic Transmission article for the procedure.
Clunk - occurs when shifting from PARK or between REVERSE and DRIVEPowertrain mountsCHECK the powertrain/drivetrain mounts for damage. INSTALL new mounts as necessary. For engine, Refer to the appropriate Engine article for the procedure. For automatic transmission, Refer to the appropriate Automatic Transmission article for the procedure.
Idle speed is too highCHECK for the correct idle speed.
Accessory drive bearing hoot - occurs at idle or high idle in cold temperatures of approximately +4°C (+40°F) or colder at the first start of the dayAccessory drive idler or tensioner pulley bearing is experiencing stick/slip between ball bearings and the bearing raceCARRY OUT the engine cold soak procedure. REFER to NOISE, VIBRATION AND HARSHNESS article. PLACE the EngineEAR probe directly on the idler/tensioner center post or bolt to verify which bearing is making the noise. INSTALL new parts as necessary. Refer to the appropriate Engine article for the procedure.
Accessory drive belt noise, squeal or chirpingDefective/worn or incorrect accessory drive belt Misaligned pulley(s) Pulley runout Damaged or worn accessory drive component or idler Fluid contamination of the accessory drive belt or pulleys Damaged or worn accessory drive belt tensioner Damaged pulley groovesCARRY OUT the Engine Accessory Test. REFER to NOISE, VIBRATION AND HARSHNESS article. INSPECT components and INSTALL new parts as necessary. REFER to ACCESSORY DRIVE article.
Clunking noiseCoolant pump has excessive end play or imbalanceCHECK the coolant pump for excessive end play. INSPECT the coolant pump for imbalance with the drive belt off. INSTALL a new coolant pump as necessary. REFER to ENGINE COOLING article.
Whine or moaning noiseAir intake systemCHECK the air cleaner and ducts for correct fit. INSPECT the air intake system for leaks or damage. REPAIR as necessary.
Whistling noise - normally accompanied with poor idle conditionAir intake systemCHECK the air intake ducts, Air Cleaner (ACL), Throttle Body (TB) and vacuum hoses for leaks and correct fit. REPAIR or ADJUST as necessary.
Hissing noise - occurs during idle or high idle that is apparent with the hood openVacuum leak noiseUSE the Ultrasonic Leak Detector/EngineEAR to locate the source. SCAN the air intake system from the inlet to each cylinder intake port. DISCARD the leaking parts and INSTALL a new component.
Vehicles with a plastic intake manifoldAcceptable condition. Some plastic manifolds exhibit this noise, which is the effect of the plastic manifold.
Grinding noise - occurs during engine crankingIncorrect starter motor mountingINSPECT the starter motor for correct mounting. REPAIR as necessary. Refer to the appropriate Engine article for the procedure.
Starter motorCHECK the starter motor. INSTALL a new starter motor as necessary. Refer to the appropriate Engine article for the procedure.
Incorrect starter motor drive engagementINSPECT the starter motor drive for wear or damage. INSTALL a new starter motor as necessary. Refer to the appropriate Engine article for the procedure. INSPECT the flywheel/flexplate for wear or damage. INSTALL a new flywheel/flexplate as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, front of engine - knocking noise from lower front of engineDamaged or separated crankshaft pulley/damperCHECK for obvious signs of damage or wobble during operation. INSTALL new as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, front of engine - ticking, tapping or rattling noise from the front of the engineTiming drive componentsREMOVE the accessory drive belt. Refer to the appropriate Engine article for the procedure. USE the EngineEAR to isolate the noise to the engine front cover. REMOVE the engine front cover and INSPECT the timing drive components. INSTALL new parts as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, upper end - ticking noise near the fuel rail and intake manifoldFuel rail clipCHECK for loose or damaged fuel rail clip(s). REPAIR as necessary.
Fuel injectorUSE the EngineEAR to isolate the noisy injector(s). INSTALL new injector(s) as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, upper end - ticking, knocking or rattle noise that occurs during idle or high idle during the first cold start of the day and may disappear as the engine warmsValve train noise (bled down lifter/lash adjuster)CARRY OUT the Valve Train Analysis Component Test in this article. INSTALL new parts as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, upper end - occurs mostly with a warm engine at light/medium accelerationWorn or damaged spark plugsREMOVE the spark plugs. INSPECT and INSTALL new as necessary. Refer to the appropriate Engine article for the procedure.
Carbon accumulation in combustion chamberBore scope the cylinder. ELIMINATE carbon buildup.
Engine noise, upper end - rattling noise from the valve train. Worse when the engine is coldLow oil levelCHECK the oil level. FILL as necessary.
Thin or diluted oilINSPECT the oil for contamination. If the oil is contaminated, CHECK for the source. REPAIR as necessary. CHANGE the oil and filter.
Low oil pressureCARRY OUT an oil pressure test. If not within specifications, REMOVE the engine oil pan. Refer to the appropriate Engine article for the procedure. INSPECT for a blocked oil pick up tube.
Worn valve train componentsCARRY OUT the Valve Train Analysis Component Test in this article. INSTALL new parts as necessary. Refer to the appropriate Engine article for the procedure.
Worn valve guidesCARRY OUT the Valve Guide Inner Diameter procedure.
Excessive runout of the valve seats on the valve faceCARRY OUT the Valve Seat Inspection procedure.
Engine noise, upper end - pinging noiseGasoline octane too lowVERIFY with customer the type of gasoline used. CORRECT as necessary.
Knock Sensor (KS) operationCHECK the KS. INSTALL a new KS as necessary. Refer to the appropriate Engine article for the procedure.
Incorrect spark timingREFER to the Introduction - Gasoline Engines article.
High operating temperatureINSPECT the cooling system for leaks. CHECK the coolant level. REFILL as necessary. CHECK the coolant for the correct mix ratio. DRAIN and REFILL as needed. VERIFY the engine operating temperature is within specifications. REPAIR as necessary.
Spark plugCHECK the spark plugs. REPAIR or INSTALL new spark plugs as necessary.
Catalytic converterAcceptable noise.
Engine noise, lower end - ticking or knocking noise near the oil filter adapterOil pumpUSE the EngineEAR to verify the oil pump as the source of the noise at low RPM. REPAIR as necessary. Refer to the appropriate Engine article for the procedure.
Engine noise, lower end - light knocking noise, also described as piston slap. Noise is most noticeable when the engine is cold with light to medium acceleration. The noise disappears as the engine warmsExcessive clearance between the piston and the cylinder wallCARRY OUT the Piston To Cylinder Bore Clearance procedure.
Engine noise, lower end - light double knock or sharp rap sound. Occurs mostly with a warm engine at idle or low speeds in drive. Increases in relation to engine load. Associated with a poor lubrication historyExcessive clearance between the piston and the piston pinVERIFY the piston pin bore diameter and the piston pin diameter are within specification. REFER to Piston Pin Bore Diameter and Piston Pin Diameter .
Excessive clearance between the piston and the connecting rodCARRY OUT the Connecting Rod-to-Piston Clearance procedure.
Engine noise, lower end - light knocking noise. The noise is most noticeable when the engine is warm. The noise tends to decrease when the vehicle is coasting or in NEUTRALExcessive clearance between the connecting rod bearings and the crankshaftCARRY OUT the Connecting Rod Bearing Journal-to-Bearing Clearance procedure.
Engine noise, lower end - deep knocking noise. The noise is most noticeable when the engine is warm, at lower RPM and under a light load and then at floatWorn or damaged crankshaft main bearingsCARRY OUT the Crankshaft Main Bearing Journal-to-Bearing Clearance procedure.
Engine noise, rear of engine - knocking noise at rear of engineDamaged flywheel/flexplateCARRY OUT the Flexplate Inspection procedure.
Engine vibration - vibration felt at all timesExcessive crankshaft pulley runoutCARRY OUT the Engine Accessory Test. INSTALL a new crankshaft pulley as necessary. Refer to the appropriate Engine article for the procedure.
Damaged or worn accessory componentCARRY OUT the Engine Accessory Test. REPAIR or INSTALL a new component as necessary.
Engine vibration - at idle, a low-frequency vibration (5-20 Hz) or mild shake that is felt through the seat/floorpanCylinder misfireUsing the scan tool, CARRY OUT the cylinder power balance and the relative compression test. REPAIR as necessary. Refer to the appropriate Engine article for the procedure.
Engine or torque converter out of balanceVERIFY the torque converter-to-crankshaft pilot clearance is correct. REPAIR as necessary. RE-INDEX the torque converter on the flex plate by 120 degrees for a 3-bolt converter or 180 degrees for a 4-bolt converter. Refer to the appropriate Automatic Transmission article for the procedure.
Engine vibration - is felt with increases and decreases in engine RPMPowertrain mount(s)CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, Refer to the appropriate Engine article for the procedure. For automatic transmission, Refer to the appropriate Automatic Transmission article for the procedure.
Engine or transmission grounded to chassisINSPECT the powertrain/drivetrain for correct clearances. REPAIR as necessary.
Engine vibration - increases intensity as the engine RPM is increasedEngine out-of-balanceCARRY OUT the Neutral Engine Run-Up (NERU) Test. REFER to NOISE, VIBRATION AND HARSHNESS article. ROTATE the torque converter, 120 degrees for 3-bolt or 180 degrees for 4-bolt. INSPECT the torque converter pilot outer diameter to crankshaft pilot inner diameter. REPAIR as necessary. Refer to the appropriate Automatic Transmission article for the procedure.
Engine vibration - mostly at coast/neutral coast. Condition improves with vehicle accelerationCombustion instabilityCHECK the ignition system. INSTALL new components as necessary. Refer to the appropriate Engine article for the procedure.
Engine vibration or shudder - occurs with light to medium acceleration above 56 km/h (35 mph)Worn or damaged spark plugsINSPECT the spark plugs for cracks, high resistance or broken insulators. INSTALL a new spark plug(s) as necessary. Refer to the appropriate Engine article for the procedure.
Plugged fuel injectorREPAIR or INSTALL a new injector as necessary. Refer to the appropriate Engine article for the procedure.
Contaminated fuelINSPECT the fuel for contamination. DRAIN the fuel system and refill.

Symptom Chart - NVH

Component Tests

The following component tests are used to diagnose engine concerns.

Engine Oil Leaks

Note. If an overnight drive is done, the fan air or road air blast can cause erroneous readings.

Note. When diagnosing engine oil leaks, the source and location of the leak must be positively identified prior to repair.

Prior to carrying out this procedure, clean all sealing surface areas with a suitable solvent to remove all traces of oil.

Engine Oil Leaks - Fluorescent Oil Additive Method

Use the UV Leak Detector Kit to carry out the following procedure for oil leak diagnosis.

  1. Add 29.6 ml (1 oz) of fluorescent additive to a minimum of 0.473L (1/2 qt) and a maximum of 0.946L (1 qt) engine oil and fill through the engine oil fill. If the oil is not premixed, the fluorescent additive will not have enough time to reach the crankcase, oil galleries and seal surfaces during this particular 15 minute test. The additive must be mixed with oil and added through the oil fill. Check the level on the oil level indicator to determine what amount of oil to premix. If it is in the middle of the crosshatch area or below the full mark, use 0.946L (1 qt), if it is at the full mark, use 0.473L (1/2 qt).
  2. Run the engine for 15 minutes. Stop the engine and inspect all seal and gasket areas for leaks using the UV Leak Detector Kit. A clear bright yellow or orange area will identify the leak. For extremely small leaks, several hours may be required for the leak to appear.
  3. At the end of the test, make sure the oil level is within the upper and lower oil indicator marks. Remove oil as necessary if it registers above the full mark.

Leakage Points - Underhood

Examine the following areas for oil leakage

  1. Valve cover gaskets
  2. Intake manifold gaskets
  3. Cylinder head gaskets
  4. Oil bypass filter
  5. Oil filter adapter
  6. Engine front cover
  7. Oil filter adapter and filter body
  8. Oil level indicator tube connection
  9. Oil pressure sensor

Leakage Points - Under Engine - With Vehicle on Hoist

Examine the following areas for oil leakage

  1. Oil pan gaskets
  2. Oil pan sealer
  3. Oil pan rear seal
  4. Engine front cover gasket
  5. Crankshaft front seal
  6. Crankshaft rear oil seal
  7. Crankshaft main bearing cap side bolts
  8. Oil filter adapter and filter body
  9. Oil cooler, if equipped

Leakage Points - With Transmission and Flywheel Removed

Examine the following areas for oil leakage

  1. Crankshaft rear oil seal
  2. Rear main bearing cap parting line
  3. Rear main bearing cap and seals
  4. Flywheel mounting bolt holes (with flywheel installed)
  5. Camshaft rear bearing covers or pipe plugs at the end of oil passages

Oil leaks at crimped seams in sheet metal parts and cracks in cast or stamped parts can be detected when using the dye method.

Compression Test - Compression Gauge Check

  1. Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs.
  2. Set the throttle plates in the wide-open position.
  3. Install a compression gauge, such as the Quick Disconnect Compression Tester, in the No. 1 cylinder.
  4. Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of 5 compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
  5. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.

Compression Test - Test Results

The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75% of the highest reading. Refer to the Compression Pressure Limit Chart.

Maximum PressureMinimum PressureMaximum PressureMinimum PressureMaximum PressureMinimum PressureMaximum PressureMinimum Pressure
924 kPa (134 psi)696 kPa (101 psi)1,131 kPa (164 psi)848 kPa (123 psi)1,338 kPa (194 psi)1,000 kPa (146 psi)1,544 kPa (224 psi)1,158 kPa (168 psi)
938 kPa (136 psi)703 kPa (102 psi)1,145 kPa (166 psi)855 kPa (124 psi)1,351 kPa (196 psi)1,014 kPa (147 psi)1,558 kPa (226 psi)1,165 kPa (169 psi)
952 kPa (138 psi)717 kPa (104 psi)1,158 kPa (168 psi)869 kPa (126 psi)1,365 kPa (198 psi)1,020 kPa (148 psi)1,572 kPa (228 psi)1,179 kPa (171 psi)
965 kPa (140 psi)724 kPa (106 psi)1,172 kPa (170 psi)876 kPa (127 psi)1,379 kPa (200 psi)1,034 kPa (150 psi)1,586 kPa (230 psi)1,186 kPa (172 psi)
979 kPa (142 psi)738 kPa (107 psi)1,186 kPa (172 psi)889 kPa (129 psi)1,303 kPa (202 psi)1,041 kPa (151 psi)1,600 kPa (232 psi)1,200 kPa (174 psi)
933 kPa (144 psi)745 kPa (109 psi)1,200 kPa (174 psi)903 kPa (131 psi)1,407 kPa (204 psi)1,055 kPa (153 psi)1,055 kPa (153 psi)1,207 kPa (175 psi)
1,007 kPa (146 psi)758 kPa (110 psi)1,214 kPa (176 psi)910 kPa (132 psi)1,420 kPa (206 psi)1,062 kPa (154 psi)1,627 kPa (154 psi)1,220 kPa (177 psi)
1,020 kPa (148 psi)765 kPa (111 psi)1,227 kPa (178 psi)917 kPa (133 psi)1,434 kPa (208 psi)1,075 kPa (156 psi)1,641 kPa (238 psi)1,227 kPa (178 psi)
1,034 kPa (150 psi)779 kPa (113 psi)1,241 kPa (180 psi)931 kPa (135 psi)1,448 kPa (210 psi)1,083 kPa (157 psi)1,655 kPa (240 psi)1,241 kPa (180 psi)
1,048 kPa (152 psi)786 kPa (114 psi)1,255 kPa (182 psi)936 kPa (136 psi)1,462 kPa (212 psi)1,089 kPa (158 psi)1,669 kPa (242 psi)1,248 kPa (181 psi)
1,062 kPa (154 psi)793 kPa (115 psi)1,269 kPa (184 psi)952 kPa (138 psi)1,476 kPa (214 psi)1,103 kPa (160 psi)1,682 kPa (244 psi)1,262 kPa (183 psi)
1,076 kPa (156 psi)807 kPa (117 psi)1,282 kPa (186 psi)965 kPa (140 psi)1,489 kPa (216 psi)1,117 kPa (162 psi)1,696 kPa (246 psi)1,269 kPa (184 psi)
1,089 kPa (158 psi)814 kPa (118 psi)1,296 kPa (188 psi)972 kPa (141 psi)1,503 kPa (218 psi)1,124 kPa (163 psi)1,710 kPa (248 psi)1,202 kPa (186 psi)
1,103 kPa (160 psi)827 kPa (120 psi)1,310 kPa (190 psi)979 kPa (142 psi)1,517 kPa (220 psi)1,138 kPa (165 psi)1,724 kPa (250 psi)1,289 kPa (187 psi)
1,110 kPa (161 psi)834 kPa (121 psi)1,324 kPa (192 psi)993 kPa (144 psi)1,631 kPa (222 psi)1,145 kPa (166 psi)

COMPRESSION PRESSURE LIMIT CHART

If one or more cylinders read low, squirt approximately one tablespoon of engine oil on top of the pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.

Compression Test - Interpreting Compression Readings

  1. If compression improves considerably, piston rings are faulty.
  2. If compression does not improve, valves are sticking or seating incorrectly.
  3. If 2 adjacent cylinders indicate low compression pressures and squirting oil on each piston does not increase compression, the head gasket may be leaking between cylinders. Engine oil or coolant in cylinders could result from this condition. Use the Compression Pressure Limit Chart when checking cylinder compression so that the lowest reading is at least 75% of the highest reading.

Cylinder Leakage Detection

When a cylinder produces a low reading during the compression test, use of the Engine Cylinder Leak Detection/Air Pressurization Kit will be helpful in pinpointing the exact cause.

The leakage detector is inserted in the spark plug hole, the piston is brought up to dead center on the compression stroke and compressed air is admitted.

Once the combustion chamber is pressurized, a special gauge included in the kit will read the percentage of leakage. Leakage exceeding 20% is excessive.

While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak at the intake valve will be heard in the Throttle Body (TB). A leak at the exhaust valve can be heard at the tail pipe. Leakage past the piston rings will be audible at the PCV connection. If air is passing through a blown head gasket to an adjacent cylinder, the noise will be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder block or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator.

Excessive Engine Oil Consumption

Nearly all engines consume oil, which is essential for normal lubrication of the cylinder bore walls and pistons and rings. Determining the level of oil consumption may require testing by recording how much oil is being added over a given set of miles.

Customer driving habits greatly influence oil consumption. Mileage accumulated during towing or heavy loading generates extra heat. Frequent short trips, stop-and-go type traffic or extensive idling, prevent the engine from reaching normal operating temperature. This prevents component clearances from reaching specified operating ranges.

The following diagnostic procedure may be utilized to determine internal oil consumption. Make sure that the concern is related to internal oil consumption, and not external leakage, which also consumes oil. Verify there are no leaks before carrying out the test. Once verified, the rate of internal oil consumption can be tested.

A new engine may require extra oil in the early stages of operation. Internal piston-to-bore clearances and sealing characteristics improve as the engine breaks in. Engines are designed for close tolerances and do not require break-in oils or additives. Use the oil specified in the Owner's Literature. Ambient temperatures may determine the oil viscosity specification. Verify that the correct oil is being used for the vehicle in the geographic region in which it is driven.

Basic Pre-Checks

  1. For persistent complaints of oil consumption, interview the customer to determine the oil consumption characteristics. If possible, determine the brand and grade of oil currently in the oil pan. Look at the oil filter or oil-change station tags to determine if Ford-recommended maintenance schedules have been followed. Make sure that the oil has been changed at the specified mileage intervals. If vehicle mileage is past the first recommended drain interval, the OEM production filter should have been changed.
  2. Ask how the most current mileage was accumulated. That is, determine whether the vehicle was driven under the following conditions: Extended idling or curbside engine operation Stop-and-go traffic or taxi operation Towing a trailer or vehicle loaded heavily Frequent short trips (engine not up to normal operating temperature) Excessive throttling or high engine-RPM driving
  3. Verify that there are no external leaks. If necessary, review the diagnostic procedure under Engine Oil Leaks in the Diagnosis and Testing portion of this article.
  4. Inspect the crankcase ventilation system for: disconnected hoses at the valve cover or TB. loose or missing valve cover fill cap. missing or incorrectly seated engine oil level indicator. incorrect or dirty PCV valve. a PCV valve grommet unseated in the valve cover (if so equipped).
  5. Inspect for signs of sludge. Sludge affects PCV performance and can plug or restrict cylinder head drainback wells. It can also increase oil pressure by restricting passages and reducing the drainback capability of piston oil control rings. Sludge can result from either excessive water ingestion in the crankcase or operation at extremely high crankcase temperatures.
  6. Inspect the air filter for dirt, sludge or damage. A hole in the filter element will allow unfiltered air to bypass into the air induction system. This can cause premature internal wear (engine dusting), allowing oil to escape past rings, pistons, valves and guides.
  7. If the engine is hot or was recently shut down, wait at least 5 minutes to allow the oil to drain back. Ask the customer if this requirement has been followed. Adding oil without this wait period can cause an overfill condition, leading to excessive oil consumption and foaming which may cause engine damage.
  8. Make sure the oil level indicator is correctly and fully seated in the indicator tube. Remove the oil level indicator and record the oil level.

Detailed Pre-Checks

  1. Check the thermostat opening temperature to make sure that the cooling system is operating at the specified temperature. If it is low, internal engine parts are not running at specified internal operating clearances.
  2. Verify the spark plugs are not oil saturated. Oil leaking into one or more cylinders will appear as an oil soaked condition on the plug. If a plug is saturated, a compression check may be necessary at the conclusion of the oil consumption test.

Oil Consumption Test

Once all of the previous conditions are met, carry out an Oil Consumption Test.

  1. Drain the engine oil and remove the oil filter. Install a new manufacturer-specified oil filter. Make sure the vehicle is positioned on a level surface. Refill the oil pan to a level 1L (1 qt) less than the specified fill level, using manufacturer-specified oil.
  2. Run the engine for 3 minutes (if hot) or 10 minutes (if cold). Allow for a minimum 5-minute drainback period and then record the oil level shown on the oil level indicator. Place a mark on the backside of the oil level indicator noting the oil level location.
  3. Add the final 1L (1 qt) to complete the normal oil fill. Restart the engine and allow it to idle for 2 minutes. Shut the engine down.
  4. After a 5-minute drainback period, record the location of the oil level again. Mark the oil level indicator with the new oil level location. (Note: Both marks should be very close to the MIN-MAX upper and lower limits or the upper and lower holes on the oil level indicator. These marks will exactly measure the engine's use of oil, with a one quart differential between the new marks.) Demonstrate to the customer that the factory-calibrated marks on the oil level indicator are where the oil should fall after an oil change with the specified fill amount. Explain however, that this may vary slightly between MIN-MAX or the upper and lower holes on the oil level indicator.
  5. Record the vehicle mileage.
  6. Advise the customer that oil level indicator readings must be taken every 320 km (200 mi) or weekly, using the revised marks as drawn. Remind the customer that the engine needs a minimum 5-minute drainback for an accurate reading and that the oil level indicator must be firmly seated in the tube prior to taking the reading.
  7. When the subsequent indicator readings demonstrate a full liter (quart) has been used, record the vehicle mileage. The mileage driven between the 2 readings should not be less than 2,400 km (1,500 mi). The drive cycle the vehicle has been operated under must be considered when making this calculation. It may be necessary to have the customer bring the vehicle in for a periodic oil level indicator reading to closely monitor oil usage.

Post Checks, Evaluation and Corrective Action

  1. If test results indicate excessive oil consumption, carry out a cylinder compression test. The cylinder compression test should be carried out with a fully charged battery and all spark plugs removed. See the Compression Test Chart in this article for pressure range limits.
  2. Compression should be consistent across all cylinders. Refer to the Compression Testing portion of this article. If compression tested within the specifications found in this article, the excessive oil consumption may be due to wear on the valve guides, valves or valve seals.
  3. A cylinder leak detection test can be carried out using an Engine Cylinder Leak Detection/Air Pressurization Kit. This can help identify valves, piston rings or worn valve guides/valve stems, inoperative valve stem seals or other related areas as the source of oil consumption.
  4. If an internal engine part is isolated as the root cause, determine if the repair will exceed cost limits and proceed with a repair strategy as required.
  5. Once corrective action to the engine is complete and verification of all pre-check items were eliminated in the original diagnosis, repeat the Oil Consumption Test as described above and verify consumption results.

Intake Manifold Vacuum Test

Bring the engine to normal operating temperature. Connect the Vacuum/Pressure Tester to the intake manifold. Run the engine at the specified idle speed.

The vacuum gauge should read between 51-74 kPa (15-22 in-Hg), depending upon the engine condition and the altitude at which the test is performed. Subtract 4.0193 kPa (1 in-Hg) from the specified reading for every 304.8 m (1,000 ft) of elevation above sea level.

The reading should be steady. If necessary, adjust the gauge damper control (where used) if the needle is fluttering rapidly. Adjust the damper until the needle moves easily without excessive flutter.

Intake Manifold Vacuum Test - Interpreting Vacuum Gauge Readings

A careful study of the vacuum gauge reading while the engine is idling will help pinpoint trouble areas. Always conduct other appropriate tests before arriving at a final diagnostic decision. Vacuum gauge readings, although helpful, must be interpreted carefully.

Most vacuum gauges have a normal band indicated on the gauge face.

The following are potential gauge readings. Some are normal; others should be investigated further.

Scheme 4

Scheme 4: Intake Manifold Vacuum Test - Interpreting Vacuum Gauge Readings
  1. NORMAL READING: Needle between 51-74 kPa (15-22 in-Hg) and holding steady.
  2. NORMAL READING DURING RAPID ACCELERATION AND DECELERATION: When the engine is rapidly accelerated (dotted needle), the needle will drop to a low reading (not to zero). When the throttle is suddenly released, the needle will snap back up to a higher than normal figure.
  3. NORMAL FOR HIGH-LIFT CAMSHAFT WITH LARGE OVERLAP: The needle will register as low as 51 kPa (15 in-Hg) but will be relatively steady. Some oscillation is normal.
  4. WORN RINGS OR DILUTED OIL: When the engine is accelerated (dotted needle), the needle drops to 0 kPa (0 in-Hg). Upon deceleration, the needle runs slightly above 74 kPa (22 in-Hg).
  5. STICKING VALVES: When the needle (dotted) remains steady at a normal vacuum but occasionally flicks (sharp, fast movement) down and back about 13 kPa (4 in-Hg), one or more valves may be sticking.
  6. BURNED OR WARPED VALVES: A regular, evenly-spaced, downscale flicking of the needle indicates one or more burned or warped valves. Insufficient hydraulic lash adjuster clearance will also cause this reaction.
  7. POOR VALVE SEATING: A small but regular downscale flicking can mean one or more valves are not seating.
  8. WORN VALVE GUIDES: When the needle oscillates over about a 13 kPa (4 in-Hg) range at idle speed, the valve guides could be worn. As engine speed increases, the needle will become steady if guides are responsible.
  9. WEAK VALVE SPRINGS: When the needle oscillation becomes more violent as engine RPM is increased, weak valve springs are indicated. The reading at idle could be relatively steady.
  10. LATE VALVE TIMING: A steady but low reading could be caused by late valve timing.
  11. IGNITION TIMING RETARDING: Retarded ignition timing will produce a steady but somewhat low reading.
  12. INSUFFICIENT SPARK PLUG GAP: When spark plugs are gapped too close, a regular, small pulsation of the needle can occur.
  13. INTAKE LEAK: A low, steady reading can be caused by an intake manifold or throttle body gasket leak.
  14. BLOWN HEAD GASKET: A regular drop of fair magnitude can be caused by a blown head gasket or warped cylinder head-to-cylinder block surface.
  15. RESTRICTED EXHAUST SYSTEM: When the engine is first started and is idled, the reading may be normal, but as the engine RPM is increased, the back pressure caused by a clogged muffler, kinked tail pipe or other concerns will cause the needle to slowly drop to 0 kPa (0 in-Hg). The needle then may slowly rise. Excessive exhaust clogging will cause the needle to drop to a low point even if the engine is only idling.
  16. When vacuum leaks are indicated, search out and correct the cause. Excess air leaking into the system will upset the fuel mixture and cause concerns such as rough idle, missing on acceleration, or burned valves. If the leak exists in an accessory unit such as the power brake booster, the unit will not function correctly. Always fix vacuum leaks.

Oil Pressure Test

  1. Disconnect and remove the oil pressure sensor from the engine.
  2. Connect the Oil Pressure Gauge to the oil pressure sender oil galley port.
  3. Run the engine until normal operating temperature is reached.
  4. Run the engine at the specified RPM and record the gauge reading.
  5. The oil pressure should be within specifications; refer to the specification chart in the appropriate engine article.
  6. If the pressure is not within specification, check the following possible sources: Insufficient oil Oil leakage Worn or damaged oil pump Oil pump screen cover and tube Excessive main bearing clearance Excessive connecting rod bearing clearance

Valve Train Analysis - Engine Off - Valve Cover Removed

Check for damaged or severely worn parts and correct assembly. Make sure correct parts are used with the static engine analysis as follows

Valve Train Analysis - Valve Springs

  1. Check for broken or damaged parts.

Valve Train Analysis - Valve Spring Retainer and Valve Spring Retainer Keys

  1. Check for correct seating of the valve spring retainer key on the valve stem and in valve spring retainer.
  2. Check for correct seating on the valve stem.

Valve Train Analysis - Valves and Cylinder Head

  1. Check for plugged oil drain back holes.
  2. Check for worn or damaged valve tips.
  3. Check for missing or damaged guide-mounted valve stem seal.
  4. Check collapsed valve tappet gap.
  5. Check installed valve spring height.
  6. Check for missing or worn valve spring seats.
  7. Check for plugged oil metering orifice in cylinder head oil reservoir (4.6L engine only).

Valve Train Analysis - Camshafts

  1. Check for broken or damaged parts.
  2. Check for loose mounting bolts on camshaft caps.

Valve Train Analysis - Camshaft Lobe Lift

Check the lift of each camshaft lobe in consecutive order and make a note of the readings.

  1. Remove the valve covers. Refer to «ENGINE - 4.0L SOHC»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-40l-sohc) article or «ENGINE - 4.6L (3V)»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-46l-3v) article.
  2. Remove the spark plugs. Refer to «FUEL CHARGING AND CONTROLS - 4.0L SOHC»(/ford/explorer-sport-trac/ii-2006-2010/remont/fuel-system/#fuel-system-and-engine-controls-40l-sohc) article or «FUEL CHARGING AND CONTROLS - 4.6L (3V)»(/ford/explorer-sport-trac/ii-2006-2010/remont/fuel-system/#fuel-system-and-engine-controls-46l-3v) article.
  3. Install the Dial Indicator with Holding Fixture so the rounded tip of indicator is on top of the camshaft lobe.
  4. Rotate the crankshaft using a breaker bar and socket attached to the crankshaft pulley bolt. Rotate the crankshaft until the base circle of the camshaft lobe is reached.
  5. Zero the dial indicator. Continue to rotate the crankshaft until the (1) high-lift point of the camshaft lobe is in the fully-raised position (highest indicator reading).
  6. To check the accuracy of the original indicator reading, continue to rotate crankshaft until the (2) base circle is reached. The indicator reading should be zero. If zero reading is not obtained, repeat the measurement.
  7. If the lift on any lobe is below specified service limits, install a new camshaft and new camshaft roller followers. Refer to «ENGINE - 4.0L SOHC»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-40l-sohc) article or «ENGINE - 4.6L (3V)»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-46l-3v) article.
  8. Install the spark plugs. Refer to «FUEL CHARGING AND CONTROLS - 4.0L SOHC»(/ford/explorer-sport-trac/ii-2006-2010/remont/fuel-system/#fuel-system-and-engine-controls-40l-sohc) article or «FUEL CHARGING AND CONTROLS - 4.6L (3V)»(/ford/explorer-sport-trac/ii-2006-2010/remont/fuel-system/#fuel-system-and-engine-controls-46l-3v) article.
  9. Install the valve covers. Refer to «ENGINE - 4.0L SOHC»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-40l-sohc) article or «ENGINE - 4.6L (3V)»(/ford/explorer-sport-trac/ii-2006-2010/remont/mechanical/#engine-46l-3v) article.

Valve Train Analysis - Camshaft Roller Followers and Hydraulic Lash Adjusters

  1. Check for plugged oil feed in the camshaft roller followers, lash adjusters or cylinder heads.
  2. Check for collapsed hydraulic lash adjusters.

Excessive collapsed hydraulic lash adjuster gap can be caused by loose rocker arm seat bolts/nuts, incorrect initial adjustment or wear of hydraulic lash adjuster face, or worn roller hydraulic lash adjuster, push rod, rocker arm, rocker arm seat or valve tip. With hydraulic lash adjuster collapsed, check gap between the valve tip and the rocker arm to determine if any other valve train parts are damaged, worn or out of adjustment.

An incorrectly functioning hydraulic lash adjuster can be sticking, caused by contaminants or varnish inside the hydraulic lash adjuster. The hydraulic lash adjuster can have a check valve that is not functioning correctly, which can be caused by an obstruction, such as dirt or chips that prevent the check valve from closing, or a broken check valve spring. A hydraulic lash adjuster with a leakdown time out of specification can cause hydraulic lash adjuster noise. If no other cause for noisy hydraulic lash adjuster can be found, the leakdown rate should be checked and new hydraulic lash adjusters installed if found to be out of specification.

Assembled hydraulic lash adjusters can be tested with a commercially available leakdown tester to check the leakdown rate. The leakdown rate specification is the time in seconds for the plunger to move a specified distance while under a 22.7 kg (50 lb) load.

Air bubbles in the lubrication system will prevent the hydraulic lash adjuster from supporting the valve spring load. This can be caused by too high or too low an oil level in the oil pan or by air being drawn into the system through a hole, crack or leaking gasket on the oil pump screen cover and tube.

Sprockets

  1. Inspect the sprockets for cracks and worn or chipped teeth.

Camshaft Bearing Journal Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure each camshaft journal diameter in 2 directions.

Camshaft Journal to Bearing Clearance - OHC Engines

Note. Refer to the appropriate Engine article for the specification.

  1. Measure each camshaft bearing in 2 directions. Subtract the camshaft journal diameter from the camshaft bearing diameter.

Camshaft End Play - OHC Engines

Special Tools Illustration Tool Name Tool Number Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Dial Indicator Gauge with Holding Fixture, measure the camshaft end play.
  2. Position the camshaft to the rear of the cylinder head.
  3. Zero the Dial Indicator Gauge.
  4. Move the camshaft to the front of the cylinder head. Note and record the camshaft end play. If camshaft end play exceeds specifications, install a new camshaft and recheck end play. If camshaft end play exceeds specification after camshaft installation, install a new cylinder head.

Camshaft Surface Inspection

  1. Inspect camshaft lobes for pitting or damage in the contact area. Minor pitting is acceptable outside the contact area.

Camshaft Lobe Lift

Special Tools Illustration Tool Name Tool Number Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Use the Dial Indicator Gauge with Holding Fixture to measure camshaft intake/exhaust lobe lift. Rotate the camshaft and subtract the lowest indicator reading from the highest indicator reading to figure the camshaft lobe lift.

Camshaft Runout

Special Tools Illustration Tool Name Tool Number Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Dial Indicator Gauge with Holding Fixture, measure the camshaft runout. Rotate the camshaft and subtract the lowest indicator reading from the highest indicator reading.

Crankshaft Main Bearing Journal Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure each of the crankshaft main bearing journal diameters in at least 2 directions.

Crankshaft Main Bearing Journal Taper and Out-of-Round

Note. Refer to the appropriate Engine article for the specification.

  1. Measure each of the crankshaft main bearing journal diameters in at least 2 directions at each end of the main bearing journal.

Crankshaft Main Bearing Journal-to-Bearing Clearance

Note. Refer to the appropriate Engine article for the specification.

Note. Crankshaft main bearing journals must be within specifications before checking journal clearance.

  1. Remove the crankshaft main bearing caps and crankshaft main bearing.
  2. Lay a piece of Plastigage across the face of each crankshaft main bearing surface.
  3. Install and remove the crankshaft main bearing cap.
  4. Verify the crankshaft journal clearance.

Crankshaft End Play

Special Tools Illustration Tool Name Tool Number Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Install the Dial Indicator Gauge with Holding Fixture.
  2. Position the crankshaft to the rear of the cylinder block.
  3. Zero the Dial Indicator Gauge.
  4. Move the crankshaft to the front of the cylinder block. Note and record the crankshaft end play.

Crankshaft Runout

Special Tools Illustration Tool Name Tool Number Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Use the Dial Indicator Gauge with Holding Fixture to measure the crankshaft runout. Rotate the crankshaft and subtract the lowest Dial Indicator reading from the highest Dial Indicator reading to figure the crankshaft runout.

Connecting Rod Bearing Journal Taper and Out-of-Round

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the crankshaft connecting rod journal diameters in 2 directions perpendicular to one another at each end of the connecting rod journal. The difference in the measurements from one end to the other is the taper. Verify measurement is within the wear limit.

Cylinder Bore Taper

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the cylinder bore at the top, middle and bottom of piston ring travel in 2 directions as indicated. Verify the cylinder bore is within the wear limit. The difference indicates the cylinder bore taper. Bore the cylinder to the next oversize limit.

Cylinder Bore Out-of-Round

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the cylinder bore in 2 directions. The difference is the out-of-round.

Piston Inspection

Special Tools Illustration Tool Name Tool Number Scraper, Piston Ring Groove 303-D033 (D81L-6002-D) or equivalent

Note. Do not use a caustic cleaning solution or a wire brush to clean the pistons or damage can occur.

  1. Clean and inspect the (1) ring lands, (2) skirts, (3) pin bosses and the (4) tops of the pistons. If wear marks, scores or glazing is found on the piston skirt, check for a bent or twisted connecting rod.
  2. Use the Piston Ring Groove Scraper to clean the piston ring grooves. Make sure the oil ring holes are clean.

Piston Pin Bore Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the piston pin bore diameter in 2 directions on each side. Verify the diameter is within specification.

Piston Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the piston diameter 90 degrees from the piston pin and 42 mm (1.65 in) down from the top of the piston at the point indicated.

Piston To Cylinder Bore Clearance

Note. Refer to the appropriate Engine article for the specification.

  1. Subtract the piston diameter from the cylinder bore diameter to find the piston-to-cylinder bore clearance.

Piston Selection

Note. The cylinder bore must be within the specifications for taper and out-of-round before fitting a piston.

  1. Select a piston size based on the cylinder bore.
  2. Choose the piston with the correct paint color or specific size grade. Refer to the appropriate Engine article for the procedure.

Piston Ring End Gap

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Use care when fitting piston rings to avoid possible damage to the piston ring or the cylinder bore.

Note. Piston rings should not be transferred from one piston to another.

Note. Refer to the appropriate Engine article for the specification.

Note. The cylinder bore must be within specification for taper and out-of-round.

  1. Use a piston without rings to push a piston ring in a cylinder to the bottom of ring travel.
  2. Use the Feeler Gauge Set to measure the top piston ring end gap and the second piston ring end gap.

Piston Ring-to-Groove Clearance

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Inspect the piston for ring land damage or accelerated wear.
  2. Using the Feeler Gauge Set, measure the piston ring-to-groove clearance.

Piston Pin Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the piston pin diameter in 2 directions at the points shown. Verify the diameter is within specification.

Connecting Rod Cleaning

Note. Do not use a caustic cleaning solution or damage to connecting rods can occur.

  1. Mark and separate the parts and clean with solvent. Clean the oil passages.

Connecting Rod Large End Bore

Note. Refer to the appropriate Engine article for the specification.

  1. Tighten the bolts to specification, then measure the bore in 2 directions. The difference is the connecting rod bore out-of-round. Verify the out-of-round is within specification.

Connecting Rod to Crankshaft Side Clearance

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Feeler Gauge Set, measure the clearance between the connecting rod and the crankshaft. Verify the measurement is within specification.

Connecting Rod Bushing Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Use a telescoping gauge to determine the ID of the connecting rod bushing, if equipped.
  2. Measure the telescoping gauge with a micrometer. Verify the diameter is within specification.

Connecting Rod Bend

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Feeler Gauge Set, measure the connecting rod bend on a suitable alignment fixture. Follow the instructions of the fixture manufacturer. Verify the bend measurement is within specification.

Connecting Rod Twist

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Feeler Gauge Set, measure the connecting rod twist on a suitable alignment fixture. Follow the instructions of the fixture manufacturer. Verify the measurement is within specification.

Connecting Rod-to-Piston Clearance

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using the Feeler Gauge Set, measure the clearance between the connecting rod and the piston. Verify the measurement is within specification.

Connecting Rod Bearing Journal-to-Bearing Clearance

Note. Refer to the appropriate Engine article for the specification.

Note. The crankshaft connecting rod journals must be within specifications to check the connecting rod bearing journal clearance.

  1. Remove the connecting rod bearing cap.
  2. Position a piece of Plastigage across the bearing surface.
  3. Install and tighten to specifications, then remove the connecting rod bearing cap.
  4. Measure the Plastigage to get the connecting rod bearing journal clearance. The Plastigage should be smooth and flat. A changing width indicates a tapered or damaged connecting rod or connecting rod bearing.

Roller Follower Inspection

  1. Inspect the roller follower for flat spots or scoring. If any damage is found, inspect the camshaft lobes and hydraulic lash adjuster for damage.

Hydraulic Lash Adjuster Inspection

  1. Inspect the hydraulic lash adjuster and roller follower for damage. If any damage is found, inspect the camshaft lobes and valves for damage.

Valve Stem Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the diameter of each intake and exhaust valve stem at the points shown. Verify the diameter is within specification.

Valve Stem to Valve Guide Clearance

Special Tools Illustration Tool Name Tool Number Clearance Gauge, Valve Guide 303-004 (TOOL-6505-E) or equivalent Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent

Scheme 5

Scheme 5: Valve Stem to Valve Guide Clearance

Note. Refer to the appropriate Engine article for the specification.

Note. The valve stem diameter must be within specifications before checking valve stem-to-valve guide clearance.

  1. Install a Valve Guide Clearance Gauge on the valve stem and install a Dial Indicator Gauge with Holding Fixture. Lower the valve until the clearance gauge contacts the upper surface of the valve guide.
  2. Move the Valve Guide Clearance Gauge toward the Dial Indicator Gauge with Holding Fixture and zero the Dial Indicator Gauge. Move the Valve Guide Clearance Gauge away from the Dial Indicator Gauge with Holding Fixture and note the reading. The reading will be DOUBLE the valve stem-to-valve guide clearance.

Valve Inspection

  1. Inspect the following valve areas: The end of the stem for grooves or scoring. The valve face and the edge for pits, grooves or scores. The valve head for signs of burning, erosion, warpage and cracking. The valve margin for wear.

Valve Guide Inner Diameter

Note. Refer to the appropriate Engine article for the specification.

  1. Use a ball gauge to determine the inside diameter of the valve guides in 2 directions at the top, middle and bottom of the valve guide.
  2. Measure the ball gauge with a micrometer.
  3. If the valve guide is not within specifications, install a new cylinder head assembly.

Valve Spring Installed Length

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the installed length of each valve spring.

Valve Spring Free Length

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the free length of each valve spring.

Valve Spring Squareness

  1. Measure the out-of-square on each valve spring. Turn the valve spring and observe the space between the top of the valve spring and the square.

Valve Spring Strength

Special Tools Illustration Tool Name Tool Number Pressure Gauge, Valve/Clutch Spring 303-006 (TOOL-6513-DD) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Use the Valve/Clutch Spring Pressure Gauge to check the valve spring for correct strength at the specified valve spring length.

Valve and Seat Refacing Measurements

Note. Refer to the appropriate Engine article for the specification.

Note. After grinding valves or valve seats, check valve clearance.

  1. Check the valve head and seat. Check valve angles. Check margin width. Be sure margin width is within specification.
  2. Inspect for abnormalities on the valve face and seat. Install a new cylinder head assembly if abnormalities are found.

Valve Seat Width

Note. Refer to the appropriate Engine article for the specification.

  1. Measure the valve seat width. If necessary, grind the valve seat to specification. Measure the intake valve seat width. Measure the exhaust valve seat width. Recheck the valve spring installed length after the seats have been ground, and shim the valve springs as necessary to achieve the correct installed spring length.

Valve Seat Runout

Note. Refer to the appropriate Engine article for the specification.

  1. Use a valve seat runout gauge to check valve seat runout.

Cylinder Head Distortion

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Using a Straightedge and a Feeler Gauge Set, inspect the cylinder head for flatness in the sequence shown.

Cylinder Bore Cleaning

ItemSpecification
Motorcraft SAE 5W-20 Premium Synthetic Blend Motor Oil XO-5W20-QSP (US); Motorcraft SAE 5W-20 Super Premium Motor Oil CXO-5W20-LSP12 (Canada); or equivalentWSS-M2C930-A
Motorcraft SAE 5W-30 Premium Synthetic Blend Motor Oil XO-5W30-QSP (US); Motorcraft SAE 5W-30 Super Premium Motor Oil CXO-5W30-LSP12 (Canada); or equivalentWSS-M2C929-A

Material

  1. Clean the cylinder bores with soap or detergent and water.
  2. Thoroughly rinse with clean water and wipe dry with a clean, lint-free cloth.
  3. Use a clean, lint-free cloth and lubricate the cylinder bores. Use clean engine oil.

Core Plug Replacement

Special Tools Illustration Tool Name Tool Number Slide Hammer 100-001 (T50T-100-A)

Scheme 6

Scheme 6: Core Plug Replacement
ItemSpecification
LOCTITE® Retaining Compound 620 High Temperature Loctite 620/Permatex 62050WSK-N2G349-A9
Threadlock 262 TA-26WSK-M2G351-A6

Material

Note. It is necessary to use Loctite® Retaining Compound 620 High Temperature sealant on all 3 valve modular engine cylinder head cup plugs. If not used, the cylinder head cup plugs could leak or seep, causing serious engine damage.

All core plugs

  1. Use the Slide Hammer or a suitable tool to remove the core plug.
  2. Inspect the core plug bore for any damage that would interfere with the correct sealing of the plug. If the core plug bore is damaged, bore for the next oversize plug.
  3. Coat the cup-type core plug and bore lightly with sealant and install the core plug. Use a suitable tool to seat the cup-type core plug.
  4. Coat the expansion-type core plug and bore lightly with sealant and install the core plug. Use a suitable tool to seat the expansion-type core plug.

Cylinder Block Distortion

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

Note. Refer to the appropriate Engine article for the specification.

  1. Use a Straightedge and a Feeler Gauge Set to inspect the cylinder block for flatness.

Spark Plug Inspection

  1. Inspect the spark plug for a bridged gap. Check for deposit build-up closing the gap between the electrodes. Deposits are caused by oil or carbon fouling. Install a new spark plug.
  2. Check for oil fouling. Check for wet, black deposits on the insulator shell bore electrodes, caused by excessive oil entering the combustion chamber through worn rings and pistons, excessive valve-to-guide clearance or worn or loose bearings. Correct the oil leak concern. Install a new spark plug.
  3. Inspect for carbon fouling. Look for black, dry, fluffy carbon deposits on the insulator tips, exposed shell surfaces and electrodes, caused by a spark plug with an incorrect heat range, dirty air cleaner, too rich a fuel mixture or excessive idling. Install new spark plugs.
  4. Inspect for normal burning. Check for light tan or gray deposits on the firing tip.
  5. Inspect for pre-ignition, identified by melted electrodes and a possibly damaged insulator. Metallic deposits on the insulator indicate engine damage. This may be caused by incorrect ignition timing, wrong type of fuel or the unauthorized installation of a heli-coil insert in place of the spark plug threads. Install a new spark plug.
  6. Inspect for overheating, identified by white or light gray spots and with a bluish-burnt appearance of electrodes. This is caused by engine overheating, wrong type of fuel, loose spark plugs, spark plugs with an incorrect heat range, low fuel pump pressure or incorrect ignition timing. Install a new spark plug.
  7. Inspect for fused deposits, identified by melted or spotty deposits resembling bubbles or blisters. These are caused by sudden acceleration. Install new spark plugs.

Exhaust Manifold Cleaning and Inspection

Special Tools Illustration Tool Name Tool Number Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent

  1. Clean the exhaust manifold using a suitable solvent. Use a plastic scraping tool to clean the gasket sealing surfaces.
  2. Using the Straightedge and a Feeler Gauge Set, check the exhaust manifold sealing surface for warpage. If the warpage is greater than 0.76 mm (0.0299 in), install a new exhaust manifold.

Flexplate Inspection

  1. Inspect the flexplate for: any cracks. worn ring gear teeth. chipped or cracked ring gear teeth.

Bearing Inspection

  1. Inspect bearings for the following defects: Cratering - fatigue failure Spot polishing - incorrect seating Imbedded dirty engine oil Scratching - dirty engine oil Base exposed - poor lubrication Both edges worn - journal damaged One edge worn - journal tapered or bearing not seated

Powertrain/Drivetrain Mount Neutralizing

Note. Refer to the appropriate article and procedure for special instructions on loosening and tightening mount fasteners.

  1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING AND LIFTING»(/ford/explorer-sport-trac/ii-2006-2010/remont/hoistjack/#jacking-and-lifting) article.
  2. Loosen, but do not remove, the powertrain/drivetrain mount fasteners.
  3. Lower the vehicle.
  4. Start the vehicle and move it in forward 0.6-1.2 m (2-4 ft). Then move the vehicle in reverse the same distance.
  5. Raise and support the vehicle.
  6. Tighten the powertrain/drivetrain mount fasteners.
  7. Lower the vehicle.
  8. Test the system for normal operation.

See also:
Introduction - Gasoline Engines
ENGINE EMISSION CONTROL
EVAPORATIVE EMISSIONS
IDENTIFICATION CODES
MODULE COMMUNICATIONS NETWORK
MULTIFUNCTION ELECTRONIC MODULES
NOISE, VIBRATION AND HARSHNESS
CHARGING SYSTEM - GENERAL INFORMATION
ACCESSORY DRIVE
ENGINE COOLING
SUSPENSION SYSTEM - GENERAL INFORMATION
BRAKE SYSTEM - GENERAL INFORMATION
ENGINE - 4.0L SOHC
ENGINE - 4.6L (3V)
FUEL CHARGING AND CONTROLS - 4.0L SOHC
FUEL CHARGING AND CONTROLS - 4.6L (3V)
JACKING AND LIFTING
Symptom Chart - Engine Performance
Powertrain/Drivetrain Mount Neutralizing
Valve Guide Inner Diameter
Piston To Cylinder Bore Clearance
Piston Pin Bore Diameter
Piston Pin Diameter
Connecting Rod-to-Piston Clearance
Connecting Rod Bearing Journal-to-Bearing Clearance
Crankshaft Main Bearing Journal-to-Bearing Clearance
Flexplate Inspection