Inspection and Verification - Engine Performance
- Verify the customer concern by operating the engine to duplicate the condition.
- 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
- If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
- If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
- 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»(ref-494551) , No Power To The Scan Tool, to diagnose no power to the scan tool.
- 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»(ref-494551) to diagnose no response from the PCM.
- Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(ref-494551) . If the network test passes, retrieve and record continuous memory DTCs.
- Clear the continuous DTCs and carry out the self-test diagnostics for the PCM.
- If the DTCs retrieved are related to the concern, go to the DTC Charts, refer to «MULTIFUNCTION ELECTRONIC MODULES»(ref-494579) .
- If no DTCs related to the concern are retrieved, GO to «Symptom Chart - Engine»(ref-494566-S04691466732012081400000) .
Inspection and Verification - NVH
- 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 & HARSHNESS»(ref-494562) .
- Verify the customer concern by operating the engine to duplicate the condition.
- 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.
- 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) Damaged or disconnected air intake components
- If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
- If the cause is not visually evident, connect the scan tool to the DLC.
- 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»(ref-494551) , No Power To The Scan Tool, to diagnose no power to the scan tool.
- 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»(ref-494551) to diagnose no response from the PCM.
- Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(ref-494551) . If the network test passes, retrieve and record continuous memory DTCs.
- Clear the continuous DTCs and carry out the self-test diagnostics for the PCM.
- If the DTCs retrieved are related to the concern, go to the DTC Chart, refer to «MULTIFUNCTION ELECTRONIC MODULES»(ref-494579) .
- 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»(ref-494566-S11406989912012081400000) .
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
- Fuel injector(s)
- Upper end of engine
- Lower end of engine
- Front of engine
- Rear of engine
Symptom Chart - Engine Performance
| Condition | Possible Sources | Action |
|---|---|---|
| Difficult starting | Inoperative or damaged ignition system Air or vacuum leak Inoperative or damaged fuel system Inoperative or damaged starting system Damaged charging system/battery Burnt valve Worn piston Worn piston rings Worn cylinder Damaged head gasket Inoperative or damaged cooling system Fail-safe cooling invoked (if equipped) | Refer to the appropriate Engine article, for the procedure. REFER to the INTRODUCTION article. REFER to CHARGING SYSTEM . INSTALL a new valve in the cylinder head. TEST the system for normal operation after the repair. INSTALL a new piston. TEST the system for normal operation after the repair. INSTALL new piston rings. TEST the system for normal operation after the repair. INSTALL a new cylinder block. TEST the system for normal operation after the repair. INSTALL a new cylinder head gasket. TEST the system for normal operation after the repair. REFER to ENGINE COOLING . REFER to the INTRODUCTION article. |
| Poor idling | Vacuum leaks Inoperative or damaged ignition system Inoperative or damaged cooling system Inoperative or damaged fuel system Fail-safe cooling invoked (if equipped) Incorrect valve clearance Incorrect valve-to-valve seat contact Damaged head gasket | Refer to the appropriate Engine article, for the procedure. REFER to the INTRODUCTION article. REFER to ENGINE IGNITION - 3.5L . REFER to the INTRODUCTION article. ADJUST valve clearance. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. INSTALL a new cylinder head. TEST the system for normal operation after the repair. INSTALL a new cylinder head gasket. TEST the system for normal operation after the repair. |
| Engine runs rough | Inoperative or damaged fuel system Air or vacuum leaks Inoperative or damaged cooling system Inoperative or damaged ignition system Fail-safe cooling invoked (if equipped) Burnt or sticking valve Weak or broken valve spring Carbon accumulation in combustion chamber | Refer to the appropriate Engine article, for the procedure. REFER to the INTRODUCTION article. INSTALL a new valve in the cylinder head. TEST the system for normal operation after the repair. INSTALL a new valve spring. TEST the system for normal operation after the repair. ELIMINATE carbon buildup. TEST the system for normal operation after the repair. |
| Excessive oil consumption | Leaking oil Inoperative PCV system Incorrect oil Worn valve stem seal Worn valve stem or valve guide Sticking piston rings Worn piston ring groove Worn piston or cylinder | REPAIR oil leakage. TEST the system for normal operation after the repair. REPAIR or INSTALL new components as necessary. TEST the system for normal operation after the repair. CHANGE oil to correct specification. INSTALL a new valve stem seal. TEST the system for normal operation after the repair. INSTALL a new cylinder head. TEST the system for normal operation after the repair. INSTALL new piston rings. TEST the system for normal operation after the repair. INSTALL a new piston and piston pin. TEST the system for normal operation after the repair. INSTALL a new piston or cylinder block. TEST the system for normal operation after the repair. |
| Oil in coolant | Leaking head gasket Damaged cylinder block Damaged cylinder head | INSPECT the engine components. INSTALL new engine components as necessary. Refer to the appropriate Engine article, for the procedure. TEST the system for normal operation after the repair. |
| Coolant in oil | Leaking head gasket Damaged cylinder block Damaged cylinder head Damaged coolant pump/seal/gasket | INSPECT the engine components. INSTALL new engine components as necessary. Refer to the appropriate Engine article, for the procedure. TEST the system for normal operation after the repair. |
| Insufficient power | Inoperative or damaged ignition system Air intake system blockage Lubrication system blockage Inoperative or damaged fuel system Oil level too high Incorrect engine oil Excessive accessory drive belt loading Inoperative or damaged cooling system Fail-safe cooling invoked (if equipped) Damaged or plugged exhaust system Incorrect tire size Dragging brakes Slipping transmission Incorrect valve clearance Worn or damaged valve tappet Damaged valve guide Compression leakage at valve seat Seized valve stem Weak or broken valve spring Worn or damaged cam Damaged head gasket Cracked or distorted cylinder head Damaged, worn or sticking piston ring(s) Worn or damaged piston | Refer to the appropriate Engine article, for the procedure. REFER to the INTRODUCTION article. DRAIN oil to correct level. TEST the system for normal operation after the repair. INSTALL correct specification engine oil. TEST the system for normal operation after the repair. Refer to the appropriate Engine article, for the procedure. REFER to the INTRODUCTION article. INSPECT exhaust system. REFER to SUSPENSION SYSTEM - GENERAL INFORMATION . REFER to BRAKE SYSTEM - GENERAL INFORMATION . REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . ADJUST valve clearance. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. INSTALL a new valve tappet. TEST the system for normal operation after the repair. INSTALL a new cylinder head assembly. TEST the system for normal operation after the repair. INSTALL a new valve spring. TEST the system for normal operation after the repair. INSTALL a new camshaft. TEST the system for normal operation after the repair. INSTALL a new head gasket. TEST the system for normal operation after the repair. INSTALL a new cylinder head assembly. TEST the system for normal operation after the repair. INSTALL a new piston ring(s). TEST the system for normal operation after the repair. INSTALL a new piston and piston pin. TEST the system for normal operation after the repair. |
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 & HARSHNESS . 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 & HARSHNESS for the next likely system and continue diagnosis.
| Condition | Possible Sources | Action |
|---|---|---|
| Drone type noise | Powertrain mount(s) | CARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure. TEST the system for normal operation after the repair. |
| Drumming noise - occurs inside the vehicle during idle or high idle, hot or cold. Very low-frequency drumming is very rpm dependent. | Engine vibration excites the body resonances inducing interior noise | CARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure. TEST the system for normal operation after the repair. |
| Engine drumming noise - accompanied by vibration | Powertrain mount(s) | CARRY OUT the Powertrain/Drivetrain Mount Neutralizing procedure. TEST the system for normal operation after the repair. |
| Rattle - occurs at idle or at light acceleration from a stop | Powertrain mount(s) | CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, REFER to ENGINE - 3.5L . For transaxle, REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . TEST the system for normal operation after the repair. |
| Whine/moan type noise - pitch increases or changes with vehicle speed | Powertrain mount(s) | CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, REFER to ENGINE - 3.5L . For transaxle, REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . TEST the system for normal operation after the repair. |
| Clunk - occurs when shifting from PARK or between REVERSE and DRIVE | Powertrain mount(s) Idle speed is too high | CHECK the powertrain/drivetrain mounts for damage. INSTALL new mounts as necessary. For engine, REFER to ENGINE - 3.5L . For transaxle, REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . TEST the system for normal operation after the repair. CHECK 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 day | Accessory drive idler or tensioner pulley bearing is experiencing stick/slip between ball bearings and the bearing race | CARRY OUT the engine cold soak procedure. REFER to NOISE, VIBRATION & HARSHNESS . 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 ACCESSORY DRIVE . TEST the system for normal operation after the repair. |
| Accessory drive belt noise, squeal or chirping | Defective/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 grooves | CARRY OUT the Engine Accessory Test. REFER to NOISE, VIBRATION & HARSHNESS . INSPECT components and INSTALL new parts as necessary. REFER to ACCESSORY DRIVE . TEST the system for normal operation after the repair. |
| Clunking noise | Coolant pump has excessive end play or imbalance | CHECK 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 . TEST the system for normal operation after the repair. |
| Whine or moaning noise | Air intake system | CHECK the air cleaner and ducts for correct fit. INSPECT the air intake system for leaks or damage. REPAIR as necessary. TEST the system for normal operation after the repair. |
| Whistling noise - normally accompanied with poor idle condition | Air intake system | CHECK the air intake ducts, air cleaner, throttle body and vacuum hoses for leaks and correct fit. REPAIR or ADJUST as necessary. TEST the system for normal operation after the repair. |
| Hissing noise - occurs during idle or high idle that is apparent with the hood open | Vacuum leak Vehicles with a plastic intake manifold | USE 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. TEST the system for normal operation after the repair. Acceptable condition. Some plastic manifolds exhibit this noise, which is the effect of the plastic manifold. |
| Grinding noise - occurs during engine cranking | Incorrect starter motor mounting Starter motor Incorrect starter motor drive engagement | INSPECT the starter motor for correct mounting. REPAIR as necessary. REFER to STARTING SYSTEM . TEST the system for normal operation after the repair. CHECK the starter motor. INSTALL a new starter motor as necessary. REFER to STARTING SYSTEM . TEST the system for normal operation after the repair. INSPECT the starter motor drive for wear or damage. INSTALL a new starter motor as necessary. REFER to STARTING SYSTEM . TEST the system for normal operation after the repair. INSPECT the flexplate for wear or damage. INSTALL a new flexplate as necessary. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. |
| Engine noise, front of engine - knocking noise from lower front of engine | Damaged or separated crankshaft pulley/damper | CHECK for obvious signs of damage or wobble during operation. INSTALL new as necessary. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. |
| Engine noise, front of engine - ticking, tapping or rattling noise from the front of the engine | Timing drive components | REMOVE the accessory drive belt. REFER to ACCESSORY DRIVE . 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 ENGINE - 3.5L . TEST the system for normal operation after the repair. |
| Engine noise, upper end - ticking noise near the fuel rail and intake manifold | Fuel rail clip Fuel injector | CHECK for loose or damaged fuel rail clip(s). REPAIR as necessary. TEST the system for normal operation after the repair. USE the EngineEAR to isolate the noisy injector(s). INSTALL a new injector(s) as necessary. REFER to FUEL CHARGING AND CONTROLS - 3.5L . TEST the system for normal operation after the repair. |
| Engine noise, upper end - occurs mostly with a warm engine at light/medium acceleration | Worn or damaged spark plugs Carbon accumulation in combustion chamber | REMOVE the spark plugs. INSPECT and INSTALL new as necessary. REFER to ENGINE IGNITION - 3.5L . TEST the system for normal operation after the repair. Bore scope the cylinder. ELIMINATE carbon buildup. TEST the system for normal operation after the repair. |
| Engine noise, upper end - rattling noise from the valve train. Worse when the engine is cold | Low oil level Thin or diluted oil Low oil pressure Worn valve train components Worn valve guides Excessive runout of the valve seats on the valve face | CHECK the oil level. FILL as necessary. INSPECT the oil for contamination. If the oil is contaminated, CHECK for the source. REPAIR as necessary. CHANGE the oil and filter. TEST the system for normal operation after the repair. CARRY OUT an Oil Pressure Test . If not within specifications, REMOVE the engine oil pan. REFER to ENGINE - 3.5L . INSPECT for a blocked oil pick up tube. TEST the system for normal operation after the repair. CARRY OUT the Valve Train Analysis . INSTALL new parts as necessary. TEST the system for normal operation after the repair. CARRY OUT the Valve Guide Inner Diameter procedure. CARRY OUT the Valve Seat Inspection procedure. |
| Engine noise, upper end - pinging noise | Gasoline octane too low Knock Sensor (KS) operation Incorrect spark timing High operating temperature Spark plug Catalytic converter | VERIFY with customer the type of gasoline used. CORRECT as necessary. TEST the system for normal operation after the repair. CHECK the KS. INSTALL a new KS as necessary. REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation after the repair. CHECK the spark timing. REPAIR as necessary. TEST the system for normal operation after the repair. INSPECT 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. TEST the system for normal operation after the repair. CHECK the spark plugs. INSTALL new spark plugs as necessary. TEST the system for normal operation after the repair. Acceptable noise. |
| Engine noise, lower end - ticking or knocking noise near the oil filter adapter | Oil pump | USE the EngineEAR to verify the oil pump as the source of the noise at low rpm. REPAIR as necessary. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. |
| 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 warms | Excessive clearance between the piston and the cylinder wall | CARRY 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 history | Excessive clearance between the piston and the piston pin | CARRY OUT the Piston Pin Bore Diameter and the Piston Pin Diameter procedures. |
| 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 NEUTRAL | Excessive clearance between the connecting rod bearings and the crankshaft | CARRY 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 float | Worn or damaged crankshaft main bearings | CARRY OUT the Crankshaft Main Bearing Journal-to-Bearing Clearance procedure. |
| Engine noise, rear of engine - knocking noise at rear of engine | Damaged flywheel/flexplate | CARRY OUT the Flexplate Inspection procedure. |
| Engine vibration - vibration felt at all times | Excessive engine pulley runout Damaged or worn accessory component | CARRY OUT the Engine Accessory Test. REFER to NOISE, VIBRATION & HARSHNESS . INSTALL a new engine pulley as necessary. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. CARRY OUT the Engine Accessory Test. REPAIR or INSTALL a new component as necessary. TEST the system for normal operation after the repair. |
| Engine vibration - at idle, a low-frequency vibration (5-20 Hz) or mild shake that is felt through the seat/floorpan | Cylinder misfire Engine or torque converter out of balance | Using the scan tool, CARRY OUT the cylinder power balance and the relative compression test. REPAIR as necessary. REFER to ENGINE - 3.5L . TEST the system for normal operation after the repair. VERIFY the torque converter-to-crankshaft pilot clearance is correct. REPAIR as necessary. RE-INDEX the torque converter on the flexplate by 120 degrees for a 3-bolt converter or 180 degrees for a 4-bolt converter. REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 for the transaxle. TEST the system for normal operation after the repair. |
| Engine vibration - is felt with increases and decreases in engine rpm | Powertrain mount(s) Engine or transmission grounded to chassis | CHECK the powertrain mounts for damage. INSTALL new mounts as necessary. For engine, REFER to ENGINE - 3.5L . For the transaxle, REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . TEST the system for normal operation after the repair. INSPECT the powertrain/drivetrain for correct clearances. REPAIR as necessary. TEST the system for normal operation after the repair. |
| Engine vibration - increases intensity as the engine rpm is increased | Engine out-of-balance | CARRY OUT the Neutral Engine Run-Up (NERU) Test. REFER to NOISE, VIBRATION & HARSHNESS . 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 AUTOMATIC TRANSMISSION - 6F50/6F55 . TEST the system for normal operation after the repair. |
| Engine vibration - mostly at coast/neutral coast. Condition improves with vehicle acceleration | Combustion instability | CHECK the ignition system. INSTALL new components as necessary. REFER to ENGINE IGNITION - 3.5L . TEST the system for normal operation after the repair. |
| Engine vibration or shudder - occurs with light to medium acceleration above 56 km/h (35 mph) | Worn or damaged spark plugs Plugged fuel injector Contaminated fuel | INSPECT the spark plugs for cracks, high resistance or broken insulators. INSTALL a new spark plug(s) as necessary. REFER to ENGINE IGNITION - 3.5L . TEST the system for normal operation after the repair. REPAIR or INSTALL a new injector as necessary. REFER to FUEL CHARGING AND CONTROLS - 3.5L . TEST the system for normal operation after the repair. INSPECT the fuel for contamination. DRAIN the fuel system and refill. REFER to FUEL SYSTEM - GENERAL INFORMATION . |
SYMPTOM CHART - NVH
Compression Test
- 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.
- Set the throttle plates in the wide-open position.
- Install a compression gauge in the No. 1 cylinder.
- 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 necessary to obtain the highest reading.
- 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 .
Scheme 2260
If one or more cylinders reads low, squirt approximately one tablespoon of engine oil meeting Ford specification on top of the pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.
Compression Test - Interpreting Compression Readings
- If compression improves considerably, piston rings are worn or damaged.
- If compression does not improve, valves are sticking or not seating correctly.
- 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 within 75% of the highest reading.
Oil Consumption Test
Once all of the previous conditions are met, carry out an oil consumption test.
- 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 one liter (quart) less than the specified fill level, using manufacturer-specified oil.
- 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.
- Add the final one liter (quart) to complete the normal oil fill. Restart the engine and allow it to idle for 2 minutes. Shut the engine down.
- 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.
- Record the vehicle mileage.
- 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.
- 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 4, 800 km (3, 000 miles). 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.
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 conducted. 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 2261
- NORMAL READING: Needle between 51-74 kPa (15-22 in-Hg) and holding steady.
- 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.
- 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.
- 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).
- 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.
- BURNED OR WARPED VALVES: A regular, evenly-spaced, downscale flicking of the needle indicates one or more burned or warped valves. Insufficient valve clearance will also cause this reaction.
- POOR VALVE SEATING: A small but regular downscale flicking can mean one or more valves are not seating.
- 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.
- 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.
- LATE VALVE TIMING: A steady but low reading could be caused by late valve timing.
- IGNITION TIMING RETARDING: Retarded ignition timing will produce a steady but somewhat low reading.
- INSUFFICIENT SPARK PLUG GAP: When spark plugs are gapped too close, a regular, small pulsation of the needle can occur.
- INTAKE LEAK: A low, steady reading can be caused by an intake manifold or throttle body gasket leak.
- 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.
- 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 tailpipe 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.
- 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
- Disconnect and remove the oil pressure switch from the engine.
- Connect the engine Oil Pressure Gauge to the oil pressure switch oil galley port.
- Run the engine until normal operating temperature is reached.
- Run the engine at the specified rpm and record the gauge reading.
- The oil pressure should be within specifications; refer to the «specification»(ref-494566-S10272786992012081400000) chart in the appropriate engine service information.
- 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 Chain tensioner leak
Camshaft Surface Inspection
- Inspect camshaft lobes for pitting or damage in the contact area. Minor pitting is acceptable outside the contact area.
Scheme 2262
Piston Inspection
SPECIAL TOOLS DESCRIPTION CHART Scraper, Piston Ring Groove 303-D033 (D81L-6002-D) or equivalent
Scheme 2263
Note. Do not use a caustic cleaning solution or a wire brush to clean the pistons or damage can occur.
Scheme 2264
- 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.
- Use the Piston Ring Groove Scraper to clean the piston ring grooves.
- Make sure the oil ring holes are clean.
Scheme 2265
Exhaust Manifold Cleaning and Inspection
SPECIAL TOOLS DESCRIPTION CHART Feeler Gauge Set 303-D027 (D81L-4201-A) or equivalent
- Clean the exhaust manifold using a suitable solvent. Use a plastic scraping tool to clean the gasket sealing surfaces.
- 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.
Scheme 2266
Valve Tappet Inspection
- Inspect the valve tappet for damage, especially in the indicated areas. If any damage is evident, inspect the camshaft lobes and valves for damage. Install new components as necessary.