Engine System - General Information Ford Explorer Sport Trac I

SPECIFICATIONS

General Specifications (1 Of 2)

General Specifications (2 Of 2)

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

This section covers general procedures and diagnosis and testing of the engine system, except for exhaust emission control devices, which are covered in the Powertrain Control/Emissions Diagnosis Manual.

The engine incorporates the following features

1. A closed positive crankcase ventilation (PCV) system.
2. An exhaust emission control system.
3. An evaporative emission control system.

Some engines incorporate a fail-safe cooling system.

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.

Scheme 1

Scheme 2

Scheme 3

Scheme 4

1. Verify the customer concern by operating the engine to duplicate the condition.
2. Visually inspect for obvious signs of mechanical damage. Refer to engine visual inspection chart. (Scheme 4)
3. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
4. If the concerns remain after the inspection, determine the symptoms. Go to «SYMPTOM CHART»(/ford/explorer-sport-trac/i-2000-2005/remont/mechanical/#engine-system-general-information).

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Engine Oil Leaks

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 gasoline engine oil dye. Use a minimum 14.8 ml (0.5 ounce) to a maximum 29.6 ml (1 ounce) of fluorescent additive to all engines. If the oil is not premixed, fluorescent additive must first be added to crankcase.
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.

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 & 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 (6710)
2. Oil Pan Sealer
3. Oil Pan Rear Seal (6723)
4. Engine Front Cover Gasket
5. Crankshaft Front Seal (6700)
6. Crankshaft Rear Oil Seal (6701)
7. Crankshaft Main Bearing Cap Side Bolts
8. Oil Filter Adapter & Filter Body
9. Oil Cooler, If Equipped

Leakage Points - With Transmission & 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 (6266) 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 (10655) 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 (12405).
2. Set the throttle plates in the wide-open position.
3. Install a compression gauge such as the 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 five 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 within 75 percent of the highest reading. Refer to the Compression Pressure Limit Chart. (Scheme 9)or (Scheme 10).

If one or more cylinders reads 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.

Scheme 9

Scheme 10

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 two 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 percent of the highest reading. (Scheme 9)or (Scheme 10).

Cylinder Leakage Detection

When a cylinder produces a low reading, 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 percent is excessive.

While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak at the intake valve (6507) will be heard in the throttle body (9E926). A leak at the exhaust valve (6505) can be heard at the tail pipe. Leakage past the piston rings will be audible at the positive crankcase ventilation (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 (8005).

Oil Consumption Test

The following diagnostic procedure is used to determine the source of excessive internal oil consumption.

1. Define excessive oil consumption, such as the number of miles driven per liter (quart) of oil used. Also determine customer's driving habits, such as sustained high speed operation, towing, extended idle and other considerations.
2. Verify that the engine has no external oil leak as described under «ENGINE OIL LEAKS»(/ford/explorer-sport-trac/i-2000-2005/remont/mechanical/#engine-system-general-information__engine-oil-leaks) .
3. Verify that the engine has the correct oil level dipstick (6750).
4. Verify that the engine is not being run in an overfilled condition. Check the oil level at least five minutes after a hot shutdown with the vehicle parked on a level surface. In no case should the level be above MAX or the letter F in FULL. If significantly overfilled, carry out Steps 6a through 6d.
5. Verify the spark plugs are not oil saturated. If the spark plugs are oil saturated and compression is good it can be assumed the valve seals or valve guides are at fault.
6. Carry out an oil consumption test: Drain the engine oil, remove the oil bypass filter (6714) and refill with one liter (quart) less than the recommended amount. Run the engine for three minutes (10 minutes if cold), and allow the oil to drain back for at least five minutes with the vehicle on a level surface. Remove oil level dipstick and wipe clean. (Do not wipe with anything contaminated with silicone compounds.) Reinstall the oil level dipstick, being sure to seat it firmly in the oil level indicator tube (6754). Remove the oil level dipstick and draw a mark on the back (unmarked) surface at the indicated oil level. This level should be about the same as the MIN or ADD mark on the face of the oil level dipstick. Add one liter (quart) of oil. Restart the engine and allow to idle for at least two minutes. Shut off the engine and allow the oil to drain back for at least five minutes. Mark the oil level dipstick, using the procedure above. Record the vehicle mileage. Instruct the customer to drive the vehicle as usual and perform the following: Check the oil level regularly at intervals of 160 to 240 km (100-150 miles). Return to the service point when the oil level drops below the lower (MIN or ADD) mark on the oil level dipstick. Add only full liters (quarts) of the same oil in an emergency. Note the mileage at which the oil is added. Check the oil level under the same conditions and at the same location as in Steps 6c and 6d. Measure the distance from the oil level to the UPPER mark on the oil level dipstick and record. Measure the distance between the two scribe marks and record. Divide the first measurement by the second. Divide the distance driven during the oil test by the result. This quantity is the approximate oil consumption rate in kilometers per liter or in miles per quart. If the oil consumption rate is unacceptable, go to Step 7.
7. Check the positive crankcase ventilation (PCV) system. Make sure the system is not plugged.
8. Check for plugged oil drain-back holes in the cylinder heads and cylinder block.
9. If the condition still exists after performing the above steps, go to Step 10.
10. Perform a cylinder compression test or perform a cylinder leak detection test with Engine Cylinder Leak Detection/Air Pressurization Kit. This can help determine the source of oil consumption such as valves, piston rings or other areas.
11. Check valve guides for excessive guide clearance. Install new all valve stem seals (6571) after verifying valve guide clearance.
12. Worn or damaged internal engine components can cause excessive oil consumption. Small deposits of oil on the tips of spark plugs can be a clue to internal oil consumption. If internal oil consumption still persists, proceed as follows: Remove the engine from the vehicle and place it on an engine work stand. Remove the intake manifolds (9424), cylinder heads, oil pan (6675) and oil pump (6600). Check piston ring clearance, ring gap and ring orientation. Repair as necessary. Check for excessive bearing clearance. Repair as necessary.
13. Repeat the oil consumption test (Step 6) to confirm the oil consumption concern has been resolved.

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 (1000 feet) 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.

1. NORMAL READING: Needle between 51-74 kPa (15-22 in-Hg) and holding steady.
2. NORMAL READING DURING RAPID ACCELERATION & 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 or hydraulic lash adjuster (HLA) 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 (5230), 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 (2005), the unit will not function correctly. Always fix vacuum leaks.

Excessive Engine Oil Consumption

The amount of oil an engine uses will vary with the way the vehicle is driven in addition to normal engine-to-engine variation. This is especially true during the first 16,100 km (10,000 miles) when a new engine is being broken in or until certain internal engine components become conditioned. Vehicles used in heavy-duty operation may use more oil. The following are examples of heavy-duty operation

1. Trailer Towing Applications
2. Severe Loading Applications
3. Sustained High Speed Operation

Engines need oil to lubricate the following internal components

1. Cylinder Block Cylinder Walls
2. Pistons And Piston, Pin & Rings (6102)
3. Intake And Exhaust Valve Stems
4. Intake And Exhaust Valve Guides
5. All Internal Engine Components

When the pistons move downward, a thin film of oil is left on the cylinder walls. As the vehicle is operated, some oil is also drawn into the combustion chambers past the intake and exhaust valve stem seals and burned.

The following is a partial list of conditions that can affect oil consumption rates

1. Engine Duty Cycle
2. Operator Driving Habits
3. Ambient Temperature
4. Quality & Viscosity Of The Oil

Operation under varying conditions can frequently be misleading. A vehicle that has been run for several thousand miles on short trips or in below-freezing ambient temperatures may have consumed a "normal" amount of oil. However, when checking the engine oil level, it may measure up to the FULL or MAX on the oil level dipstick due to dilution (condensation and fuel) in the engine crankcase. The vehicle might then be driven at high speeds on the highway where the condensation and fuel boil off. The next time the engine oil is checked, it may appear that a liter (quart) of oil was used in about 160 km (100 miles). This perceived 160 km (100 miles) per liter (quart) oil consumption rate causes customer concern even though the actual overall oil consumption rate is about 2,400 km (1,500 miles) per liter (quart).

Make sure the selected engine oil meets the current recommended API performance category with SAE viscosity grade as shown in the vehicle Owner's Guide. It is also important that the engine oil is changed at the intervals specified. Refer to the vehicle Owner's Guide.

Oil Pressure Test

1. Disconnect and remove the oil pressure sensor (9278) 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 section.
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 & Tube (6622) 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 - Engine Off, Rocker Arm

1. Check for loose mounting bolts, studs and nuts.
2. Check for plugged oil feed in the rocker arms (6564) or cylinder head.

Valve Train Analysis - Engine Off, Camshaft Roller Followers & Hydraulic Lash Adjusters, Overhead Camshaft

1. Check for loose mounting bolts on camshaft carriers.
2. Check for plugged oil feed in the camshaft roller followers, lash adjusters or cylinder heads.

Valve Train Analysis - Engine Off, Camshaft - Engines

1. Check for broken or damaged parts.

Valve Train Analysis - Engine Off, Push Rods

1. Check for bent push rods (6565) and restricted oil passage.

Valve Train Analysis - Valve Springs

1. Check for broken or damaged parts.

Valve Train Analysis - Engine Off, Valve Spring Retainer & Valve Spring Retainer Keys

1. Check for correct seating of the valve spring retainer key (6518) on the valve stem and in valve spring retainer (6514).
2. Check for correct seating on the valve stem.

Valve Train Analysis - Engine Off, Valves & 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 (if equipped).

Static checks (engine off) are to be made on the engine prior to the dynamic procedure.

Valve Train Analysis - Engine Running

1. Start the engine and, while idling, check for correct operation of all parts. Check the following

Valve Train Analysis - Engine Running, Valves & Cylinder Head

1. Check for plugged oil drain back holes.
2. Check for missing or damaged valve stem seals or guide mounted valve stem seals.
3. Check for a plugged oil metering orifice in the cylinder head oil reservoir (4.6L engine only).

If insufficient oiling is suspected, check oil passages for blockage, then accelerate the engine to 1,200 rpm with the transmission in NEUTRAL and the engine at normal operating temperature. Oil should spurt from the rocker arm oil holes such that valve tips and camshaft roller followers are well oiled. With the valve covers (6582) off, some oil splash may overshoot camshaft roller followers.

Valve Train Analysis - Engine Running, Camshaft Lobe Lift - OHC Engines

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

Scheme 11

1. Remove the valve covers.
2. Remove the spark plugs.
3. Install the Dial Indicator Gauge with Holding Fixture so the rounded tip of indicator is on top of the camshaft lobe and on the same plane as the valve tappet.
4. Rotate the crankshaft using a breaker bar and socket attached to the crankshaft pulley retainer 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). (Scheme 12)
6. To check the accuracy of the original indicator reading, continue to rotate crankshaft until the (2) base circle is reached. (Scheme 12) The indicator reading should be zero. If zero reading is not obtained, repeat Steps 1 through 6.
7. Remove the Dial Indicator Gauge with Holding Fixture.
8. Install the spark plugs.
9. Install the valve covers.

Valve Train Analysis - Engine Running, Camshaft Lobe Lift - Push Rod Engine

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

Scheme 12

1. Remove the valve covers.
2. Remove the rocker arm seat bolts, rocker arm seat (6A528) and rocker arms.
3. Make sure the valve tappet is seated against camshaft (6250). Install (1) Dial Indicator Gauge with Holding Fixture so the ball socket adapter of the indicator is on top of the valve tappet or (2) Dial Indicator Gauge Adapter is on top of push rod and in same plane as valve tappet push rod movement. (Scheme 13)
4. Remove the spark plugs.
5. Connect an auxiliary starter switch in the starting circuit. Crank the engine with ignition switch in OFF position. Bump crankshaft over until valve tappet is on base circle of camshaft lobe. At this point, valve tappet will be in its lowest position. If checking during engine assembly, turn crankshaft using a socket or ratchet.
6. Zero the dial indicator. Continue to rotate crankshaft slowly until valve tappet is in fully-raised position (highest indicator reading).
7. Remove the Dial Indicator with Holding Fixture, Dial Indicator Gauge Adapter, and auxiliary starter switch.
8. Install rocker arm seats, rocker arms and rocker arm seat bolts.
9. Install valve covers.
10. Install spark plugs.

Valve Train Analysis - Engine Running, Valve Tappet

Valve tappet noise can be caused by any of the following

1. Excessive Valve Tappet Gap (Collapsed)
2. Incorrectly Functioning Valve Tappet
3. Air In Lubrication System
4. Excessive Valve Guide Wear
5. Low Oil Pressure

Excessive collapsed valve tappet gap can be caused by loose rocker arm seat bolts/nuts, incorrect initial adjustment or wear of valve tappet face, or worn roller valve tappets, push rod (6565), rocker arm (6564), rocker arm seat or valve tip. With valve tappet 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 valve tappet can be sticking, caused by contaminants or varnish inside the tappet. The tappet 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 tappet with a leakdown time out of specification can cause tappet noise. If no other cause for noisy valve tappets can be found, the leakdown rate should be checked and new valve tappets installed if found to be out of specification.

Assembled valve tappets can be tested with Hydraulic Tappet 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 valve tappet 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.

Scheme 13

1. Measure each camshaft journal diameter in two directions. If out of specification, install new components as necessary.

Scheme 14

Camshaft Journal - Clearance, Plastigage Method

Note. The camshaft journals must meet specifications before checking camshaft journal clearance.

1. Remove the camshaft bearing cap and lay Plastigage across the surface.
2. Position the camshaft bearing cap and install the bolts.
3. Use Plastigage to verify the camshaft journal clearance. If out of specification, install new components as necessary.

Scheme 15

Scheme 16

1. Remove the roller followers.
2. Use a Dial Indicator Gauge with Holding Fixture to measure camshaft end play.
3. Position the camshaft to the rear of the cylinder head.
4. Zero the indicator.
5. Move the camshaft to the front of the cylinder head. Note and record the camshaft end play. If camshaft end play exceeds specifications, install new camshaft and recheck end play. Refer to the appropriate section in Group 303 for the procedure. If camshaft end play exceeds specification after camshaft installation, install a new cylinder head.

Scheme 17

1. Inspect camshaft lobes for pitting or damage in the contact area. Minor pitting is acceptable outside the contact area. If excessive pitting or damage is present, install new components as necessary.

Scheme 18

Scheme 19

1. Use a 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.

Scheme 20

Checking Camshaft Runout

1. Use a Dial Indicator Gauge with Holding Fixture to measure the camshaft runout. Rotate the camshaft and subtract the lowest indicator reading from the highest indicator reading. For additional information, refer to the specification chart. See «GENERAL SPECIFICATIONS»(/ford/explorer-sport-trac/i-2000-2005/remont/mechanical/#engine-40l-sohc__general-specifications) in ENGINE article. If out of specification, install new components as necessary.

Scheme 21

1. Measure each of the crankshaft main bearing journal diameters in at least two directions. If out of specification, install new components as necessary.

Scheme 22

1. Measure each of the crankshaft main bearing journal diameters in at least two directions at each end of the main bearing journal. If out of specification, install new components as necessary.

Scheme 23

Crankshaft Main Bearing Journal - Clearance

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

Scheme 24

Scheme 25

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. If out of specification, install new components as necessary.

Scheme 26

Scheme 27

1. Measure the crankshaft end play. Use a Dial Indicator Gauge with Holding Fixture to measure crankshaft end play.
2. Position the crankshaft to the rear of the cylinder block.
3. Zero the indicator.
4. Move the crankshaft to the front of the cylinder block. Note and record the crankshaft end play. If crankshaft end play exceeds specifications, install a new crankshaft thrust washer (6334) or crankshaft thrust main bearing (6337).

Scheme 28

Crankshaft Runout

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. If it is out of specification, install new components as necessary.

Scheme 29

1. Measure the crankshaft connecting rod journal diameters in two 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. If out of specification, install new components as necessary.

Scheme 30

1. Measure the cylinder bore at the top, middle, and bottom of piston ring travel in two 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.

Scheme 31

1. Measure the cylinder bore in two directions. The difference is the out-of-round. Verify the out-of-round is within the wear limit and bore the cylinder to the next oversize limit.

Scheme 32

Piston Inspection

Scheme 33

Scheme 34

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 TO BORE DIAMETER

1. Measure the piston pin bore diameter in two directions on each side. Verify the diameter is within specification. If out of specification, install new components as necessary.

Scheme 35

1. Measure the piston diameter 90 degrees from the piston pin at the point indicated. If out of specification, install new components as necessary.

PISTON - TO CYLINDER BORE CLEARANCE

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.

Scheme 36

1. Select a piston size based on the cylinder bore.
2. Choose the piston with the correct paint color.

PISTON - RING END GAP

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

Scheme 37

Scheme 38

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

Scheme 39

Scheme 40

1. Inspect the piston for ring land damage or accelerated wear.
2. Measure the piston ring-to-groove clearance. If out of specification, install new components as necessary.

Scheme 41

1. Measure the piston pin diameter in two directions at the points shown. Verify the diameter is within specification. If out of specification, install new components as necessary.

CONNECTING ROD - CLEANING

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

Scheme 42

1. Tighten the bolts to specification, then measure the bore in two directions. The difference is the connecting rod bore out-of-round. Verify the out-of-round is within specification. If out of specification, install now components as necessary.

Scheme 43

1. Measure the inner diameter of the connecting rod bushing, if equipped. Verify the diameter is within specification. If out of specification, install new components as necessary.

Scheme 44

1. Measure the connecting rod bend on a suitable alignment fixture. Follow the instructions of the fixture manufacturer. Verify the bend measurement is within specification. If out of specification, install new components as necessary.

Scheme 45

1. Measure the connecting rod twist on a suitable - alignment fixture. Follow the instructions of the fixture manufacturer. Verify the measurement is within specification. If out of specification, install new components as necessary.

Scheme 46

1. Measure the clearance between the connecting rod and the piston. Verify the measurement is within specification. If out of specification, install new components as necessary.

Scheme 47

Connecting Rod - Bearing Journal Clearance

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

Scheme 48

Scheme 49

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. If out of specification, install new components as necessary.

Scheme 50

Scheme 51

1. Inspect the roller for flat spots or scoring. If any damage is found, inspect the camshaft lobes and valve tappet for damage.

Scheme 52

Scheme 53

1. Inspect the hydraulic valve tappet and roller for damage. If any damage is found, inspect the camshaft lobes and valves for damage.

Scheme 54

Scheme 55

1. Compress the hydraulic valve tappet to remove the engine oil if necessary.
2. Place the (1) hydraulic valve tappet in a (2) commercially available hydraulic tappet leakdown tester. Position the (3) steel ball provided in the plunger cap. Add testing fluid to cover the hydraulic valve tappet and compress hydraulic tappet leakdown tester until the hydraulic valve tappet is filled with testing fluid.
3. Adjust the length of the (1) ram so the (2) pointer is just below the (3) Start Timing mark when the ram contacts the hydraulic valve tappet. Start timing as the pointer passes the (3) Start Timing mark and end timing as the pointer reaches the (4) center mark. See «GENERAL SPECIFICATIONS»(/ford/explorer-sport-trac/i-2000-2005/remont/mechanical/#engine-40l-sohc__general-specifications) in ENGINE article.

Scheme 56

1. Measure the diameter of each intake and exhaust valve stem at the points shown. Verify the diameter is within specification. See «GENERAL SPECIFICATIONS»(/ford/explorer-sport-trac/i-2000-2005/remont/mechanical/#engine-40l-sohc__general-specifications) in ENGINE article. If out of specification, install new components as necessary.

Scheme 57

Measuring Valve Stem-To-Valve Guide Clearance

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

1. Install a Valve Stem Clearance Tool on the valve stem and install a Dial Indicator with Bracketry. Lower the valve until the Valve Stem Clearance Tool contacts the upper surface of the valve guide.
2. Move the Valve Stem Clearance Tool toward the indicator and zero the indicator. Move the Valve Stem Clearance Tool away from the indicator and note the reading. The reading will be DOUBLE the valve stem-to-valve guide clearance. Valves with oversize stems will need to be installed if out of specification.

Scheme 58

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

Scheme 59

1. Measure the inner diameter of the valve guides in two directions where indicated.
2. If the valve guide is not within specifications, ream the valve guide and install a valve with an oversize stem or remove the valve guide and install a new valve guide.

Scheme 60

1. Use a hand-reaming kit to ream the valve guide.
2. Reface the valve seat.
3. Clean the sharp edges left by reaming.

Scheme 61

1. Measure the installed length of each valve spring. If out of specification, install new components.

Scheme 62

1. Measure the free length of each valve spring. If out of specification, install new components as necessary.

Scheme 63

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. Install a new valve spring if out of square.

Scheme 64

Scheme 65

1. Use a Valve/Clutch Spring Pressure Gauge to check the valve spring for correct strength at the specified valve spring length. If out of specification, install new components as necessary.

Valve & Seat Refacing Measurements

Scheme 66

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.

Scheme 67

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.

Scheme 68

1. Use the Valve Seat Runout Gauge to check valve seat runout.

Scheme 69

Scheme 70

1. Use a straight edge and a feeler gauge to inspect the cylinder head for flatness. If the cylinder head is distorted, install a new cylinder head.

Scheme 71

Scheme 72

1. Install and tighten all main bearing caps to specification.
2. Hone with the Engine Cylinder Hone Set, at a speed of 300-500 rpm and a hone grit of 180-220 to provide the desired cylinder bore surface finish of 18-38AA.

CYLINDER BORE - CLEANING

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 meeting Ford specification.

Scheme 73

Scheme 74

1. Use a straightedge and a feeler gauge to inspect the cylinder block for flatness. If the cylinder block is distorted, resurface the cylinder block within specification.

Scheme 75

Scheme 76

Scheme 77

1. Use a slide hammer or tools suitable to remove the cylinder block core plug.
2. Inspect the cylinder block plug bore for any damage that would interfere with the correct sealing of the plug. If the cylinder block plug bore is damaged, bore for the next oversize plug.
3. Coat the cylinder block core plug and bore lightly with Threadlock® 262 and install the cylinder block core plug.

Cup-Type

1. Use a tool suitable to seat the cup-type cylinder block core plug.

Expansion-Type

1. Use tool suitable to seat the expansion-type cylinder block core plug.

SPARK PLUG HOLE THREAD REPAIR

1. There is no authorized repair for spark plug hole threads. If the threads are damaged, install a new cylinder head.

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

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. Clean the 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. Clean the spark plug.
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 a white or light gray spots and with 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. Clean the spark plug.

Scheme 85

Scheme 86

1. Place a straight edge across the exhaust manifold flanges and check for warping with a feeler gauge.

Scheme 87

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

See also:
• GENERAL SPECIFICATIONS
• SYMPTOM CHART
• ENGINE OIL LEAKS