SEAL - CRANKSHAFT OIL - REAR
DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, camshaft bore cup plugs, oil
galley pipe plugs, oil filter runoff, and main bearing cap to cylinder block mating surfaces. See Engine, for
proper repair procedures of these items.
4. If no leaks are detected, pressurized the crankcase as outlined in the section, Inspection (Engine oil Leaks in
general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch forleakage. If a leak is detected between
the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged.
The seal area on the crankshaft could have minor nicks or scratches that canbe polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks or
scratches. The crankshaft seal flange is specially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING), under the Oil Leak row, for components inspections on possible
causes and corrections.
7. After the oil leak root cause and appropriate corrective action have been identified, (Refer to 9 - ENGINE/EN-
GINE BLOCK/CRANKSHAFT OIL SEAL - REAR - REMOVAL).
REMOVAL
NOTE: This procedure can be performed in vehi-
cle.
1. If being performed in vehicle, remove the transmis-
sion.
2. Remove the flexplate (Refer to 9 - ENGINE/EN-
GINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Spe-
cial Tool 8506 must be installed deeply into the
seal. Continue to tighten the removal tool into the
seal until the tool can not be turned farther. Fail-
ure to install tool correctly the first time will cause
tool to pull free of seal without removing seal from
engine.
RETAINER - CRANK REAR OIL - SEAL
REMOVAL
1. Disconnect negative cable from battery.
2. Remove the transmission. (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - NAG1 -
REMOVAL).
3. Remove the flexplate. (Refer to 9 - ENGINE/EN-
GINE BLOCK/FLEX PLATE - REMOVAL).
4. Remove the oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
5. Remove the rear oil seal retainer mounting bolts.
6. Carefully remove the retainer from the engine
block.
INSTALLATION
1. Throughly clean all gasket resdue from the engine
block.
2. Use extream care and clean all gasket resdue from
the retainer.
3. Position the gasket onto the retainer.
4. Position the retainer onto the engine block.
5. Install the retainer mounting bolts. Tighten the bolts
to 15 Nꞏm (132 in. lbs.) using the procedure shown.
6. Install the oil pan (Refer to 9 - ENGINE/LUBRICA-
TION/OIL PAN - INSTALLATION).
7. Install the flexplate (Refer to 9 - ENGINE/ENGINE
BLOCK/FLEX PLATE - INSTALLATION).
8. Install the transmission (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - NAG1 -
INSTALLATION).
9. Check and verify engine oil level.
10. Start engine and check for leaks.
TAPPETS - HYDRAULIC ROLLER
DIAGNOSIS AND TESTING - HYDRAULIC TAPPETS
Before disassembling any part of the engine to correct tappet noise, checkthe oil pressure. If vehicle has no oil
pressure gauge, install a reliable gauge at the pressure sending-unit. The pressure should be between 207-552 kPa
(30-70 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal operating temperature. Allow 5 minutes to stabilize oil level,
check dipstick. The oil level in the pan should never be above the FULL mark or below the ADD OIL mark on
dipstick. Either of these two conditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible for the connecting rods todip into the oil. With the engine running,
this condition could create foam in the oil pan. Foam in oil pan would be fed to the hydraulic tappets by the oil pump
causing them to lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air. When air is fed to the tappets,they lose length, which allows valves
to seat noisily. Any leaks on intake side of oil pump through which air can bedrawn will create the same tappet
action. Check the lubrication system from the intake strainer to the pump cover, including the relief valve retainer
cap. When tappet noise is due to aeration, it may be intermittent or constant, and usually more than one tappet will
be noisy. When oil level and leaks have been corrected, operate the engine at fast idle. Run engine for a sufficient
time to allow all of the air inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
1. To determine source of tappet noise, crank over engine with cylinder head covers removed.
2. Feel each valve spring or rocker arm to detect noisy tappet. The noisy tappet will cause the affected spring
and/or rocker arm to vibrate or feel rough in operation.
NOTE: Worn valve guides or cocked springs are sometimes mistaken for noisytappets. If such is the case,
noise may be dampened by applying side thrust on the valve spring. If noise is not appreciably reduced, it
can be assumed the noise is in the tappet. Inspect the rocker arm push rod sockets and push rod ends for
wear.
3. Valve tappet noise ranges from light noise to a heavy click. A light noiseis usually caused by excessive leak-
down around the unit plunger, or by the plunger partially sticking in the tappet body cylinder. The tappet should
be replaced. A heavy click is caused by a tappet check valve not seating, or by foreign particles wedged between
the plunger and the tappet body. This will cause the plunger to stick in the down position. This heavy click will be
accompanied by excessive clearance between the valve stem and rocker arm as valve closes. In either case,
tappet assembly should be removed for inspection and cleaning.
4. The valve train generates a noise very much like a light tappet noise during normal operation. Care must be
taken to ensure that tappets are making the noise. If more than one tappet seems to be noisy, it’s probably not
the tappets.
REMOVAL
1. Disconnect the negative cable from the battery.
2. Remove the air cleaner (Refer to 9 - ENGINE/AIR INTAKE SYSTEM - REMOVAL).
3. Remove intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD-REMOVAL).
4. Remove cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDERHEAD COVER(S) -
REMOVAL).
5. Remove rocker arm assembly and push rods (Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - REMOVAL). Identify push rods to ensure installation in original location.
6. Remove the cylinder head (Refer to 9 - ENGINE/CYLINDER HEAD - REMOVAL).
CAUTION: 5.7L engines equipped with MDS uses both standard roller tappetsand deactivating roller tap-
pets, for use with the Multi Displacement System. The deactivating rollertappets must be used in cylinders
1,4,6,7. The deactivating tappets can be identified by the two holes in theside of the tappet body, for the
latching pins.
2. Install tappets in their original positions.
3. Install tappet retainer (1). Install the tappet retainer bolt and tighten to 12 Nꞏm (106 in. lbs.) torque.
4. Install cylinder head (Refer to 9 - ENGINE/CYLINDER HEAD - INSTALLATION).
5. Install pushrods and rocker arm assembly (Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER ARM / ADJUSTER
ASSY - INSTALLATION).
6. Install cylinder head cover (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLA-
TION).
7. Install intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD-INSTALLATION).
8. Install the air cleaner (Refer to 9 - ENGINE/AIR INTAKE SYSTEM - INSTALLATION).
9. Connect the negative cable to the battery.
CAUTION: To prevent damage to valve mechanism, engine must not be run abovefast idle until all hydrau-
lic tappets have filled with oil and have become quiet.
10. Road test vehicle and check for leaks.
5. Remove connecting rod cap. Install Special Tool 8507 Connecting Rod Guides into the connecting rod being
removed. Remove piston from cylinder bore. Repeat this procedure for eachpiston being removed.
CAUTION: Care must be taken not to nick crankshaft journals, as engine damage may occur
6. Immediately after piston and connecting rod removal, install bearing cap on the mating connecting rod to prevent
damage to the fractured cap and rod surfaces.
7. Carefully remove piston rings from piston(s), starting from the top ring down.
CLEANING
CAUTION: DO NOT use a wire wheel or other abrasive cleaning devise to clean the pistons or connecting
rods. The pistons have a Moly coating, this coating must not be damaged.
1. Using a suitable cleaning solvent clean the pistons in warm water and towel dry.
2. Use a wood or plastic scraper to clean the ring land grooves.
CAUTION: DO NOT remove the piston pin from the piston and connecting rod assembly.
INSPECTION
Check the connecting rod journal for excessive wear, taper and scoring (Refer to 9 - ENGINE/ENGINE BLOCK/
CONNECTING ROD BEARINGS - STANDARD PROCEDURE).
Check the connecting rod for signs of twist or bending.
Check the piston for taper and elliptical shape before it is fitted into thecylinder bore (Refer to 9 - ENGINE/ENGINE
BLOCK/PISTON & CONNECTING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in the piston skirts. Checkthe ring lands for cracks and/or deteri-
oration.
LUBRICATION
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CHECKING ENGINE OIL PRESSURE
1. Remove oil pressure sending unit and install gauge assembly C-3292.
2. Run engine until thermostat opens.
3. Oil Pressure:
Curb Idle–25 kPa (4 psi) minimum
3000 rpm–170 - 758 kPa (25 - 110 psi)
4. If oil pressure is 0 at idle, shut off engine. Check for a clogged oil pick-up screen or a pressure relief valve stuck
open.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the engine, particularly at thearea of the suspected leak. If an oil leak
source is not readily identifiable, thefollowingstepsshouldbefollowed:
1. Do not clean or degrease the engine at this time because some solvents maycause rubber to swell, temporarily
stopping the leak.
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for approximately 15
minutes. Check the oil dipstick to make sure the dye is thoroughly mixed as indicated with a bright yellow color
under a black light.
3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If
the oil leak is found and identified, repair per service manual instructions.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.If the oil leak source is not positively identified at this time, proceed with the air leak detection test
method.
Air Leak Detection Test Method
1. Remove the PCV valve from the IAFM. Cap or plug the PCV valve grommet.
2. Attach an air hose with pressure gauge and regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 PSI) of test pressure.
3. Gradually apply air pressure from 1 psi to 2.5 psi maximum while applyingsoapy water at the suspected source.
Adjust the regulator to the suitable test pressure that provide the best bubbles which will pinpoint the leak
source. If the oil leak is detected and identified, repair per service manual procedures.
4. If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area Leak.
5. If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV
valve.
6. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx-
imately 24 km (15 miles). Inspect the engine for signs of an oil leak by usinga black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in therear seal area of the engine, a more
involved inspection is necessary. The following steps should be followedto help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light
to check for the oil leak:
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
OIL
STANDARD PROCEDURE - ENGINE OIL SERVICE
The engine oil level indicator is located at the left hand of the engine on the 5.7L engines.
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil, pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800 kilometers (500 miles).Unless the engine has exhibited loss of oil
pressure, run the engine for about ten minutes before checking oil level. Checking engine oil level on a cold engine
is not accurate.
To ensure proper lubrication of an engine, the engine oil must be maintained at an acceptable level. The acceptable
levels are indicated between the ADD and SAFE marks on the engine oil dipstick.
1. Position vehicle on level surface.
2. With engine OFF, allow approximately five minutes for oil to settle to bottom of crankcase, remove engine oil
dipstick.
3. Wipe dipstick clean.
4. Install dipstick and verify it is seated in the tube.
5. Remove dipstick, with handle held above the tip, take oil level reading.
6. Add oil only if level is below the ADD mark on dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals described in Maintenance Schedules (Refer to LUBRICATION &
MAINTENANCE/MAINTENANCESCHEDULES - DESCRIPTION).
Run engine until achieving normal operating temperature.
1. Position the vehicle on a level surface and turn engine off.
2. Hoist and support vehicle on safety stands.
3. Remove oil fill cap.
4. Place a suitable drain pan under crankcase drain.
5. Remove drain plug from crankcase and allow oil to drain into pan. Inspectdrain plug threads for stretching or
other damage. Replace drain plug if damaged.
6. Install drain plug in crankcase. Torque to 34 Nꞏm ( 25 ft. lbs.).
7. Lower vehicle and fill crankcase with specified type and amount of engine oil described in this section.
8. Install oil fill cap.
9. Start engine and inspect for leaks.
10. Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used engine oil after it has been drained from a vehicle engine. Refer to
the WARNING at beginning of this section.
PA N - E N G I N E O I L
REMOVAL
1. Disconnect the negative battery cable.
2. Install engine support fixture special tool # 8534.Do not raise engine at this time.
3.For 2WD vehicles,Remove both engine mount to frame through bolts.
4.For 4WD vehicles,Loosen both left and right side engine mount bracket to mount bolts, and remove the lower
bolt on each side. The upper hole in the engine bracket is slotted.
5. Remove the structural dust cover (1). (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCTURAL COVER -
REMOVAL)
6. Drain engine oil.
7. Remove the front crossmember (Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - REMOVAL).
CAUTION: Only raise the engine enough to pro-
vide clearance for oil pan removal. Check for
proper clearance at fan shroud to fan and cowl to
intake manifold.
8. Raise engine using special tool # 8534 to provide
clearance to remove oil pan.
9. Remove the nuts from the transmission mount to
crossmember.
10. Using suitable transmission jack, raise the trans-
mission approximately 3 inches off of the
crossmember.