5.7L Engine - Service Information: Diagnosis — 5.7L Engine - Service Information — Mechanical

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE

CONDITION	POSSIBLE CAUSE	CORRECTION
ENGINE WILL NOT START	Weak battery Corroded or loose battery connections. Faulty starter. Faulty coil or control unit. Incorrect spark plug gap. Dirt or water in fuel system. Faulty fuel pump, relay or wiring.	Charge or replace as necessary. Clean and tighten battery connections. Apply a coat of light mineral grease to the terminals. (Refer to STARTERS ). (Refer to COIL-IGNITION ). (Refer to CLEANING ). Clean system and replace fuel filter. Repair or replace as necessary.
ENGINE STALLS OR ROUGH IDLE	Idle speed set to low. Idle mixture too lean or too rich. Vacuum leak. Faulty coil. Incorrect engine timing.	(Refer to MOTOR-IDLE AIR CONTROL ). Refer to ENGINE ELECTRICAL DIAGNOSTICS . Inspect intake manifold and vacuum hoses, repair or replace as necessary. (Refer to COIL-IGNITION ). (Refer to STANDARD PROCEDURE ).
ENGINE LOSS OF POWER	Dirty or incorrectly gapped spark plugs. Dirt or water in fuel system. Faulty fuel pump. Blown cylinder head gasket. Low compression. Burned, warped or pitted valves. Plugged or restricted exhaust system. Faulty coil.	(Refer to CLEANING ). Clean system and replace fuel filter. Refer to PUMP-FUEL . Replace cylinder head gasket. (Refer to DIAGNOSIS AND TESTING )). Replace as necessary. Inspect and replace as necessary. (Refer to COIL-IGNITION ).
ENGINE MISSES ON ACCELERATION	Spark plugs dirty or incorrectly gapped. Dirt in fuel system. Burned, warped or pitted valves. Faulty coil.	(Refer to CLEANING ). Clean fuel system. Replcae as necessary. (Refer to COIL-IGNITION ).
ENGINE MISSES AT HIGH SPEED	Spark plugs dirty or incorrectly gapped. Faulty coil. Dirt or water in fuel system.	(Refer to CLEANING ). (Refer to COIL-IGNITION ). Clean system and replace fuel filter.

ENGINE DIAGNOSIS REFERENCE

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL

CONDITION	POSSIBLE CAUSES	CORRECTIONS
NOISY VALVES	High or low oil level in crankcase. Thin or diluted oil. Low oil pressure. Dirt in lash adjusters. Worn rocker arms. Worn lash adjusters Worn valve guides. Excessive runout of valve seats on valve faces.	(Refer to LUBRICATION ) Change oil and filter. Check oil pump, if Ok, check rod and main bearings for excessive wear. Replace as necessary. Replace as necessary. Replace as necessary. (Refer to STANDARD PROCEDURE ) (Refer to STANDARD PROCEDURE )
CONNECTING ROD NOISE	Insufficient oil supply. Low oil pressure. Thin or diluted oil. Excessive bearing clearance. Connecting rod journal out-of-round. Misaligned connecting rods.	(Refer to LUBRICATION ) Check oil pump, if Ok, check rod and main bearings for excessive wear. Change oil and filter. Replace as necessary. Service or replace crankshaft. Replace bent connecting rods.
MAIN BEARING NOISE	Insufficient oil supply. Low oil pressure. Thin or diluted oil. Excessive bearing clearance. Excessive end play. Crankshaft journal out-of round. Loose flywheel or torque converter.	(Refer to LUBRICATION ) Check oil pump, if Ok, check rod and main bearings for excessive wear. Change oil and filter. Replace as necessary. Check thrust washers for wear. Service or replace crankshaft. Tighten to correct torque

ENGINE DIAGNOSIS - MECHANICAL REFERENCE

DIAGNOSIS AND TESTING - CYLINDER COMPRESSION PRESSURE

The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.

Ensure the battery is completely charged and the engine starter motor is in good operating condition. Otherwise the indicated compression pressures may not be valid for diagnosis purposes.

Clean the spark plug recesses with compressed air.
Remove the spark plugs.
Disable the fuel system. Refer to «FUEL DELIVERY»(ref-564649) .
Remove the ASD relay (Refer to «RELAY-AUTO SHUT DOWN»(ref-238310-S01616294542006072400000) ).
Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders.
(Refer to «SPECIFICATIONS»(ref-212816-S32984530442005122700000) ) for the correct engine compression pressures.

DIAGNOSIS AND TESTING - CYLINDER COMBUSTION PRESSURE LEAKAGE

The combustion pressure leakage test provides an accurate means for determining engine condition.

Combustion pressure leakage testing will detect

Exhaust and intake valve leaks (improper seating).
Leaks between adjacent cylinders or into water jacket.
Any causes for combustion/compression pressure loss.

Check the coolant level and fill as required. DO NOT install the radiator cap.
Start and operate the engine until it attains normal operating temperature, then turn the engine OFF.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner hose.
Calibrate the tester according to the manufacturer's instructions. The shop air source for testing should maintain 483 kPa (70 psi) minimum, 1,379 kPa (200 psi) maximum and 552 kPa (80 psi) recommended.
Perform the test procedures on each cylinder according to the tester manufacturer's instructions. Set piston of cylinder to be tested at TDC compression, While testing, listen for pressurized air escaping through the throttle body, tailpipe and oil filler cap opening. Check for bubbles in the radiator coolant.

All gauge pressure indications should be equal, with no more than 25% leakage.

FOR EXAMPLE: At 552 kPa (80 psi) input pressure, a minimum of 414 kPa (60 psi) should be maintained in the cylinder.

Refer to CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART .

CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART

CONDITION	POSSIBLE CAUSE	CORRECTION
AIR ESCAPES THROUGH THROTTLE BODY	Intake valve bent, burnt, or not seated properly	Inspect valve and valve seat. Reface or replace, as necessary. Inspect valve springs. Replace as necessary.
AIR ESCAPES THROUGH TAILPIPE	Exhaust valve bent, burnt, or not seated properly	Inspect valve and valve seat. Reface or replace, as necessary. Inspect valve springs. Replace as necessary.
AIR ESCAPES THROUGH RADIATOR	Head gasket leaking or cracked cylinder head or block	Remove cylinder head and inspect. Replace defective part
MORE THAN 50% LEAKAGE FROM ADJACENT CYLINDERS	Head gasket leaking or crack in cylinder head or block between adjacent cylinders	Remove cylinder head and inspect. Replace gasket, head, or block as necessary
MORE THAN 25% LEAKAGE AND AIR ESCAPES THROUGH OIL FILLER CAP OPENING ONLY	Stuck or broken piston rings; cracked piston; worn rings and/or cylinder wall	Inspect for broken rings or piston. Measure ring gap and cylinder diameter, taper and out-of-round. Replace defective part as necessary

CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - LUBRICATION

CONDITION	POSSIBLE CAUSES	CORRECTION
OIL LEAKS	Gaskets and O-Rings. Misaligned or damaged. Loose fasteners, broken or porous metal parts. Crankshaft rear seal Crankshaft seal flange. Scratched, nicked or grooved. Oil pan flange cracked. Front cover seal, damaged or misaligned. Scratched or damaged vibration damper hub. Crankshaft Rear Flange Microporosity	Replace as necessary. Tighten fasteners, Repair or replace metal parts. Replace as necessary. Polish or replace crankshaft. Replace oil pan. Replace seal. Polish or replace damper. Replace Crankshaft
OIL PRESSURE DROP	Low oil level. Faulty oil pressure sending unit. Low oil pressure. Clogged oil filter. Worn oil pump. Thin or diluted oil. Excessive bearing clearance. Oil pump relief valve stuck. Oil pickup tube loose or damaged.	Check and correct oil level. Replace sending unit. Check pump and bearing clearance. Replace oil filter. Replace as necessary. Change oil and filter. Replace as necessary. Replace oil pump. Replace as necessary.
OIL PUMPING AT RINGS; SPARK PLUGS FOULING	Worn or damaged rings. Carbon in oil ring slots. Incorrect ring size installed. Worn valve guides. Leaking intake gasket. Leaking valve guide seals.	Hone cylinder bores and replace rings. Replace rings. Replace rings. Ream guides and replace valves. Replace intake gaskets. Replace valve guide seals.

ENGINE DIAGNOSIS - LUBRICATION

ENGINE MECHANICAL DIAGNOSIS CHART

CONDITION	POSSIBLE CAUSES	CORRECTION
NOISY VALVES/LIFTERS	High or low oil level in crankcase Thin or diluted oil Low oil pressure Dirt in tappets/lash adjusters Bent push rod(s) Worn rocker arms Worn tappets/lash adjusters Worn valve guides Excessive runout of valve seats or valve faces	Check for correct oil level. Adjust oil level by draining or adding as needed Change oil. (Refer to STANDARD PROCEDURE ) Check engine oil level. If ok, Perform oil pressure test. (Refer to DIAGNOSIS AND TESTING ) for engine oil pressure test/specifications Clean/replace hydraulic tappets/lash adjusters Install new push rods Inspect oil supply to rocker arms and replace worn arms as needed Install new hydraulic tappets/lash adjusters Inspect all valve guides and replace as necessary Grind valves and seats
CONNECTING ROD NOISE	Insufficient oil supply Low oil pressure Thin or diluted oil Excessive connecting rod bearing clearance Connecting rod journal out of round Misaligned connecting rods	Check engine oil level. Check engine oil level. If ok, Perform oil pressure test. (Refer to DIAGNOSIS AND TESTING ) engine oil pressure test/specifications Change oil to correct viscosity. (Refer to STANDARD PROCEDURE ) for correct procedure/engine oil specifications Measure bearings for correct clearance with plastigage. Repair as necessary Replace crankshaft or grind journals Replace bent connecting rods
MAIN BEARING NOISE	Insufficient oil supply Low oil pressure Thin or diluted oil Excessive main bearing clearance Excessive end play Crankshaft main journal out of round or worn Loose flywheel or torque converter	Check engine oil level. Check engine oil level. If ok, Perform oil pressure test. (Refer to DIAGNOSIS AND TESTING ) Change oil to correct viscosity. Measure bearings for correct clearance. Repair as necessary Check crankshaft thrust bearing for excessive wear on flanges Grind journals or replace crankshaft Inspect crankshaft, flexplate/flywheel and bolts for damage. Tighten to correct torque
LOW OIL PRESSURE	Low oil level Faulty oil pressure sending unit Clogged oil filter Worn oil pump Thin or diluted oil Excessive bearing clearance Oil pump relief valve stuck Oil pickup tube loose, broken, bent or clogged Oil pump cover warped or cracked	Check oil level and fill if necessary Install new sending unit Install new oil filter Replace oil pump assembly. Change oil to correct viscosity. Measure bearings for correct clearance Remove valve to inspect, clean and reinstall Inspect oil pickup tube and pump, and clean or replace if necessary Install new oil pump
OIL LEAKS	Misaligned or deteriorated gaskets Loose fastener, broken or porous metal part Front or rear crankshaft oil seal leaking Leaking oil gallery plug or cup plug	Replace gasket Tighten, repair or replace the part Replace seal Remove and reseal threaded plug. Replace cup style plug
EXCESSIVE OIL CONSUMPTION OR SPARK PLUGS OIL FOULED	CCV System malfunction Defective valve stem seal(s) Worn or broken piston rings Scuffed pistons/cylinder walls Carbon in oil control ring groove Worn valve guides Piston rings fitted too tightly in grooves	(Refer to EVAPORATIVE EMISSIONS ) for correct operation Repair or replace seal(s) Hone cylinder bores. Install new rings Hone cylinder bores and replace pistons as required Remove rings and de-carbon piston Inspect/replace valve guides as necessary Remove rings and check ring end gap and side clearance. Replace if necessary

ENGINE MECHANICAL DIAGNOSIS

DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET FAILURE

A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent water jacket.

Possible indications of the cylinder head gasket leaking between adjacent cylinders are: Loss of engine power Engine misfiring Poor fuel economy
Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are: Engine overheating Loss of coolant Excessive steam (white smoke) emitting from exhaust Coolant foaming

CYLINDER-TO-CYLINDER LEAKAGE TEST

To determine if an engine cylinder head gasket is leaking between adjacent cylinders, follow the procedures in DIAGNOSIS AND TESTING - CYLINDER COMPRESSION PRESSURE . An engine cylinder head gasket leaking between adjacent cylinders will result in approximately a 50-70% reduction in compression pressure.

CYLINDER-TO-WATER JACKET LEAKAGE TEST

WARNING

USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRESSURE CAP REMOVED.

VISUAL TEST METHOD

With the engine cool, remove the coolant pressure cap. Start the engine and allow it to warm up until thermostat opens.

If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.

CHEMICAL TEST METHOD

Combustion leaks into the cooling system can also be checked by using Bloc-Chek Kit C-3685-A or equivalent. Perform test following the procedures supplied with the tool kit.

INSPECTION

Inspect the cylinder head for out-of-flatness, using a straightedge and a feeler gauge. If tolerances exceed 0.0508 mm (0.002 in.) replace the cylinder head.
Inspect the valve seats for damage. Service the valve seats as necessary.
Inspect the valve guides for wear, cracks or looseness. If either condition exist, replace the cylinder head.
Inspect pushrods. Replace worn or bent pushrods.

Scheme 338

Scheme 338: INSTALLATION

Clean all surfaces of cylinder block and cylinder heads.
Clean cylinder block front and rear gasket surfaces using a suitable solvent. CAUTION: The head gaskets are not interchangeable between left and right sides. They are marked "L" and "R" to indicate left and right sides.
Position new cylinder head gaskets onto the cylinder block. CAUTION: The head gaskets are marked "TOP" to indicate which side goes up.
Position cylinder heads onto head gaskets and cylinder block.
Tighten the cylinder head bolts in three steps : Step 1- Snug tighten M12 cylinder head bolts, in sequence, to 34 N.m (25 ft. lbs.) and M8 bolts to 20 N.m (15 ft. lbs.) torque. Step 2- Tighten M12 cylinder head bolts, in sequence, to 54 N.m (40 ft. lbs.) and verify M8 bolts to 20 N.m (15 ft. lbs.) torque.. Step 3- Turn M12 cylinder head bolts, in sequence, 90 degrees and tighten M8 bolts to 34 N.m (25 ft. lbs.) torque.
Install push rods and rocker arm assemblies in their original position.
Install the intake manifold and throttle body assembly.
If required, adjust spark plugs to specifications. Install the plugs.
Connect the heater hoses.
Install the fuel supply line.
Install the generator and drive belt.
Install cylinder head covers (Refer to «INSTALLATION»(ref-212816-S04550456792005122700000) ).
Connect the evaporation control system.
Install the wiper module (Refer to «MODULE-WINDSHIELD WIPER»(ref-212806-S16497299482005122700000) ).
Install the air cleaner.
Fill cooling system.
Connect the negative cable to the battery.
Start engine check for leaks.

The cam bearings are not serviceable. Do not attempt to replace cam bearings for any reason.

Wipe the inserts clean and inspect for abnormal wear patterns and for metal or other foreign material imbedded in the lining. Normal main bearing insert wear patterns are illustrated.

Note. If any of the crankshaft journals are scored, the crankshaft must be repaired or replaced.

Inspect the back of the inserts for fractures, scrapings or irregular wear patterns.

Inspect the upper insert locking tabs for damage.

Replace all damaged or worn bearing inserts.

Scheme 339

Scheme 339: INSPECTION

DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS

Since it is sometimes difficult to determine the source of an oil leak in the rear seal area of the engine, a more involved inspection is necessary. The following steps should be followed to help pinpoint the source of the leak.

If the leakage occurs at the crankshaft rear oil seal area

Disconnect the battery.
Raise the vehicle.
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: Circular spray pattern generally indicates seal leakage or crankshaft damage. 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.
If no leaks are detected, pressurize the crankcase as outlined in «Air Leak Detection Test Method»(ref-212816-S18191719092005122700000) CAUTION: Do not exceed 20.6 kPa (3 psi).
If the leak is not detected, very slowly turn the crankshaft and watch for leakage. 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 can be 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.
For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled. (Refer to «DIAGNOSIS AND TESTING»(ref-212816-S26973210812005122700000) )), under the Oil Leak row, for components inspections on possible causes and corrections.
After the oil leak root cause and appropriate corrective action have been identified, (Refer to «REMOVAL»(ref-212816-S33980703632005122700000) ).

DIAGNOSIS AND TESTING - HYDRAULIC TAPPETS

Before disassembling any part of the engine to correct tappet noise, check the 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.

TAPPET NOISE DIAGNOSIS

To determine source of tappet noise, operate engine at idle with cylinder head covers removed.
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 noisy tappets. 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.
Valve tappet noise ranges from light noise to a heavy click. A light noise is 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.
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.

Check the connecting rod journal for excessive wear, taper and scoring (Refer to INSPECTION ).

Check the connecting rod for signs of twist or bending.

Check the piston for taper and elliptical shape before it is fitted into the cylinder bore (Refer to STANDARD PROCEDURE ).

Check the piston for scoring, or scraping marks in the piston skirts. Check the ring lands for cracks and/or deterioration.

DIAGNOSIS AND TESTING - CHECKING ENGINE OIL PRESSURE

Remove oil pressure sending unit and install gauge assembly C-3292.
Run engine until thermostat opens.
Oil Pressure: Curb Idle-25 kPa (4 psi) minimum 3000 rpm-170 - 758 kPa (25-110 psi)
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 the area of the suspected leak. If an oil leak source is not readily identifiable, the following steps should be followed

Do not clean or degrease the engine at this time because some solvents may cause rubber to swell, temporarily stopping the leak.
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.
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.
If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspection. 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

Remove the PCV valve from the IAFM. Cap or plug the PCV valve grommet.
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.
Gradually apply air pressure from 1 psi to 2.5 psi maximum while applying soapy 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.
If the leakage occurs at the rear oil seal area, refer to «REAR SEAL AREA LEAK»(ref-212816-S12072798572005122700000) .
If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV valve.
Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approximately 24 km (15 miles). Inspect the engine for signs of an oil leak by using a black light.

INSPECTION FOR REAR SEAL AREA LEAKS

If the leakage occurs at the crankshaft rear oil seal area

Disconnect the battery.
Raise the vehicle.
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: Circular spray pattern generally indicates seal leakage or crankshaft damage. Where leakage tends to run straight down, possible causes are a porous block, distributor seal, camshaft bore cup plugs oil galley pipe plugs, oil filter runoff, and main bearing cap to cylinder block mating surfaces.
If no leaks are detected, pressurize the crankcase as outlined in «Air Leak Detection Test Method»(ref-212816-S18191719092005122700000) . CAUTION: Do not exceed 20.6 kPa (3 psi).
If the leak is not detected, very slowly turn the crankshaft and watch for leakage. 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 can be polished out with emery cloth. CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and scratches. The crankshaft seal flange is especially machined to complement the function of the rear oil seal.
For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled.

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.

Position vehicle on level surface.
With engine OFF, allow approximately five minutes for oil to settle to bottom of crankcase, remove engine oil dipstick.
Wipe dipstick clean.
Install dipstick and verify it is seated in the tube.
Remove dipstick, with handle held above the tip, take oil level reading.
Add oil only if level is below the ADD mark on dipstick.

CAUTION

Oil pump pressure relief valve and spring should not be removed from the oil pump. If these components are disassembled and or removed from the pump the entire oil pump assembly must be replaced.

Scheme 340

Scheme 341

Scheme 342

Remove the pump cover.
Clean all parts thoroughly. Mating surface of the oil pump housing should be smooth. If the pump cover is scratched or grooved the oil pump assembly should be replaced.
Slide outer rotor into the body of the oil pump. Press the outer rotor to one side of the oil pump body and measure clearance between the outer rotor and the body. If the measurement is 0.235mm (0.009 in.) or more the oil pump assembly must be replaced.
Install the inner rotor in the into the oil pump body. Measure the clearance between the inner and outer rotors, if the clearance between the rotors is .150 mm (0.006 in.) or more the oil pump assembly must be replaced.
Place a straight edge across the body of the oil pump (between the bolt holes), if a feeler gauge of .095 mm (0.0038 in.) or greater can be inserted between the straightedge and the rotors, the pump must be replaced.
Reinstall the pump cover. Torque fasteners to 15 N.m (132 in. lbs.).

Note. The 5.7 Oil pump is released as an assembly. There are no DaimlerChrysler part numbers for Sub-Assembly components. In the event the oil pump is not functioning or out of specification it must be replaced as an assembly.

DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKAGE

An intake manifold air leak is characterized by lower than normal manifold vacuum. Also, one or more cylinders may not be functioning.