
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).

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.

INSPECTION—PUSHRODS
Inspect the pushrod ball and socket for signs of scor-
ing. Check for cracks where the ball and the socket
are pressed into the tube.
Roll the pushrod on a flat work surface with the socket
end hanging off the edge. Replace any pushrod that
appears to be bent.
INSTALLATION
WARNING: THE OUTSIDE EDGE OF THE HEAD
GASKET IS VERY SHARP. WHEN HANDLING THE
NEW HEAD GASKET, USE CARE NOT TO INJURE
YOURSELF.
1. Install a new gasket with the part number side up,
and locate the gasket over the dowel sleeves.
2. Using an engine lifting crane, lower the cylinder
head onto the engine.
3. Lightly lubricate head bolts under bolt head and on
threads, with engine oil and install. Using the
sequence shown , tighten bolts in the following
steps:
a. Torqueboltsto70Nꞏm(52ft.lbs.).
b. Back off 360 degrees in sequence.
c. Torque bolts to 105 Nꞏm (77 ft. lbs.).
d. Re-check all bolts to 105 Nꞏm (77 ft. lbs.).
e. Tighten all bolts an additional
1⁄4turn (90°).

6. Use a drill, a fine grit Flex-hone and a mixture of
equal parts of mineral spirits and SAE 30W engine
oil to de-glaze the bores.
7. The crosshatch angle is a function of drill speed
and how fast the hone is moved vertically.
8. Vertical strokes MUST be smooth continuous
passes along the full length of the bore.
9. Inspect the bore after 10 strokes.
10. Use a strong solution of hot water and laundry
detergent to clean the bores. Clean the cylinder
bores immediately after de-glazing.
11. Rinse the bores until the detergent is removed
and blow the block dry with compressed air.
12. Check the bore cleanliness by wiping with a
white, lint free, lightly oiled cloth. If grit residue is still present, repeat the cleaning process until all residue is
removed. Wash the bores and the complete block assembly with solvent and dry with compressed air. Place a
clean shop towel around the top main bearing saddle to deflect water and residue from piston cooling nozzels.
Remove directed piston cooling nozzles if installed.
13. Be sure to remove the tape covering the lube holes, rod journals, and piston cooling nozzles after the cleaning
process is complete.
STANDARD PROCEDURE—CYLINDER BORE REPAIR
Cylinder bore(s) can be repaired by one of two methods:
Method 1:—Over boring and using oversize pistons and rings.
Method 2:—Boring and installing a repair sleeve to return the bore to standard dimensions.
METHOD 1—OVERSIZE BORE
Cylinder bore(s) can be repaired by one of two methods:
Oversize pistons and rings are available in two sizes - 0.50 mm (0.0197 inch) and 1.00 mm (0.0393 inch).
Any combination of standard, 0.50 mm (0.0197 inch) or 1.00 mm (0.0393 inch)overbore may be used in the same
engine.
If more than 1.00 mm (0.0393 inch) overbore is needed, a repair sleeve can beinstalled (refer to Method 2—Repair
Sleeve).
Cylinder block bores may be bored twice before use of a repair sleeve is required. The first bore is 0.50 mm
(0.0197 inch) oversize. The second bore is 1.00 mm (0.0393 inch) oversize.
After boring to size, use a honing stone to chamfer the edge of the bore.
CYLINDER BORE DIMENSION CHART
DESCRIPTION MEASUREMENT
BORING DIAMETER DIMENSION 1st. REBORE - 102.469 mm (4.0342 in.)
2nd. REBORE - 102.969 mm (4.0539 in.)
HONING DIAMETER DIMENSIONS STANDARD - 102.020 ± 0.020 mm (4.0165 ± 0.0008
in.)
1st. REBORE - 102.520 ± 0.020 mm (4.0362 ± 0.0008
in.)
2nd. REBORE - 103.020 ± 0.020 mm 4.0559 ± 0.0008
in.)
CHAMFER DIMENSIONS Approx. 1.25 mm (0.049 in.) by 30°

PA N - E N G I N E O I L
REMOVAL
1. Disconnect the battery negative cables.
2. Install engine support fixture # 8534.
3. Raise vehicle on hoist.
4. Disconnect starter cables from starter motor.
5. Remove transmission and transfer case (if equipped).
6. Remove flywheel or flexplate.
7. Remove starter motor (Refer to 8 - ELECTRICAL/STARTING/STARTER MOTOR -REMOVAL) and transmission
adapter plate assembly.
WARNING: HOT OIL CAN CAUSE PERSONAL INJURY.
8. Drain the engine oil (Refer to 9 - ENGINE/LUBRICATION/OIL - STANDARD PROCEDURE).
9. Install the oil pan drain plug if sealing surface is not damaged and tighten to 50 Nꞏm (37 ft. lbs.) torque.
10. Remove oil pan bolts, break the pan to block seal, and lower pan slightlyandremoveoilsuctiontubefasteners.
11. Remove oil pan and suction tube.
CLEANING
Remove all gasket material from the oil pan and cylinder block sealing surfaces. Extra effort may be required
around T-joint areas. Clean oil pan and flush suction tube with a suitable solvent.
INSPECTION
Inspect the oil pan, suction tube, and tube braces for cracks and damage. Replace any defective component.
Inspect the oil drain plug and drain hole threads. Inspect the oil pan sealing surface for straightness. Repair any
minor imperfections with a ball-peen hammer. Do not attempt to repair an oil pan by welding.
INSTALLATION
1. Fill the T-joint between the pan rail/gear housing and pan rail/rear seal retainer with sealant. Use MoparSilicone
Rubber Adhesive Sealant or equivalent.
2. Place suction tube in oil pan and guide them into place. Slide oil pan gasket into postion.Using a new tube to
block gasket, install and tighten the suction tube bolts by hand. Startingwith the oil pump inlet bolts, tighten the
bolts to 24 Nꞏm (18 ft. lbs.) torque. Tighten the remaining tube brace boltsto 43 Nꞏm (32 ft. lbs.) torque.
3. Starting in the center and working outward, tighten the oil pan bolts to 28Nꞏm(21ft.lbs.)torque.
4. Install the flywheel housing assembly with the starter motor attached and tighten bolts to 77 Nꞏm (57 ft. lbs.)
torque.
5. Connect starter motor cables.
NOTE: A new clamping ring must be used on early or late builds, automatic or manual. Do not reuse clamp-
ing ring.
6. Install the flywheel to crankshaft adapter. Torque to 137 Nꞏm (101 ft. lbs.).
7. Install transmission and transfer case (if equipped).
8. Lower vehicle.
9. Remove the engine support fixture # 8534.
10. Install battery negative cables.
11. Fill the crankcase with new engine oil.
12. Start engine and check for leaks. Stop engine, check oil level, and adjust, if necessary.

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.
HYDRAULIC TAPPET NOISE DIAGNOSIS
PRELIMINARY STEP TO CHECKING THE HYDRAULIC TAPPETS
Before disassembling any part of the engine to correct tappet noise, checkengine oil level and oil pressure.
1. Check the engine oil level.
Oil Level Check: stop engine after reaching normal operating temperature
The oil level should never be above the FULL mark on dipstick, or below the ADD mark. Either of
these two conditions could be responsible for noisy tappets. Allow 5 minutes to stabilize oil level,
check dipstick.
2. Remove oil pressure sensor.
3. Install a reliable oil pressure gauge at oil pressure sensor location.
The oil pressure should be 206.8 - 551.6 kPa (30 - 80 psi) at 2000 rpm.
OIL LEVEL TOO HIGH
If oil level is above the FULL mark on dipstick, it is possible for the connecting rods to dip into the oil while engine
is running and create foam. Foam in oil pan would be fed to the hydraulic tappets by the oil pump causing them to
become soft and allow valves to seat noisily.
OIL LEVEL TOO LOW
Low oil level may allow pump to take in air which when fed to the tappets, causes them to become soft and allows
valves to seat noisily. Any leaks on intake side of pump through which air canbedrawnwillcreatethesametappet
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, engine should be operated at fast idle to allow all of the air
inside of the tappets to be bled out.
VALVE TRAIN NOISE DIAGNOSIS
To determine source of valve train noise, operate engine at idle with cylinder head covers removed and listen for
source of the noise.
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.
Valve tappet noise ranges from light noise to a heavy click. A light noise isusually caused by excessive leak-down
around the unit plunger which will necessitate replacing the tappet, or bythe plunger partially sticking in the tappet
body cylinder. A heavy click is caused either by a tappet check valve not seating, or by foreign particles becoming
wedged between the plunger and the tappet body causing the plunger to stickin 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 and replaced.
ENGINE OIL LEAK INSPECTION
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 as necessary.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.
5.If the oil leak source is not positively identified at this time, proceed with the air leak detection test method
as follows:
1. Disconnect the PCV hoses at the cylinder head covers and plug or cap the outlet on the covers.
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 6.89 kPa (1 psi) to 17.23 kPa (2.5 psi) maximum while applying soapy water
at the suspected source. Adjust the regulator to the suitable test pressure that provides 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 crankshaft rear oil seal area, refer to the section, Inspection for Rear Seal Area
Leak.
6. If no leaks are detected, turn off the air supply. Remove the air hose, allplugs, and caps. Connect the PCV
hoses. Proceed to next step.
7. 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.
NOTE: If oil leakage is observed at the dipstick tube to oil pan location; remove the tube, clean and reseal
using Mopar
Stud & Bearing Mount (press fit tube applications only), and for O-ring style tubes, remove
tube and replace the O-ring seal.
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 clutch housing inspection cover and inspect rear of block for evidence of oil. Use a black light to check
for the oil leak. If a leak is present in this area, remove transmission for further inspection.
a. Circular spray pattern generally indicates seal leakage or crankshaftdamage.
b. Where leakage tends to run straight down, possible causes are a porous block, oil gallery cup plug or rear
crankshaft seal retainer gasket leak. See proper repair procedures for these items.
4. If no leaks are detected, pressurize the crankcase as previously described.
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 and
scratches. The crankshaft seal flange is especially 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.
7. After the oil leak root cause and appropriate corrective action have been identified, replace component(s) as
necessary.

CLEANING
CLEANING AND INSPECTION
1. Before cleaning, check for leaks, damage and
cracks.
2. Clean cylinder head and oil passages.
3. Check cylinder head for flatness.
4. Inspect all surfaces with a straightedge (2) if there
is any reason to suspect leakage. If out-of-flatness
exceeds 0.019 mm (0.00075 in.) times the span
length in inches in any direction, either replace
head or lightly machine the head surface. As an
example, if a 12.0 inch span is 1.0 mm (0.004 in.)
out-of-flat, allowable is 12 x 0.019 mm (0.00075 in.)
equals 0.22 mm (0.009 in.). This amount of out-of-
flat is acceptable. *Maximum of 0.2 mm (0.008 in.)
for grinding is permitted.
CAUTION: This is a combined total dimension of
stock removal from cylinder head surface.
INSTALLATION - CYLINDER HEAD(S)
NOTE: This procedure covers either the left or
right cylinder head.
1. Clean all surfaces of engine block and cylinder
heads (Refer to 9 - ENGINE - STANDARD PRO-
CEDURE - ENGINE GASKET SURFACE PREPA-
RATION).
CAUTION: Remove all gasket material from cylin-
der head and block using a plastic scraper only.
DO NOT use a metal scraper, as damage to seal-
ing surface may occur.
NOTE: A multi-layer steel head gasket is used.
2. Install new gasket(s) on the engine block. Assure all coolant passages and bolt holes align properly..
CAUTION: Cylinder head bolts are coated, DO NOT
oil.
3. Install cylinder head(s) over dowel pins. Install cyl-
inder head bolts 1–12. Tighten cylinder head bolts
1–12 in the sequence shown in using a two step
torque sequence:
a. Firstto47Nꞏm(35ft.lbs.).
b. Second to 122 Nꞏm (90 ft. lbs.).
4. After cylinder head bolts 1-12 have been tightened
to specifications, install and tighten cylinder head tappet gallery bolts A-H in sequence shown to 11 Nꞏm (95 in.
lbs.).