LASH ADJUSTER (TAPPET) NOISE CHART
POSSIBLE CAUSES CORRECTION
1. Engine oil level—too high or too low. This may cause
aerated oil to enter the adjusters and cause them to be
spongy.
1. Check and correct engine oil level.
2. Insufficient running time after rebuilding cylinder
head.
2. Low speed running of up to 1 hour may be required
to fully evacuate trapped air from the valve train
system. During this time, turn engine off and let set for
a few minutes before restarting. Repeat this several
times after engine has reached normal operating
temperature.
3. Air trapped in lash adjuster (after 1 hour run time). 3. See below:
(a) Check lash adjusters for sponginess while installed
in cylinder head. Depress part of rocker arm over
adjuster. Normal adjusters should feel very firm. Very
spongy adjusters can be bottomed out easily.
(b) Before proceeding, perform Lash Adjuster Bleeding
procedure.
(c) If lash adjuster(s) are still spongy, replace with new
adjuster/rocker arm assembly*.
4. Low oil pressure 4. See below:
(a) Check and correct engine oil level.
(b) Check engine oil pressure.
(c) Check for excessive bearing clearance and correct.
(d) Check for worn oil pump.
5. Oil passage to cylinder head(s) plugged with debris. 5. Check cylinder head oil passages and cylinder head
gasket restrictor for blockage. Clean or replace as
necessary.
6. Worn valve guide(s). 6. Ream guide(s) and replace valve(s) with oversize
valves and seal(s).
7. Air injested into oil due to broken or cracked oil
pump pickup tube.
7. Inspect pickup tube and replace as necessary.
8. Collapsed lash adjuster due to debris injestion. 8. Clean debris from engine and replace lash
adjuster/rocker assembly*.
9. Intake rocker arm roller clevis ear(s) contacting
camshaft bearing journal(s) on side.
9. Inspect camshaft end play and all valve train
components for wear. Replace as necessary.
*3.2/3.5L engine lash adjusters are serviced with the rocker arms—do not disassemble.
ENGINE OIL LEAK INSPECTION
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:
(1) Do not clean or degrease the engine at this
time because some solvents may cause 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 var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
LH 3.2/3.5L ENGINE 9 - 89
DIAGNOSIS AND TESTING (Continued)
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