COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester’s pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
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.
LASH ADJUSTER (TAPPET) NOISE DIAGNOSIS
Proper noise diagnosis is essential in locating the
source of a NVH complaint. Locating a lash adjuster
(tappet) type noise can sometimes be difficult. As a
result, an initial misdiagnosis may occur.
Refer to the following chart indicating possible lash
adjuster (tappet) noise sources and possible sources
that could lead to a misdiagnosis.
Refer to Lash Adjuster (Tappet) Noise Chart for
Possible Causes and Correction of a lash adjuster
(tappet) type noise.
POSSIBLE NOISE SOURCES POSSIBLE NOISE MISDIAGNOSIS SOURCES
Spongy/soft/aerated lash adjusters. SRV valve axle chatter.
Missing lash adjuster swivel contact pads. Exhaust rocker arm-to-cylinder head cover contact.
Intake rocker-to-camshaft bearing journal contact. Piston pin bore fit.
Rocker arm bind-up. Timing drive hydraulic tensioner tick.
Intake rocker arm-to-spark plug tube contact. Accessory drive belt deterioration.
Excessive cam end play. Piston-to-bore clearance knock.
Broken valve spring. Crankshaft bearing noise.
Broken/loose camshaft sprocket bolt.
Incomplete cam lobe machining.
Cracked lash adjuster cartridge body.
9 - 88 3.2/3.5L ENGINE LH
DIAGNOSIS AND TESTING (Continued)
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