TROUBLESHOOTING SERVICE MANUAL NUMBER 22
Page 1C-20 90-860074--1 FEBRUARY 2002
Valve Cover Area
Location Possible Cause
1. Valve cover area, timed to one-half
engine speed, noise could be confined to
one cylinder or may be found in any
multitude of cylinders
1. A. Rocker arm striking valve cover
B. Hydraulic lifter
C. Worn rocker arm
D. Bent push rod
E. Worn camshaft
F. Sticking valve
Cylinder Area
Location Possible Causes
1. Cylinder area, may be confined to one
cylinder or found in more than one
cylinder, timed to engine speed
1. A. Sticking valve
B. Carbon build-up
C. Connecting rod installed wrong
D. Bent connecting rod
E. Piston
F. Piston rings
G. Piston pin
H. Cylinder worn
2. Engine knocking 2. A. Faulty injector (white smoke)
B. Worn delivery valve
C. Wrong injection timing
D. Incorrect valve lifter
E. Tight piston pin