B3.9 and B5.9 Series Engines
Valve Guide Seal, Cylinder Head (002-016)
Section 2 - Cylinder Head - Group 02
Engine Noise Diagnostic Procedures -
General Information (002-004-331)
Engine Noise Diagnostics
The sound emitted from the overhead can indicate a valve
train problem. Loose rocker levers will clatter. A sqeaking
noise can mean lack of lubrication for the adjusting screw
and the pushrod socket.
Valve leakage is often audible from the intake and exhaust
If the compression is low on one or more nonadjacent
cylinders and the pressure can not be increased by oiling
the rings, improper valve sealing is to be suspected.
Valve Guide Seal, Cylinder Head
Initial Check (002-016-001)
Valve Seal - Wear
Worn valve seals are typically detected by excessive smoke
at idle or when the engine is unloaded when the vehicle is
going downhill. Verify the condition by removing the valve
spring and inspecting the valve seals.