GM S10/S15/Sonoma Pick-Ups 1982-1993 Repair Manual

Knocking Valves


When the valves are constantly noisy, check for the following, as necessary:

Unadjusted valve lash.
Valve springs may be broken.
Pushrods may be bent.
Camshaft lobes may be excessively worn.
Dirty or worn valve lifters.
Valve guides may be worn.
Valve seat or face runout may be excessive.
Loose rocker arm studs.