Abnormal Engine Noise

1. Engine knocking.
a. Ensure engine is thoroughly warmed up.
b. Check injection timing (refer to text under ``Engine'').
c. Check injection nozzles.
d. Check compression.
e. Check that fuel is the proper quality.
f. Readjust or replace injection pump.

2. Noise indicating gas leakage.
a. Check exhaust pipe for loose connections or leakage.
b. Check glow plug and nozzle installation.
c. Check cylinder head gasket for leakage.
d. Check, and if necessary, adjust valve clearances.
e. Check compression.

3. Continuous noise.
a. Check fan belt tension.
b. Check cooling fan for looseness.
c. Check water pump bearing.
d. Check alternator and vacuum pump operation.
e. Check, and if necessary, adjust valve clearances.