TM 5-3805-261-34
ENGINE TROUBLESHOOTING AND MAINTENANCE PROCEDURES.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
f.
TOO MUCH VIBRATION.
Step 3.
Check the engine supports.
If the engine mounting or hardware is damaged or defective--replace. Refer to paragraph 3-5.
Step 4.
Check balancer shafts for proper installation.
If balancer shafts are damaged or defective--replace. Refer to paragraph 13-6.
g.
LOUD COMBUSTION NOISE (KNOCK) IN ENGINE.
WARNING
FUEL UNDER PRESSURE
When opening fuel system, do not look directly at fitting. Fuel is under high pressure.
SEVERE INJURY may result if you fail to follow this procedure.
Step 1.
Check the fuel injection valves and pumps. Run the engine at an RPM that causes the most noise.
Loosen a fuel line nut on the injection valve of each cylinder one at a time, then tighten. If loosening a
fuel line nut does not make a difference—replace injection valve. Refer to paragraph 3-25.
Step 2.
Check the fuel injection timing.
If the timing is not correct--adjust. Refer to paragraph 3-27.
h.
CLICKING NOISE IN VALVE COMPARTMENT.
Step 1.
Check the valve springs and locks.
If the valve springs or locks are damaged or defective--replace. Refer to paragraph 3-13.
Step 2.
Check the lubrication in the valve compartment. There must be a strong flow of oil at a high RPM and
a small flow at a low RPM.
If the oil level is not correct--service. Refer to paragraph 3-13.
Step 3.
Check the valve clearance.
If the valve clearance is too much--adjust. Refer to paragraph 3-12.
3-7
