ARMY TM 9-2815-259-24 AIR FORCE TO 38G1-125-2 MARINE CORPS 09249A/09246A-24 4-12 TABLE 4-1.  DIRECT SUPPORT TROUBLESHOOTING (Sheet 11 of 12) OK Not  OK OK OK Not  OK ENGINE KNOCKS Engine knocks. Check fuel injection pump timing (refer to paragraph 5.3.1). Perform end item troubleshooting procedures (refer to TM 9-6115-671-14 or other applicable TM). Check for dirty, defective, or leaking fuel injection nozzles (refer to paragraph 3.12.6). Not  OK OK Adjust fuel injection pump timing (refer to paragraph 5.3.1). Clean or replace fuel injection nozzles (refer to paragraph 4.6.2). Test for low engine compression (refer to paragraph 3.7.1). Check for worn or stuck valves (refer to paragraph 4.7.4). Notify next higher level of maintenance. Repair/Replace valve seats/valves (refer to paragraph 4.7.4). Notify next higher level of maintenance. Not  OK Did Oil Pressure Increase? Replace Engine. Yes No