ARMY TM 9-2815-257-24 AIR FORCE TO 38G1-128-2 MARINE CORPS TM 10155A/2815-24/3 5-6 Table 5-2.  General Support Level Troubleshooting (continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 5. LOW COMPRESSION PRESSURE a.    Check for leak at inlet and exhaust valves indicating worn valve seat or guide (Para. 5-11). Remove and replace inlet / exhaust valve components as required (Para. 5-11). b. Check for loose cylinder head nuts causing leak at cylinder head gasket. Tighten cylinder head nuts in an even pattern to 30 to 33 ft-lbs (420 to 460 kg-cm). c. Check for broken or damaged cylinder head gasket (Para. 5-11). Remove and replace cylinder head gasket (Para. 5-11). 6. ENGINE EMITS WHITE SMOKE a. Possible worn or broken piston ring, worn piston.  Inspect piston assembly (Para. 5-10). Remove and replace damaged piston assembly components (Para. 5-10). b. Check for defective valve stem seal (Para. 5-11). Remove and replace valve stem seal (Para. 5-11). 7. ENGINE EMITS BLACK SMOKE a. Possible piston / cylinder liner seizure.  Inspect for seized components (Para. 5-10). Remove and replace damaged piston assembly components (Para. 5-10).