TM 10-3930-653-14&P Condition Probable cause Corrective action Worn piston ring groove and ring Renew piston and piston ring Fatigue of valve oil seal lip Replace seal lip with a new one Worn valve stem Renew valve or guide OIL  LEVEL Inadequate quality of engine oil Use the designated oil Engine overheat Previously mentioned POOR FUEL ECONOMY See the explanation of the power decrease FUEL  SYSTEM Exceeding idling revolution Adjust It to the designated rpm Faulty acceleration recovery Adjust It Fuel leakage Repair or tighten the connection of fuel pipes TROUBLE IN OTHER FUNCTIONS Decreased oil pressure Inadequate oil quality Use the designated oil Overheat Previously mentioned Faulty function of oil pump regulator valve Disassemble oil pump and repair or renew it Functional deterioration of oil pump Repair or replace It with a new one, Blocked oil filter Renew It Increased clearance in various sliding parts Disassemble and replace the worn parts with new ones Blocked oil strainer Clean it Troubles In oil gauge pressure switch Replace it with a new one Excessive wear on the Oil pressure decreases Previously mentioned sliding parts Faulty quality or contamination of oil Change to the designated oil and change oil filter. Insufficient air cleaner. Check element Overheat or overcool Previously mentioned Improper fuel mixture Check the fuel system Scuffing of sliding Decrease in oil pressure Previously mentioned parts Insufficient clearances Readjust to the designated clearances Overheat Previously mentioned Improper fuel mixture. Check the fuel system 4 - 7