EA88009 · EA
ENGINE AND ENGINE COOLING:ENGINE Investigation
ANALYSIS:MANY OF THE REPORTS INDICATE THAT THE PLASTIC VALVE COVER OR THE\TV GASKETING MATERIAL LOSES ITS STRUCTURAL AND/OR SEALING INTEGRITY DUE TOTHE HIGH ENGINE TEMPERATURES ASSOCIATED WITH THE AMC 258 ENGINE.TESTINGPERFORMED BY A LOCAL FLEET CLEARLY DEMONSTRATED THAT UNDER NORMAL DRIVINGCONDITIONS, MOTOR OIL LEAKS IN THE VICINITY OF THE #3 OR #4 CYLINDERS (OVERTHE EXHAUST MANIFOLD) CAN RESULT IN A FIRE SERIOUS ENOUGH TO DESTROY AVEHICLE.AMC HAS ISSUED NUMEROUS TSB'S REGARDING THE PROPER/IMPROPER METHOD OF SEAL-ING THE VALVE COVER-HEAD INTERFACE.1981-84 AMC 6-CYLINDER ENGINES AREEQUIPPED WITH A PLASTIC VALVE COVER WHICH HAS 5 GUIDE PINS AND 2 FASTENERS.THE COVER USED IN LATER MODELS WAS RE-DESIGNED TO HAVE 5 ATTACHING POINTS,AND THIS NEW VALVE COVER CAN BE USED ON OLDER ENGINES BY MEANS OF AMODIFICATION KIT.AS EXPECTED, COMPLAINTS OF ENGINE FIRES IN 1985 MODELSDROPPED SIGNIFICANTLY, INDICATING THAT THE ADDITION OF THE NEW VALVE COVERMAY HAVE SOLVED THE PROBLEM.STATUS: IR TO THE MANUFACTURER SENT 12/1/87.PROPOSED ACTION: OPEN AN ENGINEERING ANALYSIS.===