ENGINE MECHANICAL ITEMS QUICK SERVICE INFORMATION

THIS BULLETIN CONTAINS MULTIPLE SUBJECTS. PAGE THROUGH TO DESIRED SUBECT.

GR. 6A NYLON ROCKER ARM COVER MOUNTING SCREW/STUD TORQUE SPECIFICATION

WHEN SERVICING ALL 1980-81 CADILLAC ENGINES EQUIPPED WITH NYLON ROCKER ARM COVERS, THE NINE ROCKER ARM COVER MOUNTING SCREWS/STUDS SHOULD BE INSTALLED AND TIGHTENED TO 8.0 N.M (71 IN. LBS.). THIS SUPERSEDES THE TORQUE SPECIFICATION PRINTED IN PREVIOUS SERVICE PUBLICATIONS AS WELL AS THE 1981 SERVICE INFORMATION MANUAL.

GR. 6A 1981 V-8 GAS ENGINE OIL PAN LEAK CORRECTION

SOME 1981 V-8 ENGINES MIGHT EXHIBIT AN OIL PAN LEAK AT THE SECOND OIL PAN BOLT FROM FRONT OF ENGINE, ON THE 1H SIDE. THE HOLE FOR THE BOLT IN THE BLOCK MAY HAVE BEEN DRILLED THROUGH INTO THE CRANKCASE. LEAK CAN BE CORRECTED BY REMOVING BOLT, CLEANING BOLT AND HOLE, COATING BOLT WITH RTV AND REINSTALLING.

GR.6A MODULATED DISPLACEMENT ENGINES REQUIRE SPECIFIC ENGINE MOUNTS

1981 MODULATED DISPLACEMENT ENGINES REQUIRE SPECIFIC ENGINE MOUNTS. IN THE CASE OF "E" AND "K" CARS, AN ASSYMETRIC MOUNTING SYSTEM WAS DESIGNED WITH SPECIFIC RATE MOUNTS ON EACH SIDE. IF THESE MOUNTS ARE REVERSED, THE VEHICLE IMPACT FEEL WILL BECOME UNDULY HARSH DUE TO THE CHANGES IN VEHICLE STRUCTURE. CORRECT ORIENTATION FOR THE MOUNTS IS: LEFT SIDE - BLACK MOUNT #1620154; RIGHT SIDE - YELLOW MOUNT #1620155.

GR. 6A ENGINE OIL PUMP HOUSING MACHINING CAN AFFECT HIGH OIL PRESSURE - 6.0L

SOME EARLY 1981 6.0 LITER ENGINES WERE BUILT WITH MISMACHINED OIL PUMP HOUSINGS. THESE HOUSINGS COULD CAUSE HIGHER THAN NORMAL ENGINE OIL PRESSURES CAUSING OIL LEAK AT THE FILTER. CORRECT BY REPLACING OIL PUMP HOUSING.

GR. 6A ENGINE VALVE COVER REMOVAL -1981 C-CAR WITH DFI

THE RIGHT VALVE COVER ON 1981 C-CARS EQUIPPED WITH A DFI ENGINE CAN BE REMOVED MORE READILY IF THE THREADED FITTING AT THE CHECK VALVE ON THE AIR PIPE TO THE CATALYTIC CONVERTER IS LOOSENED, ALLOWING THE RUBBER AIR LINE TO BE MOVED AWAY FROM THE VALVE COVER. REMOVE THE VALVE COVER BY LIFTING THE REAR FIRST AND CLEARING THE HEATER CORE. USE CAUTION NOT TO DAMAGE THE HEATER CORE AT THE PIPE FITTING BY PULLING THE HEATER HOSES.

WHEN REINSTALLING THE VALVE COVERS, BE SURE TO FOLLOW THE DIRECTIONS PROVIDED WITH THE APPROVED OMS SEALER. SPECIFICALLY THE SEALER MUST BE ALLOWED TO CURE FULLY BEFORE THE ENGINE IS STARTED.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.