SOME CADILLACS EQUIPPED WITH AN HT4100 ENGINE MAY EXPERIENCE AN OIL LEAK AT THE INTAKE MANIFOLD TO BLOCK SEAL. THIS CONDITION MAY BE CAUSED BY A SPLIT INTAKE MANIFOLD END SEAL. TO CORRECT THIS CONDITION, NEW SILICONE END SEALS HAVE BEEN RELEASED FOR PRODUCTION STARTING WITH THE 1984 MODEL (REFER TO FIGURE 1). THE BREAKPOINTS ARE AS FOLLOWS: MODEL VIN "D" 139931 "E" 659759 "K" 831723 "C" 213362 TO CORRECT THIS CONDITION ON HT4100 ENGINES PRODUCED PRIOR TO THE LISTED 1984 VIN'S, THE NEW END SEALS HAVE ALSO BEEN RELEASED FOR SERVICE, AND WILL BE PART OF THE INTAKE MANIFOLD GASKET KIT P/N 3634619). THIS NEW SEAL CAN BE IDENTIFIED BY ITS GRAY COLOR. THE PREVIOUS INTAKE MANIFOLD GASKET KIT (P/N 3634584) IS STILL AVAILABLE AND MAY BE USED ON REPAIRS OTHER THAN END SEAL REPLACEMENTS.
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.