It has come to our attention that some dealers are replacing worn or damaged camshaft bearings on HT4100 and 4.5L V-8 gasoline engines using non-OEM service parts which, based on information that Cadillac has, may be unacceptable in terms of quality and reliability and/or that the equipment necessary to properly service camshaft bearings in these engines may be unavailable to most Cadillac dealership Service Departments. Proper installation requires precision line boring after installing the bearing inserts, which is the procedure used by our engine remanufacturer. For various reasons, camshaft bearing servicing and replacement on these engines is not recommended and should not be attempted unless the proper equipment is used. Cadillac recommends engine replacement when it has been determined that the camshaft bearings in HT4100 or 4.5L V-8 engines are excessively worn or damaged.
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.