Two problems related to manifold/header/muffler/tail pipe have been reported for the 1999 Cadillac Deville. The most recently reported issues are listed below.
The contact owns a 1999 Cadillac Deville with a v8, 4. 6 liter north star aluminum engine. He stated that after driving the vehicle for 5 minutes, the vehicle would overheat. This was a frequent failure occurring in the vehicle. The vehicle was inspected by his independent mechanic and found that the fly-wheel failed and the right cylinder was missing the soft plug behind the water pump. The vehicle was also found to be leaking anti-freeze into the engine cylinders and through the tail pipe. The transmission was dropped in order to replace the fly-wheel and the freeze plug was also replaced by an independent transmission station. The failure persisted. The manufacturer was contacted and they advised him to replace the engine at his own expense. No additional repairs were made to the vehicle. The failure mileage was 148,987 and the current was approximately 149,000. The VIN was not accepted.
Vehicle overheated due to exhaust fumes getting into the cooling system. This caused the head gasket to fail. This incident happened three times. Took vehicle to a mechanic, who changed out the water pump thinking it was the problem at that time. Consumer contacted the dealer, and they were aware of the problem. Also, contacted the manufacturer. However, problem recurred. Head gasket failure, vehicle became a hazard during the first incident due to the fact car was traveling on a 2 lane highway through mountain terrain. The engine was the victim of a botched head repair. Several of the head bolt holes have had custom helicoils installed by local Cadillac dealership. Their mechanic botched the repair and they did not hold. As a result this engine has a coolant leakage problem.