1991 Cadillac DeVille Problems

The torque converter clutch (TTC) may stop working due to an internal transmission failure.

The rubber section of an automatic transmission cooler line may develop a fluid leak .

One or both transmission output shaft seals may leak.

The engine may develop oil leaks from the lower crankcase portion of the engine block.

The crankshaft position sensor may fail causing the engine to stall intermittently, the Check Engine Light may or may not illuminate.

Overheating of the engine may cause the cylinder head to expand, severely straining the head bolts and damaging the threads in the engine block.

Illumination of the check engine light may be the result of a loose or worn gas cap.

Failure of the catalytic converter can result in illumination of the Check Engine Light.

Water may be drawn into the secondary air injection (AIR) pump causing the pump to fail and the Check Engine Light to illuminate.