1991 Cadillac DeVille Problems
RepairPal has identified the most common problems with the 1991 Cadillac DeVille based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
The spark plugs should be replaced every 30,000 miles and the spark plug boots should be checked for hot spots and cracks.
Excessive carbon build up in the engine combustion chambers may be the cause of a smog check failure due to excess NOx emissions. A "top engine" decoarbonization cleaning procedure will commonly correct this concern.
The parking brake may not release automatically due to a failed vacuum switch or actuator. Our technicians tell us that if vacuum is supplied to the actuator when the transmission is in gear, the vacuum switch is functioning and replacing the actuator should correct this concern.
Fuel injectors can short-circuit electrically causing a rougher than normal idle and reduced performance.
An updated PROM (Programmable Read Only Memory) chip may be available for the powertrain control module (PCM). Check with your dealer.
The alternator may fail causing the battery to go dead, or an abnormal noise may develop. The dash warning light may or may not illuminate. A failed alternator will require replacement.