1999 Cadillac Seville SLS Problems
RepairPal has identified the most common problems with the 1999 Cadillac Seville SLS based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
One or more heater & AC (HVAC) temperature and/or air delivery mode door actuator may fail, resulting in improper temperature or air delivery. If this occurs, fault code(s) should be stored in the HVAC control module which should assist in diagnoses.
The engine may develop an oil leak from the lower crankcase portion of the engine block. Our technicians tell us that the engine must be removed from the vehicle to properly repair this oil leak.
Problems with anti-theft systems using the raised-chip key can prevent the car from starting. The wires in the steering column to the ignition lock cylinder tend to break. The key and ignition lock cylinder should be replaced to correct this condition.
The air conditioning compressor may become noisy or develop a refrigeration leak, requiring replacement.
It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.
A Loose or worn gas cap may cause Check Engine Light to illuminate.
The spark plugs should be replaced every 100,000 miles. Our technicians recommend replacing the spark plug wires also at this time.
Vehicles equipped with the 4.6L engine may develop excessive oil consumption. Please be advised that under optimum driving conditions, using one quart of oil every 2000 miles is acceptable. This Cadillac standard applies to vehicles with less that 50,000 miles. Our technicians tell us that if you experience excessive oil consumption it may be caused by built up on the piston rings which restricts movement, preventing them from wiping all the oil from the cylinder walls. Oil left behind is then burned during the combustion process. There is a special ring cleaning procedure which can help this situation. The GM service bulletin number is #02-06-01-009C.
The anti-lock brake system (ABS) control module may fail causing the ABS light to illuminate. Failed modules should be replaced to restore ABS operation.