Problem Reports
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1999 Cadillac Seville SLS
Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator
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.
Oil Leak From Lower Engine Area
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.
Stalling Due to Failed Crankshaft Position Sensor
The crankshaft position sensor may fail causing the engine to stall intermittently, the Check Engine Light may or may not illuminate.
Trunk Lid Won't Close Due to Trunk Pull Down Switch Failure
The trunk pull down switch may fail causing the trunk lid not to close completely. Our technicians tell us that the failed switch can be replaced without changing the complete pull down motor assembly.
Coolant Leaks From Water Pump and Radiator
The water pump and/or the plastic side tanks on the radiator may leak causing a loss of coolant. The engine may overheat due to coolant loss. Continued coolant loss after external leaks have been repaired could indicate a blown head gasket.
ABS Light Due to Control Module Failure
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.
The Fuel Pump May Fail Causing the Engine to Stall or Crank Over But Not Start
The fuel pump may fail causing the engine to stall and not restart. Our technicians recommend replacing the fuel filter every 30,000 miles to help prevent undue strain on the fuel pump.
Check Engine Light Due to Intake Manifold Vacuum Leaks
An intake manifold vacuum leak can develop from a variety of sources, often causing illumination of the Check Engine Light with codes P0171 & P0174 stored. Thorough diagnoses will be necessary to pinpoint the cause in order to make the correct repairs. A "smoke" machine is often used to isolate the cause of difficult to find vacuum leaks.
Transmission Fluid Leak From Cooler Line
An automatic transmission fluid leak may develop from the rubber section of a transmission cooler line. In some cases the rubber section of hose can be replaced. In others, the complete cooler line must be replaced to correct this type of leak.
Rough Idle Due to EGR Valve Sticking Open
The EGR valve may stick open, causing a rough idle and/or the Check Engine Light to illuminate.
Engine Overheating Due to Leaking Headgasket
Overheating of the engine may cause the cylinder head to expand, severely straining the head bolts and damaging the threads in the engine block. This commonly results in a blown head gasket. Our technicians tell us the engine block threads must be repaired before the cylinder head is reinstalled.
The Parking Brake May Not Automatically Release
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.
Check Engine Light Due to Gas Cap Issue
A Loose or worn gas cap may cause Check Engine Light to illuminate.
Excessive Engine Oil Consumption
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.
Car Won't Start and Security Light is On
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.
Electronic Level Ride System May Fail
The electronic level ride system may not work properly; this may result in the rear of the vehicle riding too high or too low. Our technicians tell us that a height sensor or exhaust valve failure are common issues with this system. Proper diagnoses will be necessary to confirm the exact fault.
Transmission Leak From Output Shaft Seal
One or both transmission output shaft seals may leak. Our technicians tell us that worn bushings inside the transmission could be the cause of the damaged seals. Our technicians tell us that if a bushing is worn, excess play will be noted where the drive axle attaches to the transmission.
Corrosion on Battery Cable Ends
The battery may leak acid at the battery cable connections. As a result corrosion may form on the battery cable ends. Leaking batteries should be replaced and the cables need to be thoroughly cleaned or replaced if necessary.
High Pressure Power Steering Hose Can Leak Fluid
The high-pressure power steering lines are known to leak.
Air conditioning compressor may leak or become noisy
The air conditioning compressor may become noisy or develop a refrigeration leak, requiring replacement.