Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1998 Cadillac Seville owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl* the contact owns a 1998 Cadillac Seville. While driving 60 MPH, the temperature warning indicator illuminated and the contact stated that the motor began to overheat. As a result, the contact pulled over to allow the engine to cool. The vehicle was taken to a dealer where it was diagnosed that the radiator needed to be flushed, and the water pump and thermostat needed to be replaced. The vehicle was repaired, but the failure recurred. The vehicle was taken to the dealer again where it was diagnosed that the head bolts were not long enough. As a result, it caused the pressure to lead through the head. The manufacturer was notified of the failure and referred the contact to NHTSA. The failure mileage was 102,000.
The consumer had difficulty shifting the gears when a passer by informed him to exit the vehicle because it was on fire. The fire in the engine compartment totaled the vehicle. The consumer noticed fire coming from the gear shift and was told the fire had come from the engine.
We have a 1998 Cadillac sts and are running into problems with it running hot. After replacing the radiator, thermostat and coolant, there is still the same problem. It will only be after the engine is warmed from driving will this occur, it will start to run hot if you give the vehicle gas to try and get into traffic flow. We have consulted quite a few machanics on this problem and they have all given us the same explanation for the presumed problem. Especially one that use to work directly for Cadillac as a mechanic, they state there is a problem with the steel bolts in the aluminum engine and if there is any type of sudden exceleration then the engine will run hot or overheat. This is a known common problem stated by any mechanic that knows about this type vehicle, especially when they are telling us this happens all the time to cadillacs. …
Tl* the contact owns a 1998 Cadillac Seville. The contact stated that whenever the vehicle stopped or driving various speeds, the engine would overheat and a message informing him to add coolant would display on the instrument panel. The engine coolant was routinely added to the vehicle, but the failure continued. The vehicle was taken to an independent repair shop where the contact was advised to replace the motor. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 138,000 and the current mileage was 140,000.
Car was serviced 2 weeks prior for sluggish performance and huge oil consumption. Car in for service again! Now for blown head gasket problem. This Cadillac has too many dealer/manufacturer problems. Dealer should pay for these problems. Not customer. VIN [redacted] check service history. Unbelievable! Updated 07/25/2012
Dt: head gasket is blown. Vehicle milage is only 78, 000. Consumer doesn't understand how a vehicle that doesn't receive a tune-up until 100,000 miles have a head gasket failure at 78,000. Consumer was told that this problem is a common ocurrance and consumer feels that is unacceptable.
The consumer was having difficulty shifting the gears when a passer by informed him to exit the vehicle because it was on fire. The fire in the engine compartment totaled the vehicle.
This vehicle was purchased in December 2001 as a reaquired vehicle from general motors with a 12 month, 12,000 mile new car warranty with the option for us to purchase an extended new car warranty which we did. This vehicle had an intermittent stalling problem when it was reaquired the first time. When we purchased the vehicle it was sold as having been corrected for the problem. On March 27, 2002, began the series of headaches. The car stalled and we took it to kachine Cadillac. To date this vehicle has been in there 7 times for the intermittent stalling. To date 8/6/02, the car is again in the dealer shop and has been since July 26, 2002. At first they refused to keep the car because they did not know what was causing the stalling and did not want to pay for rental cars for us anymore of which we have now had 7 rental vehicle and to date still are driving a rental. …
Sudden erratic readings such as engine hot, ac off, and service engine soon light on. Engine reduced cylinder operation to 4 cylinders, power reduced significantly. Family in car and heavy traffic could have been dangerous situation in both cases. Found blown head gaskets and coolant entering into 2 cylinders. Mileage only 70,343.
Consumer states the vehicle would intermittently stall while driving at low speeds and/or accelerating from a stop position. The dealer has inspected the vehicle on several occasions, however the problem is reoccurring. Feel free to provide any further information.
NHTSA investigations
Cadillac coolant cooled alternator fires
Engine complaints in other Seville years
Frequently asked questions
How common are engine problems on the 1998 Cadillac Seville?
NHTSA has 21 complaints about the engine & cooling of the 1998 Cadillac Seville, 32% of the model year's 65 complaints. The component named most often is engine › gasoline (8 mentions).
Is there a recall for 1998 Cadillac Seville engine problems?
No. NHTSA lists no engine & cooling recall for the 1998 Cadillac Seville, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1998 Cadillac Seville engine problems start?
Half of the complaints with a recorded mileage happened before about 79,000 miles.
Is it dangerous?
Owners linked 0 crashes, 2 fires and 2 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.