Most common 1999 Cadillac STS problems
Share of the 13 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Cadillac STS complaints by model year
Best STS years: 2002, 1999, 2003. Years to avoid: 2006, 2005, 2008, 2007. Compare all years →
What 1999 Cadillac STS owners say
Engine & cooling
Tl* the contact owns a 1999 Cadillac STS. The contact stated that while driving an unknown speed, the engine rpms increased as smoke was released from under the hood. The vehicle was towed to the mechanic who performed a diagnostic. The failure was located at the engine motor bolts, which had become disconnected due to defective metal. The bolt coil and thread was replaced however, the failure recurred. The manufacturer was made aware of the failure. The vehicle was not further repaired. The failure mileage was 80,000 and current mileage was 100,000. Updated 12/12/12 updated 12/13/2012
1999 Cadillac sevillests. 100,600 miles on odometer. While driving at slow speed (in town) , engine will stop entirely,.- I lose my power steering, brakes and everything else . When I get stopped, engine will start immediately. I'e had the battery checked, and am told all the connections were "fine". A GM dealer recently tuned the engine , and suggested that he replace the wiring" he did so. He did this @ two months before the trouble started. The dealer is out of business. I am afraid to drive the car -- suppose this had occurred while driving 65-70 MPH on the interstate. ??? Please advise me!!! Riving, engine will stop entirely - I lose my power steering, brakes, and everything else. When I get stopped, the engine will start immediately. Have checked battery connection and it checks "fine".
Electrical system
On 11/27/00 car leased from Chevy dealer and OnStar put on by Cadillac dealer. On 01/08/01 car dead in drive,Cadillac dealer installed new battery. On 10/01/01 car quit while driving, Cadillac dealer installed new generator. On 7/18/02 car dead in drive,Chevy dealer replaced generator. On 9/13/04 car dead in drive ,Chevy dealer found nothing. On 11/18/04 car dead in doctor's lot,Chevy dealer found nothing and sent it to Cadillac dealer who also found nothing. Two days later car dead in store lot. Sent back to Cadillac dealer who installed generator and battery. On 8/31/05 car stalled after being picked up from Chevy dealer, returned to Chevy dealer who found nothing. Sent to Cadillac dealer who replaced some computers. Chevy dealer picked car up and drive 9 miles before car quit. Returned to Cadillac dealer who replaced ignition switch. Returned to me. …
Dt*: the contact stated while driving at various speeds the vehicle stalls without warning resulting in loss of power. Afterwards, the vehicle restarts in less than a minute. The stalling occurs intermittently and has gradually become worse. The vehicle was taken to an independent repair shop for inspection who was unable to determine the cause of the problem.
Frequently asked questions
Is the 1999 Cadillac STS a good car?
Based on 13 owner complaints filed with NHTSA, the 1999 STS rates average: 27% fewer complaints than a typical year of the STS at the same age. It is one of the best STS years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 1999 Cadillac STS?
The engine & cooling — 8 complaints, 62% of all complaints for this model year, most often about engine. Next are the electrical system (6) and steering (1).
How many recalls does the 1999 Cadillac STS have?
NHTSA lists no recalls for the 1999 Cadillac STS. You can still confirm with your VIN using our VIN recall check.
What are the best and worst years of the Cadillac STS?
The best years by complaints, compared at the same age, are 2002, 1999 and 2003. Years to avoid or approach with caution: 2006, 2005, 2008 and 2007. See the full Cadillac STS years comparison.
At what mileage do 1999 Cadillac STS problems happen?
The median mileage reported in complaints is about 99,000 miles; 11% of problems with a recorded mileage started before 50,000 miles.
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.