1999 Cadillac STS Engine cooling Problems
- Complaints
- 6about this part
- Share
- 46%of 13 total for the year
- Median mileage
- 94,794miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 6 complaints about the engine cooling of the 1999 Cadillac STS, 46% of the 13 complaints for this model year. Where a mileage was given, the median is 94,794 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“Our STS stalled several times, but the scariest was on the highway going 65 MPH. The car totally shut off, leaving the car without any power. We were able to guide the car to the side of the highway and thank goodness it started again. On several other occasions, the car would shut off and sometimes wouldn't even start up right away. This was very frustrating and the unknowing, made driving this car very unpredictable. Every time we brought the car to be checked they could not find anything . Finally, an independent mechanic suggested putting in a new starter and this solved the problem. …”
NHTSA complaint #10632731, filed 2014-09, 98,587 miles“1999 Cadillac STS experiencing problems with water sounds behind the dashboard as well as the engine overheating. The dealer replaced the water pump but that did not resolve the problem. While driving the engine light illuminated and a warning bell sounded. The vehicle was taken to the dealer who indicated that the engine had to be replaced. Two months after the engine was replaced the engine idle and overheating light illuminated. The engine was replaced again. The manufacturer was contacted and refused to provide any assistance.”
NHTSA complaint #10122639, filed 2005-05, 67,000 miles“I bought a 1999 Cadillac STS from a dealer in morgantown, wv. It was a couple of years old. Now, it has about 124,000 miles on it. After a few trips to the dealers service department recently, I was told the reason my car was running roughly was because there was a leaking head gasket. Unfortunately, the dealer said, they won't try to repair it because their experience with the Cadillac northstar engine is that if they try to remove it, it strips some sort of bolt or thread, ruining the engine. …”
NHTSA complaint #10176725, filed 2006-12“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.”
NHTSA complaint #10157190, filed 2006-05, 91,000 miles“Vehicle shuts down at cruising speeds, low speeds, and idling. All systems shut down without warning. Vehicle may or may not start back up immediately. I have seen several other complaints on same issue both on NHTSA and other chat boards. This causes a hazardous driving condition for myself and other drivers. Can be especially dangerous on hilly and curved roads because all powered steering and braking shuts down as well.”
NHTSA complaint #10153775, filed 2006-03Related service bulletins
- 10246631Sep 1, 2013Expanded Availability for Remanufacture and Return (R&R) Electronic Control Modules
Engine cooling: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2008 | 2 | 4% |
| 2007 | 1 | 2% |
| 2006 | 8 | 6% |
| 2005 | 7 | 7% |
| 2004 | 1 | 14% |
| 2003 | 3 | 38% |
| 2002 | 1 | 14% |
| 2001 | 1 | 8% |
| 2000 | 2 | 17% |
| 1999 | 6 | 46% |
Other parts of the 1999 Cadillac STS
← All problems reported for the 1999 Cadillac STS
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 28, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology