Most common 2005 Cadillac STS problems
Share of the 101 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 →
2005 Cadillac STS recalls (3)
Power train › Axle assembly › Axle shaft › Seal
On certain passenger vehicles, the rear axle pinion seal does not meet all of the specifications and May experience a fluid leak.
Remedy: Dealers will replace the pinion seal free of charge. The recall began on February 1, 2008. Owners May contact Cadillac at 1-800-458-8006 or http://www.Cadillac.com; Pontiac at 1-800-620-7668 or http://www.Pontiac.com;…
Suspension › Rear
Certain vehicles have a left or right rear suspension toe link that could separate because of an incorrect weld.
Remedy: Dealers will inspect the right and left toe link and replace as required. If a toe link is replaced, the dealer will perform a wheel alignment. The recall began on May 3, 2006.
Fuel system, gasoline › Delivery
Certain vehicles equipped with v6 engines May have a condition where fuel is no longer supplied to the engine. This condition occurs without the illumination of the fuel level low indicator light or the warning chime.
Remedy: Dealers will reprogram the electronic control module (ECM) with new software free of charge. Owners were notified in December 2005 and asked to maintain at least 1/4 of a tank fuel level to avoid this condition until…
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2005 Cadillac STS:
Failure of the rear differential
Odi evaluated two different alleged defects involving rear drivetrain components during this preliminary evaluation.GM is conducting a recall to address one of the defect conditions and odi has opened an engineering analysis to continue its investigation of the other alleged defect.
What 2005 Cadillac STS owners say
Electrical system all 23 →
Tl* the contact owns a 2005 Cadillac STS. While driving 35 MPH, the vehicle shook and the check engine light illuminated. The vehicle was driven back to the contact's residence and smoke emitted from the engine. The vehicle was able to restart. The vehicle was towed to an independent mechanic who diagnosed that the ignition coil had total meltdown surrounded by small flames, and the fuse was blown for the odd injectors. A fire report was not filed and there were no injuries. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was 82,920.
My 2005 Cadillac STS brakes locked up and caused my car to crash. After research I am showing that there was a recall regarding the brake system. In addition, when changing gears you can hear the gears changing from the outside of the car. I researched this as well and apparently there is a defect and recall on the axle. I am not happy about this vehicle that I just purchased for alittle over 7 months. There is also an electrical problem. As I am driving, the hood ajar light comes on and there is no sign of my hood being ajar. In addition, the transmission seems as thought it is going out as well. Before I consult with an attorney I wanted to first give GMC an opportunity to resolve this issues. My vehicle has less than 100,000 miles. Also, please note that due to the electrical problem, my reverse lights has never worked. The unknown other would be the axle and transmission.
Engine & cooling
The vehicle intermittently loses engine/ electrical power while driving. When the power loss occurs, brakes and steering lose proper functionality creating a threat to the driver and passengers as well as other motorists. The vehicle then is unresponsive to the proper starting procedure. Restarting the vehicle is inconsistent. It May start immediately upon command or it May cause a theft procedure to initiate. The vehicles dic will possibly show the following prompts just before the shutdown failure occurs; service vehicle soon, service stability system soon, service A/C system soon. During the shutdown failure, no electrical components are operable but power is still available to the car allowing the dic to prompt 'no fob detected' or 'theft attempted' and the fob will intermittently allow you to send lock/ unlock commands during the shutdown failure. …
Tl*- the contact was driving when she lost consciousness for about 30 seconds. The contact believed that loss of consciousness was due to fumes in the passenger compartment. At the time of the incident the vehicle was traveling at 40 MPH under dry conditions. As a result the contact's vehicle crashed into another vehicle. The contact stated that she was unaware that she was in a crash, and that the air bags deployed. She regained consciousness because of the gases caused by the air bag's deployment. The contact had the car taken to the dealer to check if fumes were leaking into the passenger compartment. The contact stated that she has a police report from the crash.
Transmission & drivetrain
The contact owns a 2005 Cadillac STS. The contact stated that while the vehicle was parked in the driveway, the contact became aware of a fluid leak. There was no warning light illuminated. The vehicle was driven to an independent mechanic where it was diagnosed with a pinion seal leak on the rear axle. The local dealer was contacted; however, the vehicle was not repaired because the vehicle was not under recall. The manufacturer was made aware of the failure. The failure mileage was approximately 92,721.
Driving on the highway when there was a sudden loud bang, my car swerved, my rpms revved up, white smoke and I smelled burning. I pulled over and had it taken to the local certified Cadillac dealership, my rear differential needs to be replaced related to a rear pinion seal leak. There's a recall for that exact problem for my year and model but my VIN isn't covered. How can I get my VIN on the recall list?
2005 Cadillac STS engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 3.6L 6-cyl | 5-speed automatic | RWD | 16 / 23 / 18 |
| 4.6L 8-cyl | 5-speed automatic | RWD | 15 / 23 / 18 |
| 4.6L 8-cyl | 5-speed automatic | 4WD/AWD | 14 / 21 / 17 |
EPA ratings. Class: Midsize car.
Frequently asked questions
Is the 2005 Cadillac STS a good car?
Based on 101 owner complaints filed with NHTSA, the 2005 STS rates avoid: 5.9× as many complaints as a typical year of the STS at the same age. It is one of the STS years we suggest avoiding. 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 2005 Cadillac STS?
The electrical system — 23 complaints, 23% of all complaints for this model year, most often about ignition. Next are the engine & cooling (19) and transmission & drivetrain (18).
How many recalls does the 2005 Cadillac STS have?
There are 3 recalls for the 2005 Cadillac STS, the most recent from December 20, 2007 (seal). Recall repairs are free at any authorized dealer — check whether yours has been done with the 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 2005 Cadillac STS problems happen?
The median mileage reported in complaints is about 57,000 miles; 40% 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.