This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
full bulletin at NHTSA ↗2008 Cadillac STS engine problems
moderate Owners of the 2008 Cadillac STS have filed 8 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
| Model year | engine complaints |
|---|---|
| 2005 STS | 12 |
| 2006 STS | 18 |
| 2008 STS (this page) | 8 |
When does it fail?
Of the 8 engine complaints filed for the 2008 Cadillac STS, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
No new NHTSA engine complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
full bulletin at NHTSA ↗This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
full bulletin at NHTSA ↗This service bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
full bulletin at NHTSA ↗This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 3 most recent
The Cadillac Company sent me a letter several years ago informing me of a premature timing chain wear and the illumination of the Service Engine light. They knew about this defective engine problem but they did not recall the vehicle. Instead they extended the engine warranty to 10 years or 120,000 miles. I have only 90,000 miles on my vehicle but I've owned it for over 10 years and now the…
Tl* the contact owns a 2008 Cadillac sts. While driving approximately 45 MPH, the engine stalled without warning. The vehicle restarted, but the failure recurred numerous times. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The VIN was not included in NHTSA campaign number: 14v542000 (fuel system, gasoline). The failure mileage was approximately…
Tl* the contact owns a 2008 Cadillac sts. While driving approximately between 55-60 MPH on normal road conditions; the "engine" warning light illuminated on the instrument panel. The vehicle was taken to an authorized dealer for diagnostic testing. The technician was unable to duplicate the failure. Recently, the vehicle was taken to an authorize dealer for inspection for an identical failure.…
Common questions
How serious is the engine problem on the 2008 Cadillac STS?
It's a documented issue but not catastrophic. 8 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 8 complaints filed, engine issues most often appear around 89,312 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.