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 2012 GMC Acadia owners, lightly cleaned up (personal details are redacted by NHTSA).
Was waiting on dealership to catch up to bring in for a transmission problem. I know it is transmission related due to not wanting to shift properly and the fact my friend has same make and model only about 100000 more miles than mine does was doing same symptoms and she took to 3 or 4 mechanics and all said nothing wrong..no codes show up...needless to say after about 2 months it stalled out on her on interstate with speed limit 75 and she barely moving. I myself was at a sharp curve in turn lane waiting on traffic and when I braked to stop it made horrible sound and felt like brake was pushed through floorboard. When I was clear to go i push accelerator down to the floor and am barely inching along and am now stuck in the road in a 90 curve where its hard to see traffic coming. This was very scary and traumatic having this happen. …
The contact owns a 2012 GMC Acadia. The contacts stated that while driving at an undisclosed speed, the vehicle lost velocity while depressing the accelerator pedal. The message "Engine power reduced and service traction control" was displayed temporarily. The contact managed to pull over the shoulder of the road and had the vehicle towed to a local independent service lot where it was diagnosed with metal debris in the engine which required an engine replacement. The local dealer was contacted. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 128,000.
The contact owns a 2012 GMC Acadia. The contact stated that while driving 70 MPH, the RPM would rise to 4,000 however, the vehicle failed to respond as intended. The check engine warning light was illuminated. The contact pulled over to the side of the road and inspected the vehicle and became aware of smoke coming from the engine compartment. The vehicle was towed to an independent mechanic where it was diagnosed that the engine block, camshaft, reverse gear, and transmission housing needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 158,000.
The contact owns a 2012 GMC Acadia. The contact stated that shortly after purchasing the vehicle, the check engine warning light illuminated. The vehicle was taken to the local mechanic who discovered that the catalytic convertor was faulty and needed to be replaced. The mechanic also inspected the vehicle and determined that the steering rack, front struts, and suspension control arms were also faulty and needed to be replaced. The vehicle was not yet repaired. The local dealer was notified of the failure, but no assistance was offered. The manufacturer was not contacted. The failure mileage was 130,000.
The contact owns a 2012 GMC Acadia. The contact's wife stated that while driving at an undisclosed speed, the vehicle lost motive power with the check engine warning light illuminated. The vehicle was able to be restarted; however, the failure persisted. The vehicle was towed to the dealer, but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 172,000.
The contact owns a 2012 GMC Acadia. The contact stated that the vehicle failed to release from low gear while at a stop. The transmission was backed up. The engine light was illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, who confirmed there were no recalls. The failure mileage was approximately 213,766.
The timing chains went on the engine at 148,000 miles. Which is known for 3.6l engines. Gm needs to own up to their faulty manufacturing on these engines. I need this vehicle for my children. This is the second time I have to put another engine in this truck. Thankfully when I purchased this vehicle it had a warranty but it only cover so much so I had to put a jasper motor in it instead of a brand new one from GM itself and now this jasper motor died after only driving it 22,000 miles and getting my oil changed every 3,000 miles. Single mom of soon to be 3 children i can't afford another 3 row seating Vehicle.
While driving the vehicle it just shut off for no reason which created a safety hazard! We were then forced to have it towed to a nearby repair shop, because we did not want to take the chance to start the vehicle and have the same thing happen again. The repair shop did their diagnosis and informed us it was a broken timing chain but couldn't tell us if any other damage was done to the motor, without completely tearing it down. The decision was made to wait and it remains sitting at the repair shop.
I was driving 40 mph, when warnings appeared on my dash. "Service Stabalizor control", "Traction control turned off", "power is reduced", and the check engine light came on. I lost power as if engine quit, no acceration, but then came back intermittent. If I had been on a highway going 65 mph, in heavy traffic, there may have been an accident. Power steering remained on. I took to an auto service business, and they were unable to find the problem. Code indicated a fuel pressure problem.
142,000 miles and timing chain is bad. A very known issue and a very common issue in the GMC Acadia Denali which I think should be repaired by GM! I only owe $4,000 on the car and it's going to cost me 3,000 to get it fixed that is ridiculous so I think you should stand behind your workmanship and your quality of vehicles that you build GM and fix it take care of your customers as we keep buying this type of junk
Engine complaints in other Acadia years
Frequently asked questions
How common are engine problems on the 2012 GMC Acadia?
NHTSA has 37 complaints about the engine & cooling of the 2012 GMC Acadia, 13% of the model year's 296 complaints. The component named most often is engine › crank/camshaft position sensor (1 mentions).
Is there a recall for 2012 GMC Acadia engine problems?
No. NHTSA lists no engine & cooling recall for the 2012 GMC Acadia, though it has 5 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 2012 GMC Acadia engine problems start?
Half of the complaints with a recorded mileage happened before about 100,000 miles, and 15% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 0 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.