2021 GMC Acadia engine problems

Filed Oct 25, 2026 · Engine, Steering · OH

Car was running great and mins later I get an error stating steering assist is reduced -Drive with care. Vehicles temperature gauge is stuck at cold and fans turn on after turning off the vehicle. I had the vehicle serviced at Dave White on Alexis Rd in Sylvania almost exactly a year ago for the same reason. Was told by the service manager the issue was a computer update and not the thermostat and proceeded to charge for the "update" no issues with vehicle until now.

Filed May 30, 2026 · Electrical, Engine · ME

Display suddenly says "Steering assistance reduced, drive with care" Temp gauge goes to C and stays there. Radiator fans speed up and stay on after the car has been turned off. Dealer unable to find a diagnostic code for the problem.

Filed May 9, 2026 · Engine · MI

I am submitting this complaint regarding ongoing mechanical and electrical issues with my 2021 GMC ACADIA that have been occurring intermittently for approximately the past year and a half. The primary issues involve the coolant temperature sensor, thermostat system, engine cooling fan, and dashboard warning messages. The vehicle repeatedly experiences problems related to the coolant temperature sensor and thermostat. During these episodes, the engine cooling fan continues running even after the vehicle has been turned off, sometimes for an extended period of time. In addition, the dashboard frequently displays the warning message: “Steering Assist is Reduced – Drive With Care.” These warning messages and symptoms occur off and on without consistent resolution. The vehicle has already undergone repairs, including replacement of the radiator, yet the problems continue to return. Despite previous service attempts, the underlying issue has not been permanently corrected. The recurring nature of these problems raises concerns about the reliability, safety, and dependability of the vehicle, especially considering the steering assist warning and possible overheating or electrical system concerns connected to the cooling system malfunction. The repeated failures have caused significant inconvenience, concern for safe operation of the vehicle, loss of confidence in the vehicle’s reliability, and ongoing disruption due to repeated repair needs. I am requesting a thorough diagnosis and permanent repair of the coolant temperature sensor, thermostat, cooling fan system, and any related electrical or control module issues contributing to these recurring problems.

Filed May 6, 2026 · Engine · OK

Bought the acadia in june of 2021, in december of 2022 had to have the radiator replaced due to it leaking. This was found on routine maintenance and was not having any issues whatsoever. I received no alerts on my dash such as a check engine light. Fast Forward to March 2026, I received a message of "steering assist reduced. drive with care." The engine seemed like it was still running despite the car being off. This was happening intermittently and definitely not every time I drove. I made an appointment for the regular oil change and to have this message investigated. Initially they told me it was the temperature regulator, however, they put a new regulator on and tried to re-pressurize the system. The system failed to re-pressurize due to the radiator leaking AGAIN. Of course, there was a 2 year warranty on the radiator after it was replaced initially and now we are about a 1.5 years outside the warranty.

Filed Mar 20, 2026 · Engine · 69,000 miles · NJ

The contact owns a 2021 GMC Acadia. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. In addition, the coolant fan was running after the engine was turned off. The vehicle was taken to Auto Zone to be diagnosed due to the check engine warning light being illuminated. The contact was informed that DTC: P1098; was retrieved, which indicated a fault with the coolant control valve. The vehicle was taken to the dealer, where it was confirmed that the coolant control valve had failed. The vehicle remained at the dealer unrepaired. The contact related the failure to the Manufacturer Recall Number: N252508341. However, the VIN was not included in the recall. The manufacturer was made aware of the failure and advised that the VIN was not under recall. The failure mileage was approximately 69,000.

Filed Mar 4, 2026 · Electrical, Engine · OH

Car has had multiple issues with check engine light coming on for the last 2 years and stays on especially during the winter months. The purge pump has failed multiple times. The cooling fan has run after engine shutting off for multiple years now. The thermostat has been failing for the last 6 months. Now yesterday low power protection suddenly turned on driving on the expressway limiting power in the middle of traffic. Was able to get off at exit without accident and get car home. I guess we have to pay out of pocket to get fixed. This is a known issue that GM fails to include every VIN with the 2021 year or certain models and VINS.

Filed Feb 18, 2026 · Engine · MI

Car was taken in for an oil change at 62k Miles. Dealer advised that it needed a radiator replaced. At 64k miles it was brought into the dealer for warranty work due to a failing thermostat. While being diagnosed, we were told not only the radiator needed to be replaced, but the oil cooler also needed to be replaced. So a 5 year old car with just over 60k Miles had the thermostat/sensor fail and need to be replaced. A radiator fail and need to be replaced and and an oil cooler fail and need to be replaced. Vehicle has been at a GM dealer for all maintenance. No crashes or reasons these parts should fail. Vehicle has never towed anything to but any sort of strain on the cooling system.

Filed Feb 9, 2026 · Engine · 37,000 miles · MO

The contact owns a 2021 GMC Acadia. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated and DTC: P04FB; was displayed. The vehicle was taken to the dealer where it was diagnosed with moisture of the crank case. The vehicle was repaired. The contact stated that the failure was a quick fix and was covered under the warranty. The contact stated that the failure had occurred several times and was covered under warranty. The contact was informed that there was no fix for the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 37,000.

Filed Jan 21, 2026 · Engine · FL

Been happening for a year and a half. Muffler is very loud and rattles constantly. Getting worse over time. There is a current recall but my vin isn’t included even though my car is having the same issue.

Filed Nov 25, 2025 · Engine · MI

Vehicle's engine incurred coolant temperature issues, set dtc code, and cooling fan ran after engine was turned off. Dealer diagnosed as thermostat failure and completed repairs. Dealer checked and found no service assistance for repair even though there was a back order for replacement parts and was secured through dealer in detroit current the federal safety agency id number 110243390 / mfg communication # n252508350 referring to 3.6 v-6 engine. Gmc declined any monetary assistance towards repairs with 76278 miles I also own a 2020 chevrolet blazer with a 3.6 v-6 engine that experienced same failure paid $400 deductable toward repair