2020 Buick Enclave engine problems

Filed Oct 21, 2026 · Engine · MO

My vehicle is taking oil into the engine and is available for inspection. The mechanic says some component in the engine is taking in oil. I am losing about 3/4 of a quart every 500 miles. He said his best estimate is in months to a year it will blow the motor. I have not taken it to a dealership just the mechanic company I use. No I got a message saying that I needed to add oil about 2 weeks after an oil change. My mechanic checked the oil levels for a couple weeks after that. And thats what I was informed after checking oil levels.

Filed Sep 23, 2026 · Engine, Fuel system · VA

My car started making a loud and rattling noise and when I had my vehicle looked at there was a huge crack in my exhaust pipe which could potentially be leaking harmful toxins in the cabin of my vehicle. I have been to so many places who say they don’t have what they need to repair this and that I need to reach out to GM. I have seen over 30 similar stories in these complaints. This is very unsafe and something needs to be done about this for the 2020 model as it has been done for others. We are afraid to even keep all the windows rolled up with our children inside for fear of carbon monoxide leaking through.

Filed Jul 13, 2026 · Engine · NY

Front exhaust pipe separated from its mounting bracket causing a consistent rattle. This condition is exactly as described in "N222385510 - Special Coverage Front Exhaust Pipe", released in May 2023. Exhaust components in this vehicle are materially the same as the covered 2021 vehicles and thus this vehicle should be similarly covered. Issue has been confirmed by a dealer and is available for further inspection.

Filed May 20, 2026 · Engine · OK

I am submitting a complaint regarding premature exhaust system failure on my 2020 Buick Enclave involving the front exhaust pipe/exhaust manifold/catalytic converter assembly. The issue appears very similar to the conditions described in GM Special Coverage programs N212356540 and N242445280 involving exhaust pipe and bracket failures on related GM crossover platforms. The mounting brackets/support brackets on the front exhaust pipe appear to fail or separate, which places excessive stress on the flex section of the exhaust system. This movement and stress can cause the flex pipe/manifold area to crack and may ultimately damage the catalytic converter assembly itself. My vehicle developed: Exhaust leak Loud ticking/exhaust noise Rich/lean oxygen sensor fault conditions Exhaust fumes entering or potentially entering the cabin Passenger dizziness while riding in the vehicle Concern for carbon monoxide exposure The repair facility documented that the exhaust leak should be repaired as soon as possible because exhaust fumes may enter the vehicle cabin. The estimated repair cost is approximately $1,700 for replacement of the integrated catalytic converter/exhaust manifold assembly. This appears to be more than ordinary wear and tear. The failure pattern is consistent with bracket/support failure causing abnormal stress and cracking in the exhaust system upstream near emissions components. Because these failures can allow exhaust gases and possible carbon monoxide exposure into the passenger compartment, I believe this issue represents a significant safety concern and warrants investigation for 2020 Buick Enclave vehicles and related GM crossover platforms.

Filed May 11, 2026 · Engine · OH

Leaking flex pipe on the exhaust causing undue rattling and possible exhaust fumes entering the passenger cabin.

Filed Apr 20, 2026 · Engine, Transmission · UT

Why enclave Burns about 1 to 2 quarts of oil in between oil changes so I'm constantly having to check the oil level and put more oil in it which come really close to being out of oil and causing the engine to seize Buick says this is normal and I don't think it is I have never had a car that uses oil like this new or used in addition to that the transmission is locked up twice since we have owned it and can't get it out of park can't drive it can't use it. Had to have it towed . The first time that the transmission gave issues it didn't lock up in park it locked up in drive and we couldn't put it in park I was able to get it to the dealer to get worked on it was still under warranty at that time the second time it wouldn't go out of park and could not move it it was stuck wherever we happen to be at and it would not move when they loaded it on the tow truck to tow it down to the dealer the wheels were locked up cuz it was in park and we couldn't it had to just be drug onto the truck.

Filed Apr 9, 2026 · Engine · 52,580 miles · NY

The contact owns a 2020 Buick Enclave. The contact stated while driving at an undisclosed speed, there was an abnormal ticking sound coming from under the hood. Additionally, there was an abnormal exhaust odor inside the cabin of the vehicle. The vehicle was taken to the dealer, who determined that the passenger’s side flex pipe bracket had cracked, causing damages to the catalytic converter. The contact was informed that the flex pipe and catalytic converter needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure but informed the contact that there was no recall associated with the VIN. The failure mileage was 52,580.

Filed Apr 1, 2026 · Engine · LA

I am submitting this formal complaint regarding serious mechanical and safety issues with my 2020 Buick Enclave. These issues have created ongoing financial hardship, significant safety concerns, and an urgent need for investigation and resolution. Over the past several months, my vehicle has repeatedly displayed low‑oil notifications, sometimes occurring within one month of receiving a full oil change. During a recent visit to my mechanic for yet another low‑oil alert, he recalled that I had previously brought the vehicle in for the same issue. After conducting a more thorough inspection, he informed me that there was a failure within the engine/transmission assembly. He showed me the area where oil was seeping from the engine. I also inspected the oil filter and oil plug, both of which showed no signs of leakage. Following this diagnosis, I brought the vehicle to Royal Buick GMC. Their service department performed a SAVI Dongle test and a GM‑Certified Multi‑Point Inspection. The service technician informed me that the vehicle requires a complete engine replacement including the following: replacement of the engine, repair of a rear main seal failure, resealing of the oil pan, and replacement of the lower control arm. It is my belief that these issues are consistent with reported problems. In addition to the oil‑related failures, I have experienced sudden acceleration and jerking while driving. These incidents are alarming and pose a serious risk to my safety and the safety of others on the road. I am deeply concerned that this defect could lead to an accident through no fault of my own. This vehicle is my only means of transportation for work and for caring for my family. The cost and severity of the required repairs are catastrophic, and I believe the manufacturer should be held responsible for addressing these defects. I respectfully request that the federal safety agency investigate these issues and assist in ensuring that GM/Buick replaces the engine for its safe operation.

Filed Mar 27, 2026 · Brakes, Engine · NC

The contact owns a 2020 Buick Enclave. The vehicle was reversed out of the driveway; however, after shifting into drive(D) and depressing the accelerator pedal, the vehicle jerked, vibrated, and the check engine warning light and other unknown warning lights illuminated. After several minutes, the vehicle functioned as intended. A short distance later, the failure reoccurred. The vehicle was taken to Auto Zone, but no cause for the failure was found. The vehicle was taken to a private dealer where it was diagnosed and determined that the catalytic converter was clogged, and that the electronic brake control center module and the transmission module had failed. The vehicle was not repaired. The contact stated that the failure persisted. The manufacturer was not made aware of the failure. The failure mileage was unknown.

Filed Mar 16, 2026 · Engine, Fuel system · CA

The vehicle developed an exhaust leak caused by both weld points on the front exhaust pipe breaking. A dealership inspected the vehicle and confirmed that the exhaust welds had failed, creating a hole in the exhaust pipe and triggering a P0420 catalyst efficiency code. The failure occurred at approximately 31,500 miles. The exhaust leak caused increased exhaust noise and emissions warning codes. The dealership recommended replacement of the front exhaust pipe assembly. This appears similar to known failures on the Buick Enclave and Chevrolet Traverse platform where the front exhaust pipe mounting bracket separates from the pipe due to weld failure. GM has issued special coverage adjustments for similar exhaust pipe bracket weld failures on other model years of these vehicles. The failure occurred at relatively low mileage and appears to be a structural weld defect in the exhaust system.