2020 GMC Yukon XL: check engine light

Filed Jul 12, 2026 · Engine · TN

My family drove from [XXX] to [XXX]. Upon arrival check engine light came on, we proceeded to a local shop, by the time we arrive check engine light was flashing and engine was knocking and was clearly malfunctioning. Shop owner recommended we transport the vehicle back home as service shops in the area were experiencing high volume and parts shortages. We had vehicle towed to a local shop in [XXX]. The engine is giving diagnostic codes P0300, P050D, [XXX] with internal knocking and tapping. Vehicle has been kept current on all oil changes and has no external leaks. GMC wants at least $12,000 to replace the engine. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 5, 2026 · Engine · TX

The engine light came on and started making noise. We drove it to a mechanic shop, and they said the code stated camshaft and other component issues, but the engine ended up failing completely and was rebuilt. We initially checked for recalls and our VIN did not show any; however, we recently became aware that our engine (6.2L) might be part of the ongoing current problems associated with a recall. We are hoping that GMC will cover any remaining repairs and/or reimburse us for the thousands it has cost us.

Filed Apr 23, 2026 · Engine · FL

Engine started with a rough idle, I attributed this to mileage. Check engine light did not come on until days before scheduling service. Per diagnostic from Chevrolet service department: Lifter roller damaged and camshaft damaged on lobe. need to replace camshaft and lifters. this has been diagnosed by Chevrolet dealer mechanics at Ferman Chevrolet North Tampa, in Tampa Florida. Check Engine Light came on 4 days before I took it for diagnostic. Chevrolet and GMC have issued a recall on 2021+ but this remains outside that recall. I'm quoted for an $11,343 repair on a vehicle that has gotten regular synthetic oil changes at the dealership since I bought it with approx 80k miles on it. Metal was not noticed in the prior oil changes, latest which was

Filed Jan 6, 2026 · Transmission · KS

I was traveling along i80 and suddenly the vehicle shutdown. I put the transmission in Neutral and coasted to a stop. Once stopped, I check It would not start or even turnover at that point. I still had all electrical services and such. The vehicle. I was stranded on i80. Then had to be towed to the nearest GM Dealer in Evanston Wyoming. Heritage Chevrolet GMC. It was left there for diagnosis where their technician, several days later diagnosed it with a bad engine. There was no warning or check engine light that appeared. I even have a picture from a little while earlier while driving earlier that morning. It took it because I was surprised it was getting 28mpg in v8 mode. but I am glad I had that photo to show no diagnostic lights were on.

Filed Jan 4, 2026 · Engine · KY

Knocking noise from engine-no check engine light initially. Next time it was started knocking was still present and the check engine light was on. Contacted Champion Chevrolet in LaGrange KY. Dealership diagnosed problem (Code P0308 - Cylinder 8 misfire). Compression test on Cylinder 8 failed. Removed valve cover and confirmed loud tick in the rocker shaft and worn camshaft lobes. Was told I would need a new engine and that repairing the existing engine was not cost effective. So, $22,722.14 later, i have a new engine in my 2020 GMC Yukon and have the original engine (core charge) in my shop in case it is needed for evaluation to help determine if the GM recall should be expanded to 2020 model year (and others not covered by the current recall).

Filed Nov 5, 2025 · Engine · GA

The vehicle suddenly stopped working while driving with my family of 5 in the vehicle. There was no warning, messages or other symptoms of the problem prior to this. We had no idea there was anything wrong until it just stopped working. Then the engine light came on. Thankfully we were close to an exit and were able to pull off the road. We had it towed to a GMC dealer they found cylinder 7 intake lifter collapsed causing P0300 to set in ECM. Upon disassembly of bank one found lifter guide failed due to lifter collapse leading to camshaft lobe damage. The engine required replacement of camshaft and all lifters. The total cost of repairs was $10,115.72. When I reported this to GMC they said that our vehicle was not part of the current recall for engine failure because it was a 2020.

Filed Oct 14, 2025 · Engine · WI

We have owned the car for five years. We bought it new in 2020. Now, the engine has completely failed. It has the same problems all the recalled GMC Yukon Denali XL 6.2L V8 engines have; lifters are not functioning, cam shaft is destroyed, rods are bent, oil is pooling and the aluminum engine has melted. The engine light suddenly went off and we didn’t have acceleration. The vehicle started “puttering” and didn’t drive well. No warning at all. This is a known issue with GMC (which I just found out about) and I find it absurd I have to pay $26,000 for a new engine which will most likely have the same problem. Luckily nothing happened, but if that happened on the highway with my wife and three young kids in the car it could have been a nightmare situation.

Filed Sep 23, 2025 · Engine, Fuel system · OH

[XXX] [XXX] Phone: [XXX] Email: [XXX] [Date] the federal safety agency Office of Defects Investigation (ODI) 1200 New Jersey Avenue, SE Washington, D.C. 20590 Subject: Safety Complaint Regarding 2020 GMC Yukon XL Denali – Repeated Engine Failures (VIN: [XXX] ) To Whom It May Concern: I am writing to formally file a safety complaint regarding my 2020 GMC Yukon XL Denali (VIN: [XXX] ) which I purchased in 2021. This vehicle has experienced repeated and dangerous mechanical failures that raise significant safety concerns. •March 2024: The oil pump failed, resulting in immediate engine issues. Repairs were completed under warranty, but the check engine light remained on afterward. •April 2024: The vehicle broke down again. At that time, the cams and lifters were replaced in addition to other service, but the underlying issues were not resolved. •August 2025: The vehicle failed once again. After taking it in, the service department could not determine the cause. When they believed they had identified the issue and took it for a test drive, the vehicle broke down again and had to be towed back to the shop. At that point, I was informed that the vehicle now requires a complete motor replacement and a new fuel pump. Each of these failures has left me stranded and placed me and my family in unsafe situations on the road. Despite contacting the dealership (Joseph Cadillac of Dublin), General Motors, and the warranty company, none have taken responsibility to properly resolve the issues. I believe this represents a potential defect in the engine or related systems that could impact many other consumers. I respectfully request that the federal safety agency investigate this matter to determine whether a broader safety recall or manufacturer action is warranted. Thank you for your attention to this matter and for helping ensure consumer safety. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 30, 2025 · Engine · WI

Vehicle suddenly lost power without warning or engine light coming on. Vehicle was inspected and found that the transmission fluid pump failing caused low transmission pressure and replacement was required. 70k transmission fluid change was done per maintenance recommendations. Vehicle had 112k miles.

Filed Aug 2, 2024 · Engine, Transmission · 102,000 miles · AL

The contact owns a 2020 GMC Yukon XL. The contact stated that while his wife was driving approximately 65 MPH, the transmission started to slip out gear and the vehicle was losing motive power. The contact's wife had not observed any warning lights. The contact’s wife drove the vehicle back to the residence and while attempting to place the vehicle in park(P), the vehicle failed to respond. The contact had the vehicle towed to an independent mechanic who diagnosed the vehicle and determined that the transmission needed to be replaced. The vehicle was repaired; however, the contact stated while driving approximately 65 MPH, the check engine warning light illuminated. The contact was able to drive the vehicle to the residence. The contact stated that while attempting to restart the vehicle, the vehicle was idling roughly with white smoke coming from the exhaust pipe. The contact drove the vehicle to a different independent mechanic who performed an engine pressure test and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 102,000.

Filed Jun 5, 2023 · Electrical, Engine · CA

Pressed the air condition button and engine turned off while driving. Vehicle engine knocking and engine shaking. Will not go over 30 miles an hour Take it to the dealership and all they say is it's the air filter. Engine light turns on Traction control light stays on Warning of decrease engine speed Engine not shifting properly High rpm's Dealer says there's nothing wrong

Filed Apr 25, 2023 · Transmission · 127,549 miles · NJ

The contact owns a 2020 GMC Yukon XL. The contact stated while driving 65 MPH, the temperature gauge started rising quickly. The contact stated that the check engine warning light was illuminated. The contact was able to park on the side of the road. The vehicle was not drivable. The contact towed the vehicle to the local dealer, where it was diagnosed with needing the transmission to be replaced. The vehicle was repaired but continued to experience the failure. The contact took the vehicle back to the local dealer, where it was diagnosed with needing the transmission to be replaced for a second time. The vehicle was repaired but continued to experience the failure. The contact took the vehicle back to the local dealer, where it was diagnosed with needing the transmission cooling line to be replaced. The vehicle was repaired but continued to experience the failure and noticed the transmission was leaking. The contact towed the vehicle back to the local dealer, where it was diagnosed with needing the transmission cooling line to be replaced for a second time. The vehicle was not repaired. The manufacturer had not been informed of the failure. The failure mileage was 127,549.