2021 GMC YUKON Complaints

Check engine light on, Abnormal engine noise and very significant loss of power. Info registered in the repair invoice: tech verify customer concern, check for code found code p0300 and looking to the live data found miss fire on cylinder number 6, tech swap the coil and spark plug with wire, miss fire still on the same cylinder, tech inspect the injector no problem found, remove the valve cover for inspection found, that the rocker arms is loose, customer approve tear down, tech remove the head on the right side to inspect the lifter and the camshaft, tech found damage on the camshaft, camshaft replacement and lifter is necessary, customer decline repair, tech assemble the engine back and returned to the customer. Customer decide to replace the engine, tech replace the engine test to verify repair vehicle working as design

The contact owns a 2021 GMC Yukon. The contact stated while driving 68 MPH, the vehicle stalled. There was no warning light illuminated. The contact was able to pull over to the shoulder of the road. The vehicle failed to restart and was pushed into a parking lot, where a mobile mechanic determined that the battery and the starter needed to be replaced. The parts were replaced; however, the failure persisted. The mechanic determined that the engine had seized. The vehicle was towed to Pruneda Auto Mechanic, where it was diagnosed that the engine had seized and needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included in the recall. The dealer and the manufacturer were not notified of the failure. The failure mileage was unknown.

On 05.29.25 my 2021 GMC Yukon Denali with 24,000 experienced engine issues and ultimately a total failure. While driving at 65 miles an hour the engine light began blinking and a thumping/knocking noise began on the front passenger side of the vehicle. I was 1 mile away from the GM dealership and went there immediately. They called me two hours later confirming the engine failure and that it would have to be replaced. They stated, however, the engine is experiencing a national backorder. No timeline has been provided for the engine to be received or replaced. I am curious to know if the new engine will come from the same engine group that is currently having issues, and if this can happen again.

The oil level reads way below from what the engine percentage tell me. The vehicle Oil consumption happens to fast. My last two oil changes have been within a month

I am writing to formally file a complaint regarding a serious issue with my 2021 GMC Yukon XL, equipped with the 6.2L V8 gasoline engine and covered under Recall N252494000. The vehicle is experiencing significant power loss while driving, and the engine is making a loud clattering noise, which raises serious concerns about the vehicle’s safety, performance, and long-term durability. These symptoms are ongoing and have severely affected the drivability of the vehicle. Despite these clear issues, the vehicle recently passed a dealership inspection. In an effort to improve performance, a higher viscosity oil change was performed and a new oil cap installed. Unfortunately, these measures have not resolved the problem. The vehicle continues to run poorly and does not perform as expected from a vehicle of this age and mileage. I respectfully request the following: A thorough re-evaluation of the vehicle in relation to Recall N252494000. Immediate corrective action, including repair or replacement of any defective engine components. A detailed explanation of how the vehicle could have passed inspection with such evident performance and mechanical issues. Reimbursement for any out-of-pocket expenses incurred due to this ongoing problem.

I am writing to formally file a complaint regarding a serious issue with my 2021 GMC Yukon XL, which is equipped with the 6.2L V8 gasoline engine and falls under Recall N252494000. The vehicle is losing power during operation and the engine is producing a loud clattering noise, raising major concerns about its safety, drivability, and long-term reliability. Despite these issues being clearly present, the vehicle recently passed an inspection, which raises questions about the adequacy of the diagnostic and repair procedures related to this recall. This situation is both frustrating and alarming. I am concerned that either the inspection was insufficient or the recall-related defect has not been properly identified or addressed. I respectfully request the following: A thorough re-inspection and diagnosis of the engine under the scope of Recall N252494000. Immediate repairs or replacement of defective parts at no cost. A clear explanation of why the vehicle passed inspection despite these evident issues. Reimbursement for any costs incurred if the recall defect caused further engine damage.

While my [XXX] son was driving my 2021 GMC Yukon Denali XL, the engine failed suddenly without warning. The vehicle lost power completely and became inoperable, leaving them stranded far from home. This posed a significant safety risk to my family, especially given the location and time of day. There were no warning lights or messages prior to the failure. The vehicle was towed to a GMC-certified dealership, where the issue was diagnosed as a complete engine failure. The dealer confirmed that internal engine components were damaged and the entire engine required replacement. The dealership performed the repair and confirmed that the issue was consistent with known defects now acknowledged by GM in their 2025 recall affecting vehicles with the 6.2L V8 engine. The problem has been reproduced and confirmed by the dealership. The defective engine is no longer available for inspection, as it was removed and replaced during service. The repair was performed at my personal expense prior to the recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The #3 lifter on my cars engine failed with 80101 miles on it. The engine started to run weak by shuttering. My wife was driving and the car was shaking at a stop and vibrated upon acceleration. I took the car to the dealer and they said the #3 lifter collapsed and could have caused engine failure. The dealer replaced the lifters on that side of the engine.

The contact owns a 2021 GMC Yukon XL. The contact stated while driving approximately 45–50 MPH, the engine was making an abnormal sound. The contact stopped and lightly depressed the accelerator pedal and continued driving. The contact stated that the transmission failed to shift gear. The RPM increased to high. The check engine warning light was illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the transmission needed to be replaced. The vehicle was repaired under warranty, but the failure recurred. The vehicle was taken back to the same dealer who determined that the failure was related to the transmission. The vehicle was repaired but the failure persisted. The vehicle was taken to another local dealer, Hennessy GMC (145 Industrial Blvd, McDonough, GA 30253); where it was diagnosed and the contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 66,000.

The contact owns a 2021 GMC Yukon XL. The contact stated that while driving at various speeds, there was grey smoke coming from the exhaust pipes. The check engine warning light was illuminated. The vehicle was taken to a local dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was not repaired. The vehicle was taken to a local independent mechanic for a second opinion, and it was diagnosed and determined that the engine and brake pads needed to be replaced. The vehicle was not repaired. Upon further investigation, the contact related the failure to an unstated recall; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 125,000.