2021 GMC Yukon engine problems

ENGINE

I am filing this complaint regarding repeated catastrophic engine failures in my 2021 GMC Yukon Denali equipped with the 6.2L L87 V8. I purchased this vehicle as a GM Certified Pre-Owned vehicle. At approximately 7,000 miles, the engine developed a knocking noise and was determined to require complete replacement. I brought the vehicle to the dealership on May 19, 2025, and it remained there until September 17, 2025—nearly four months—while the replacement engine was obtained and installed. Since receiving the replacement engine, I have driven approximately 6,000 miles. On August 4, 2026, I was informed by the dealership that the replacement engine has also failed and requires another complete engine replacement. This means my vehicle has now experienced two major engine failures at extremely low mileage, including failure of the replacement engine. I understand that the 6.2L L87 engine has been subject to a GM recall involving potential engine failure and loss of propulsion. I have now learned that NHTSA has escalated its investigation into continued failures involving these engines, including failures occurring after the recall remedy. My experience appears directly relevant to that investigation. I regularly transport my children in this vehicle and am extremely concerned about the possibility of an engine failure occurring while traveling at highway speeds or with my family in the vehicle. I feel fortunate that the previous failures did not occur under those circumstances. I have contacted GM and requested that they repurchase or replace my vehicle. GM denied my request and has refused to provide me with a reason for the denial. I am asking NHTSA to document my complaint and investigate whether the existing recall remedy is adequately addressing the underlying safety defect, particularly given that my replacement engine failed after only approximately 6,000 miles.I can provide repair orders, recall documentation, mileage records, and correspondence with GMC

NHTSA complaint #11758697 — an unverified report by a vehicle owner.

ENGINE

I am writing to report my 2021 GMC Yukon Denali. This vehicle recently suffered a catastrophic failure of its 6.2L V8 engine while traveling on the freeway with my family inside, creating a severe and terrifying safety hazard. This failure occurred after my vehicle was supposedly remedied under GM’s official safety recall for the known L87 engine defect (Recall N252494001). As the National Highway Traffic Safety Administration's (NHTSA) recently escalated Engineering Analysis reflects, the recall inspection and 0W-40 oil remedy are failing to prevent these engines from destroying themselves. My experience is direct evidence of this continued safety defect. GM has since now fully replaced my engine however only reimbursed me 30% of what it cost to tow to their dealership. Thank you for your consideration.

NHTSA complaint #11758771 — an unverified report by a vehicle owner.

ENGINE

As I was driving, the vehicle's air conditioning suddenly began blowing warm/hot air. Moments later, the check engine light and all electronic service stability lights illuminated on the dashboard. Simultaneously, the vehicle suffered a complete loss of electronic brake assist, resulting in an extremely hard brake pedal and a severe reduction in braking power. The vehicle also displayed a "No Drive Mode Available" message. Third-party diagnostic scanning revealed network power codes U3018, U3505, P00FF, and P0700, indicating a total loss of power to the Body Control Module (BCM). This is the second life-threatening incident with this vehicle I have experienced following a previous highway engine stall due to engine recall. The vehicle was towed to a GM dealership for diagnostic and emergency electrical repairs.

NHTSA complaint #11757731 — an unverified report by a vehicle owner.

ENGINE

The vehicle was driving down the highway when the oil pressure instantly dropped. 2021 Yukon’s safety system advised pulling over immediately, engine warning light appeared, and vehicle turned off. No prior indications of an issue. It would not restart and was towed to mechanic. Independent service center diagnosed issue as a broken crank shaft. It now needs the engine replaced and does not fall under the recall vin numbers acknowledged for the same issue.

NHTSA complaint #11756557 — an unverified report by a vehicle owner.

ENGINE

On July 28, 2026, while traveling on vacation with my family, our vehicle experienced a catastrophic engine failure. There were warning lights displayed for 30 seconds prior to the engine failure. On July 23, 2026, one day before taking the vehicle to the dealership, the following warning indicators appeared on the dashboard and then disappeared: “Service ESC,” “Service Traction Control,” and a flashing engine light. We took the vehicle to the dealership on July 24, 2026, because we wanted to be proactive and ensure that the vehicle was safe to operate. The dealership inspected the vehicle but reported that no diagnostic trouble codes were identified and no issue was found. We picked the vehicle up from the dealership on the evening of July 27, 2026. On July 28, 2026, while traveling on the highway approximately 2.5 hours from home, the same warning messages appeared on the dashboard again. Because we were traveling at highway speeds and vehicle speed management was becoming an issue, I immediately exited the highway and stopped in a parking area. I placed the vehicle in park, at which point the engine began idling extremely rough. I could feel the vehicle shaking while sitting in the driver's seat. I exited the vehicle to open the hood, but before I was able to do so, I noticed gray smoke coming from the exhaust. We located a GMC dealership approximately two miles away. Because of the vehicle's condition, we drove there slowly on the frontage road at approximately 15 mph and dropped the vehicle off for diagnostic inspection. The GMC dealership subsequently diagnosed the vehicle with catastrophic engine failure and recommended that the engine be replaced. The vehicle remains at the dealership and is available for inspection.We made a reasonable effort to have the vehicle inspected before our trip because we were concerned about the warning indicators and wanted to ensure that the vehicle was safe to travel.

NHTSA complaint #11756194 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Yukon. The contact stated that while driving approximately 50 MPH, the check engine warning light started blinking and the vehicle started shaking violently. The vehicle was pulled over to the side of the road and turned off. The vehicle was then towed to a dealer where it was diagnosed with a stuck lifter. The contact was informed that the lifters needed to be replaced. The vehicle was not repaired. The contact believed that the failure was associated with an undisclosed recall number. The manufacturer was notified of the failure. The failure mileage was approximately 100,000.

NHTSA complaint #11753973 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Yukon. The contact stated that while driving at an undisclosed speed, there was a misfire coming from the vehicle, the vehicle was shaking and vibrating abnormally before the vehicle went into LIMP Mode. The traction control light and other unknown warning lights were illuminated on the instrument panel. The vehicle was taken to a dealer to be diagnosed. The vehicle was diagnosed with a lifter failure inside the engine. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 86,000.

NHTSA complaint #11753121 — an unverified report by a vehicle owner.

ENGINE

Knocking sound and flashing engine light came on. When brought to dealership it was determined that lower bearing failure took place requiring full engine replacement. '

NHTSA complaint #11752786 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Yukon. The contact stated that while driving at slow speeds from 2 - 30 MPH, the vehicle hesitated and bucked while accelerating and switching between 4- and 8-cylinders operation. The vehicle was taken to the local mechanic who installed a part used to override the engine cylinder mode, and the engine only operated using 8 cylinders. No further information was available. The manufacturer and local dealer were not contacted about the failure. The failure mileage was 102,000.

NHTSA complaint #11751456 — an unverified report by a vehicle owner.

ENGINE

Seems to be not accelerating properly as if the propulsion is not there. Also, when switching gears it seems as if it is slipping or missing to keep up with the propulsion. Lastly, riding with windows down on the highway alongside the concrete median, I can hear like metal clanking or rubbing against one another. Also, I get an oil change at George Ballas GMC on [XXX] and 3 weeks later truck says change oil soon. AND YES THEY RESET THE OIL LIGHT AND I DROVE IT FOR 3 WEEKS AND THE LIGHT POPPED ON!!!! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11750280 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Yukon. The contact stated that while driving at an undisclosed speed, the vehicle made an abnormal sound and failed to accelerate above 25 MPH. No warning light was illuminated. The vehicle was taken to an independent mechanic, who determined that there was metal in the engine and that the engine needed to be replaced. The vehicle was then taken to the dealer, where it remained for eight months before the engine was replaced. The manufacturer was made aware of the failure. The failure mileage was approximately 127,000.

NHTSA complaint #11749937 — an unverified report by a vehicle owner.

ENGINE

I bought the vehicle used with 40,000 miles it’s has 100,856 now the engine shot off while I was driving and brought it to the GMC dealer that GM instructed me to the dealer had me pay 284.95 for inspection and then try to charge me 1284.95 for a complete tar down of the engine because of misfiring and ESC error codes.

NHTSA complaint #11747447 — an unverified report by a vehicle owner.

ENGINE

Engine overheated and performed an emergency shutdown while driving through Atlanta on my way to vacation with my family. We lost propulsion and had to cross 5 lanes of traffic to find a shoulder to pull over to. The engine shut down and we were left stranded 500 miles from home with our 3 children in a boiling car. The vehicle was inspected and passed the recall test 6 weeks prior to this incident. After the first failure we attempted to extend our power train warranty to which we were told it had too many miles by GM. The GM dealership and service center where the vehicle was towed confirmed the engine needed to be replaced and GM confirmed it falls under their extended warranty. However, GM refuses to cover any additional expenses incurred from their engine failure.

NHTSA complaint #11746548 — an unverified report by a vehicle owner.

ENGINE

engine failure causing vehicle to be unsafe to drive. our vehicle was not included in the L-87 loss of propulsion GMC recall even though it is a 2021 Yukon 6.2L. the engine failure is same as those being recalled. vehicle is currently at Cardinale GMC in Seaside CA waiting repair. the only warning of the impending failure was loud noises coming from engine compartment while driving on the freeway. Cardinale confirmed the problem and our extended warranty is covering repair costs. it seems that GMC should have included our VIN in the recall.

NHTSA complaint #11746057 — an unverified report by a vehicle owner.

ENGINE

Took my vehicle in for general maintenance upkeep (oil change, tire rotation, vehicle inspection) and was notified my engine is already showing signs persistent with the recall on the 6.2L L87, specifically not holding oil. The dipstick was not showing signs of any fluid being in the vehicle.

NHTSA complaint #11745006 — an unverified report by a vehicle owner.

ENGINE

On May 27, 2026, I was on my way home from work when I went to accelerate the vehicle and all the sudden it started shaking and the check engine light came on with the EBS. I was able to get the vehicle to a repair shop local the next day, who took the car apart. What was thought to be an easy fix of spark plugs and fuel injector, became even more after they put back together and the cylinder was still misfiring. After several hours of taking apart the engine, the mechanic determined that the hydraulic valve lifters had failed. This has been an ongoing issue with with the 5.8L V8. Due to a recall not being under the vin yet, i have now incured a $16k expense to add an engine to it after i purchased it in Nov of 25 at $97,000. This is a saftey issue and luckily no one was hurt when the car started shaking and couldn't go over a certain speed. I want this reviewed and looked at for possible reimbursement as there have been several other vehicles with the same known issue.

NHTSA complaint #11743482 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Yukon. The contact stated that while pulling into the yard, the vehicle made an abnormal clanking sound and a hammer-like sound. No warning light was illuminated. The contact stated that the failure was related to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling), but the VIN was not included. The vehicle was taken to the local dealer, where it was diagnosed with metal fragments inside the engine. The vehicle was repaired, but the failure recurred while driving a month later. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 76,000.

NHTSA complaint #11742695 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING:COOLING SYSTEM

The contact owns a 2021 GMC Yukon. The contact stated that while pulling into the yard, the vehicle made an abnormal clanking sound and a hammer-like sound. No warning light was illuminated. The contact stated that the failure was related to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling), but the VIN was not included. The vehicle was taken to the local dealer, where it was diagnosed with metal fragments inside the engine. The vehicle was repaired, but the failure recurred while driving a month later. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 76,000.

NHTSA complaint #11742695 — an unverified report by a vehicle owner.

ENGINE

I am filing a complaint regarding my 2021 GMC Yukon due to a serious engine failure involving the camshaft, lifters, and crankshaft. The vehicle began exhibiting engine ticking and knocking noises, rough idle, loss of power, and reduced performance. These symptoms progressively worsened and ultimately resulted in major engine damage. The vehicle was diagnosed with failed lifters and camshaft damage, which required extensive repairs. In addition, the crankshaft failed, resulting in catastrophic engine damage and making the vehicle unsafe to operate. These are critical engine components that should not fail prematurely under normal driving and maintenance conditions. The most serious concern is safety. The engine's loss of power and deteriorating performance created the risk of sudden failure while driving. A vehicle that loses power in traffic, while merging, crossing intersections, or traveling at highway speeds can create a dangerous situation and increase the risk of a crash. Occupants and other motorists could be placed at risk if the engine fails without warning. My vehicle has been properly maintained and serviced. Despite regular maintenance, these major engine components failed unexpectedly. I am aware that other owners of GMC and Chevrolet vehicles equipped with similar engines have reported comparable camshaft and lifter failures, suggesting a potential defect rather than an isolated incident. The failure resulted in significant repair costs, loss of vehicle use, and concerns about the long-term reliability and safety of the vehicle. I believe these engine failures may indicate a manufacturing or design defect affecting 2021 GMC Yukon vehicles. I respectfully request that NHTSA investigate camshaft, lifter, and crankshaft failures in the 2021 GMC Yukon and determine whether a safety-related defect exists that warrants corrective action or a recall.

NHTSA complaint #11742402 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Yukon. The contact stated that while driving approximately driving 45 MPH and turning onto an exit the vehicle suddenly reduce speed and lost power and the message "Press Start" had displayed. The contact stopped the vehicle and eventually restarted the engine and the vehicle operated as normal. The next day the vehicle was driven to the local dealer who was unable to duplicate the problem and determine the cause of the failure. The manufacturer was not yet contact regarding the failure. The failure mileage was 42,000.

NHTSA complaint #11741740 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2021 GMC Yukon. The contact stated that while driving at an undisclosed speed, the vehicle would independently activate Limp mode and would not accelerate past 30 MPH. In addition, the vehicle would not shift into the Reverse gear as intended. The vehicle was taken to a local dealer, where it was diagnosed with error codes: P0777 and P18A1. The vehicle was not repaired due to parts being on backorder. Upon further investigation, the contact related the failure to an Unknown NHTSA Campaign; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 90,000.

NHTSA complaint #11741458 — an unverified report by a vehicle owner.

ENGINE

Post-Recall Low Oil Warning + Performance Issues on 2021 GMC Yukon Denali – Campaign 25V274000 Vehicle: 2021 GMC Yukon Denali, 6.2L V8 Recall: 25V274000 Owner: One owner since new (purchased 2021) I had recall campaign 25V274000 performed on my vehicle. This was the first low oil warning I have ever received since purchasing the SUV new in 2021. I have always followed the vehicle’s oil life monitor with no prior issues. The change oil light appeared at roughly 7,500 miles after the recall service (when I already had a service appointment scheduled). About one week later, the low oil warning came on. I had the vehicle towed to the dealership and did not drive it after the warning. Since the recall service, I have also experienced performance issues including noticeable stuttering that was really evident before I towed it in. The dealership initially agreed to a consumption test but later acted like it was not needed, said everything was fine, and were dismissive — blaming me for not following their sticker. I am concerned the recall remedy is not fully effective. Please investigate this matter. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11741660 — an unverified report by a vehicle owner.

ENGINE

Engine is misfiring. Took it into local mechanic who mentioned he has seen many similar issues and knew there was a recall for similar 2021 Yukon engine issues but for some reason this model was not included. He encouraged me to trade in the vehicle because most likely the engine would need to be replaced (or a $10,000 repair) and it was not save to continue to drive in this condition. I call GMC and they suggested I contact the NHTSA to request that this year and model be added to the recall listing for other similar Yukon engines.

NHTSA complaint #11740700 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

The contact owns a 2021 GMC Yukon. The contact stated that the vehicle had a rough idle. There was an abnormal ticking and rattling sound detected. The vehicle lost oil pressure. The contact located smoke emerging from the vehicle. The engine light was illuminated. The vehicle was taken to the local dealer, where it was diagnosed with a failure with cylinder five, no compression, and bearing failure. The dealer suggested the engine be replaced. The vehicle was not repaired. The contact indicated that the failure was related to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling) but was not included in the recall. The manufacturer was contacted who referred to the NHTSA hotline. The failure mileage was unknown.

NHTSA complaint #11740113 — an unverified report by a vehicle owner.

ENGINE

I was driving in the left lane on [XXX] , a 4 lane interstate just outside of Cleveland when i lost engine propulsion. Engine RPMs dropped to under 1000rpm, and quit responding to throttle. I had to change lanes and coast until there was a shoulder available to stall out at while i awaited a tow. No warning lamps until i tried to restart vehicle. Engine cranked but wouldnt start. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11738939 — an unverified report by a vehicle owner.

ENGINE

My 2021 GMC Yukon AT4 with a 5.3L engine failed as I was driving down a highway going to my child's ballgame. It put me at risk of wrecking on the highway with other traffic around me as I needed to get my vehicle off the road way. Thankfully, I was able to get the vehicle to a safe spot to get it towed. After having the vehicle towed to my local GMC dealer, they determined my lifters in my engine failed and my camshaft had irreparable damage. GM has a lawsuit going on right now against their faulty lifters in their engines. The dealership told me they recalled the 6.2L engine, but not the others. It is shameful that they haven't recalled the other engines that also have the same lifters with the same active fuel management system. My power trained warranty has just expired and they want to charge me over 15,000 to replace the engine and radiator. I am now fighting with GM to help cover this expense that I feel a recall should take care of. These vehicles are not safe on the road with these faulty engine systems specifically the lifters inside them that are known to fail and GM is aware of this and not doing anything. Please help me and other GM owners get these vehicles recalled and make GM replace these engines at no cost to the owner due to their faulty engine components. My daughter and I could have been seriously been injured or died that day in the highway due to the abrupt engine failure on the highway going 70mph. Thank you for your time and God Bless.

NHTSA complaint #11738315 — an unverified report by a vehicle owner.

ENGINE

Vehicle had lifter failure. This could’ve have caused a devastating accident to myself or family which includes my 8 year old daughter. GMC has knowledge of this problem with this motor

NHTSA complaint #11737463 — an unverified report by a vehicle owner.

ENGINE

Motor started knocking My safety and my family safety was put at risk because we were driving down the street. The car is now at Woody dealership in Naperville, IL. Being inspected as we speak. No symptoms prior to failing.

NHTSA complaint #11736092 — an unverified report by a vehicle owner.

ENGINE

Hello, I was driving on the highway with my family and my engine had a sudden loss of power. I only have 52,000 miles on the engine and it has been serviced the entire time. We almost got in a major accident as we had cars and trucks moving around us at a very high speed as we tried to pull over in the breakdown lane. I brought the car to Daddario GMC in Shelton, CT. They did a diagnostic test and said that cylinder 2 was misfiring. Upon closer inspection they saw that there was oil sitting on top of the piston head which indicates engine failure. I have since contacted GM warranty services given my car was just past the warranty date of November 2025, but still under the 60,000 miles of coverage. I did some research and have seen this is a very common with these engines as GM did a recall on 600,000 already. For some reason my VIN # is not listed on the current recall even though my engine is in the same year as the others that were. I would like GM to cover my engine 100% but was told they may only pay a % to fix it. Can you do anything to help me get them to cover the engine at 100%? I also wanted to let you know about this issue as my VIN was not under recall and this may happen to other people/families who have the same engine as mine that isn't recalled. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11734302 — an unverified report by a vehicle owner.

ENGINE

While operating my 2021 GMC Yukon AT4, my vehicle suddenly developed a popping noise, the check engine light began flashing, and the traction control warning illuminated. The vehicle lost power and had reduced acceleration, forcing me to pull off the road because it was unsafe to continue driving. This created a serious safety risk and appears consistent with reported GM lifter or engine defects.

NHTSA complaint #11734192 — an unverified report by a vehicle owner.