2020 GMC SIERRA 1500 Complaints

Vehicle has 28,000 miles and auto shop states that the engine is blow, it's knocking and vibrating throughout the engine.

Odometer Fraud. The contact attempted to purchase a 2020 GMC Sierra 1500. The contact discovered a mileage discrepancy. The vehicle was a private sale. At the time of purchase, the mileage was 75,000. At the time of registration, the Carfax Report indicated that the mileage was 175,000.

I was driving the truck on the freeway and the engine completely shut off with no warning. I pulled to the side of the shoulder and I could smell a burning smell. The truck wouldn’t start back up or move in neutral. Towed it to a shop and they said it had a camshaft issue and a slight knocking noise when they got it to fire up only would run for a little then shut back off. Now I’m having to replace the whole engine due to being bad with the cam code and knocking.

The backup camera is too bright at night and therefore useless . Tried searching the web but found no fix that would actually work. Took my truck to the dealer and they never heard of this issue even though there are numerous articles about it on the world wide Web.

February 28th 2026, I was driving on the highway with my children and suddenly without any prior warning my cars check engine light came on. It immediately starting losing power, made a knocking noise, and sounded like it was misfiring. Fortunately I was able to make it safely off the highway and have my car towed to the dealership. This was most definitely a life threatening situation which no one should have to face. The dealership dismantled my engine and i was advised the engine had an internal failure due to the valve lifter , rods , and camshaft damage. When looking online there are many complaints and lawsuits regarding this investigation of GMC’s 5.3 engine. I believe this was due to catastrophic damage of the components and there needs to be a recall regarding this issue. The car has always been properly serviced and regular oil changes.

While driving, my vehicle experienced a sudden and complete engine failure without any prior warning. There were no warning lights, dashboard alerts, or performance issues that would have indicated an impending mechanical problem. The failure occurred unexpectedly while I was actively driving on a public roadway. After the incident, the vehicle was inspected and diagnosed by a licensed mechanic. The diagnosis determined that an internal engine lifter failed, which subsequently caused damage to the camshaft. This type of failure appears to be the result of an internal mechanical defect rather than any form of neglect or improper maintenance. The abrupt nature of this engine failure created a serious safety hazard. The vehicle suddenly lost the ability to operate normally, forcing me to slow down and stop in active traffic. This unexpected loss of power placed my safety, as well as the safety of other motorists on the road, at significant risk. A critical engine component failing without warning while the vehicle is in operation raises serious concerns about reliability and safety. The vehicle has been properly maintained throughout ownership. All routine maintenance and servicing have been performed by licensed mechanics, and I can provide complete maintenance records documenting this history. At no point prior to this incident were there any signs, warnings, or diagnostic alerts indicating an issue with the engine. The vehicle has already been fully inspected and diagnosed by a licensed mechanic, and the findings are available for review. If necessary, arrangements can be made for the manufacturer or an authorized representative to inspect the vehicle and verify the damage. Given the sudden nature of this failure, the internal engine damage involved, and the safety risk it created while driving, I am requesting that this issue be formally reviewed and addressed by the manufacturer.

My 2020 GMC Sierra Denali diesel with approximately 90,000 miles experienced two separate front suspension failures within a short period of time. The driver side tie rod and wheel hub failed first and required repair. Shortly after, the passenger side front suspension failed in a similar way and the vehicle had to be towed. These failures caused the front wheels to become unstable and created a serious safety concern while driving. Suspension components such as tie rods and hubs should not fail at this mileage under normal driving conditions.

Hi, was driving Vehicle GMC 1500 Denali, vehicle Lost power, all Lites lite up on Dashboard, Vehicle Just lost power and i swerved off Road and sideswiped a Plant Holder on side of Road, damaging side passenger Rear door. I bought the truck to GMC Rvc and they said vehicle Blew Cam shaft and Lifters. I explained to them I'm very concerned for others safety in these Vehicles with the 6.2 Engine. Someone is going to get Killed or even a family. I did look up this vehicle its not listed in Recall, but this vehicle has same engine as ones in Recall. Rvc Gmc issued me a bill for repairs for the amount of $8185.20 and they stated they took 3k off invoice. I did Pay total Invoice....I'm just asking you to please look into this as this is defiantly an issue and this year should be listed on Recall as well.. Thanku for at least looking at this. My cell is [XXX] if you need to reach us...Thx.... INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

At 96,000 miles (3,000 miles after the extended warranty expired), I noticed the "GM tick" more prominent and had more of a metallic sound than it ever did. Upon further investigation, it was found that a collapsed lifter may be the culprit. The truck was brought to the dealer and it was confirmed that the #1 hydraulic lifter had collapsed and needed replacement. This work was approved and tonight, I received a call from Rivard Buick GMC saying that the collapsed lifter also caused significant wear on the camshaft which also now requires replacement. Loss of power on the road poses a significant risk as I carry my children in the vehicle. No warning lamps, messages, or other indicators appeared before or when the issue occurred. The issue was reproduced by the manufacturer/dealer. The dealer Service Manager confirmed that this is extremely common with these trucks with the 6.2L engine and said it was a design flaw due to Dynamic Fuel Management, as well as the oil viscosity recommendation from GM being too low. The year group before and after the 2020 has been recalled along with TSB's issued, however, this group is not part of it. I contacted GM Customer Service (Case [XXX]) and was offered a 10% discount on the repair, being told that this is a "great deal considering the vehicle is out of warranty". GM Customer Service has now resorted to not answering any further questions after several attempts to reach someone. This is also after replacing the 10-speed transmission that was also not part of any recall but that was such an issue that the dealer was only able to source used transmissions rather than new parts. Clearly GM won't make the right decisions to back their products or customers, so NHTSA intervention is necessary. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving approximately 40 MPH, the check engine warning light illuminated. The vehicle was taken to a dealer, where it was diagnosed, and determined that the oil pump solenoid needed to be replaced. The vehicle was repaired, but after the repair was performed, the engine seized. The manufacturer was notified of the failure. The failure mileage was approximately 45,000.