GMC Complaints

No sound at different times. No way to reset issue. TSB issued May 14, 2026 for known issue. As of July 6, no estimate on repair. Blinkers make no sounds, Onstar can call but you cannot hear them. In event of accident, no communication.

I was driving at normal highway speed. I exited the highway and started to deceleration for an upcoming traffic light. The engine started making a lot of noise. The 6.2L engine has 31k miles on it. Oil changes have been completed at the dealership where I purchased the sierra Denali. I called the dealership and the service writer could hear the engine noise. He asked if I could get it to the dealership which was about 15 miles away. I tried but the truck stopped about 7 miles from the dealership. They told me to call the onstar service and get a tow. The dealership said it will take about six weeks to get a new engine. In the meantime I'm making payments on an eighty thousand dollar vehicle I can't use. Someone needs to hold GM accountable for the lack of urgency in getting this problem fixed!

What component or system failed or malfunctioned, and is it available for inspection upon request? The engine/powertrain failed. The vehicle is a 2025 GMC Sierra 1500 equipped with the 6.2L V8 engine. The engine developed a severe knocking noise and loss of power at approximately 5,545 miles. The vehicle was taken to the GM dealership, where an engine replacement was approved. The failed engine/component may be available for inspection through the dealership or GM, depending on whether it has already been removed or returned to the manufacturer. How was your safety or the safety of others put at risk? The engine failure created a safety concern because the vehicle experienced reduced power/loss of propulsion while being operated. This could have put me and other drivers at risk because a sudden loss of engine power can make it difficult to safely maintain speed, merge, tow, or move the vehicle out of traffic. The issue occurred at very low mileage and without enough warning to prevent the failure. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The problem was confirmed by a GM dealership. The dealer diagnosed the engine failure and GM approved an engine replacement under warranty. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle was inspected by the GM dealership. GM was involved in approving the engine replacement under warranty. To my knowledge, the vehicle has not been inspected by police or insurance representatives. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Prior to the failure, the vehicle developed a severe engine knocking noise and reduced power/lack of power. These symptoms appeared shortly before the engine failure at approximately 5,545 miles. I do not recall any specific warning lamps or messages before the failure, unless the dealership records

The adaptive cruise control has twice unexpectedly applied the brakes with sufficient force to result in a minor whiplash situation of a sore neck. Both times were driving on a two-lane highway traveling between 65-70 mph (cruise control was set a 68 mph) with no vehicles in the lane in front of me. The adaptive cruise control appeared to interpret oncoming traffic as a vehicle in front of me and aggressively applied the brakes, rapidly dropping my speed from 68 mph to the 35 mph range. Brakes were applied with such force that my neck was sore for about two weeks after each incident. My vehicle also has automatic emergency braking (AEB), but I don't believe this system was activated as the warning lamp on the dash and the audible alert was not activated in either situation. These incidents are related to the adaptive cruise control feature, not the AEB system. The dealership has not had an opportunity to inspect the vehicle yet, or any other agencies. In both incidents, no warning lamps or audible alerts were activated.

This is from dealership “found customers concern of engine light is on and ticking noise found cylinder 4 lifters to be collapsed causing the exhaust gasses to be trapped in the cylinder causing the cylinder wall to dry out and leaving scratches on the cylinder wall recommend replacing motor due to this problem at this time”

On July 3,2026 I was driving my 2022 GMC Sierra 1500 on the highway at a speed of 70mph when the front chrome deflector flew off my vehicle. It tore paint off the hood, and also cracked my windshield. I searched online and noticed this had a safety recall for this issue. I see the recall was done in January 2026, AND has failed completely. I still have the service records of previous repair. GM is giving me issues on finding a remedy to fix this.

The contact owns a 2022 Chevrolet Yukon. The contact stated that while driving at an undisclosed speed, an abnormal knocking and ticking sound emanated from the engine before the vehicle stalled. The vehicle was towed to a local dealer, where it was diagnosed with total engine failure, requiring replacement. The vehicle was not yet repaired. The contact stated that the current engine was a replacement engine from a previous failure, which was tested prior to installation but also failed. Additionally, the contact stated after the failure, the transmission could not be shifted into Neutral, forcing the tow operator to drag the vehicle onto the flatbed truck. The manufacturer was not yet notified of the latest failure. The failure mileage was 45,000.

I was driving my family on the highway and my truck completely shut down. The screen flashed a warning and it slowly started decelerating. Thankfully I was able to make it to the shoulder of the road safely. Engine failure was a known safety issue with my model of truck, but I completed the L87 Engine Loss of Propulsion safety recall testing on 9/18/2025 and was assured my engine passed the testing and was not at risk for engine failure.

Complete transmission failure at 82,000 miles. Well maintained vehicle, not used for towing or heavy hauling. Required complete replacement. Traveling at highway speeds and-according to repair facility- valve failure caused transmission to overheat a stripped gears, causing complete failure. Vehicle was unable to shift into any gears and was left inoperable. Required towing assistance and replacement.

Since purchase of my 1500 Sierra 6.2L on 10FEB2021, the vehicle has always appeared to burn an excessive amount of oil which is consistent with GM’s 6.2L engines and has created safety issues leading to sweeping recalls on this engine model from 2021-2024. I have been informed that the engine was consistently down 2+ qts of oil at every recommended oil change (approximately every 5000mi) although GM literature indicated that this level of consumption was usual in their 6.2L engine. In a JAN26 oil change at approximately 35,000mi I was told that my engine was down over 3qts of oil. On 17FEB2026 I took my vehicle into my Chevy/GMC Dealership to request an oil consumption test at ~35, 089mi. On 30JUN2026 I returned to the dealership for my 2000mi check-in, at ~37,800mi, and was informed that my vehicle had failed the consumption test. With over 600,000 vehicles recalled since 2024 in the 6.2L category, my vehicle/VIN has never been associated with a recall. Despite having minimal miles on this engine, I am now financially penalized for repairs because I had just exceeded the initial Powertrain Warranty and my extended warranty would not cover a pre-existing condition. GM’s 6.2L engines have pre-existing issues from the factory and represents a danger to consumers and the driving public because of these failures.