2023 GMC Sierra 1500: grinding or squealing brakes

Filed Sep 2, 2026 · Engine, Transmission · PA

I am reporting a serious safety concern involving a 2023 GMC Sierra 1500 Denali, 6.2L L87 V8, VIN [XXX]. This vehicle has now experienced two catastrophic powertrain failures at very low mileage. The first catastrophic engine failure occurred at approximately 23,696 miles. The vehicle was taken to a GMC dealer, where the repair documentation states that the engine had suffered significant internal damage, including damage to the #3 connecting rod, a missing connecting-rod bearing, bearing material throughout the engine, and a scored crankshaft. The dealer determined that the engine was seized and required replacement. GM replaced the engine under warranty with GM engine assembly part number 12740076. The vehicle has now experienced a second catastrophic failure. On [XXX], while traveling approximately 40 mph, experienced grinding, lurching, and knocking, followed by a complete loss of propulsion. The truck would no longer move and had to be towed to a GMC dealer. At the time of the incident, no warning lights or warning messages were observed. The transmission is also suspected to have failed, although the exact cause and extent of the transmission failure have not yet been determined by the dealer. I understand that the federal safety agency is currently investigating failures involving GM 6.2L L87 engines, including failures occurring after previous recall remedies and engine replacements. I am therefore requesting that this incident be included in the federal safety agency’s investigation and considered when evaluating the effectiveness of the existing recall remedy and the safety of replacement L87 engines. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 19, 2026 · Engine · VA

After completion of recall repair, changing oil weight from 0w20 to 0w40, I encountered loud squealing and knocking sounds from the engine bay. As catastrophic failure has been reported the vehicle was immediately taken to the closest GM dealership, Southern Chevrolet of Chesapeake, VA.

Filed Apr 13, 2026 · Transmission · MN

I was driving down the road at 55 mph on 4/12/2026 and had let off the gas for a 45 mph zone when I experienced a violent downshift of the transmission that squealed the tires momentarily and felt like someone had hit me from behind. It startled me and caused me to lower my speed down to 20 mph. I continued driving to my destination and when I let off of the gas doing 45 mph for a slight curve I had another violent downshift that felt again like someone hit me from behind. I contacted a GMC dealer on 4/13.2026 to see if there was a recall on the transmission that I wasn't seeing online and was told no. I described what I experienced to their service department and was told to flush out the transmission fluid and replace the filter. I did experience another bad downshift at a slower speed (about 25 mph) on 4/13/2026. There wasn't any warnings or lights that came on when these three incidents occurred. When looking online I did see there was a similar recall for 2020-2022 GMC Sierra's where customers were experiencing similar violent transmission downshifts and am wondering if this issue is affecting more than just those three model years.

Filed Sep 29, 2025 · Transmission, Wheels · NC

At 12,018 miles on my 2024 gmc sierra 1500 I experienced a rear wheel lock up. I have 4wheel drive capability but I had the truck in rear wheel drive only. Thankfully I was not going fast at the time. I was going between 35-45 mph when experiencing the lock up. As I was going down a straight away, I experienced a rear wheel lock up of my 10L80 transmission. My tires were squealing like crazy. I pulled off onto the side of the road. After shifting to reverse and then park and then drive the problem corrected itself. When I brought it into the dealership, they could not find anything wrong with it. Additionally my trucks software was up to date and not lacking any updates. I don’t drive this truck very far and only drive about 150 miles a week. A rear wheel lock up of this magnitude at this low of miles is concerning. I’m not rough on the truck by any means. It’s more so a family vehicle than a hauler. I have got the truck serviced 3 times since I bought it for regular maintenance so that’s not an issue either. There were no warning indicators that this problem was occurring when I experienced the rear wheel lock up. This could have resulted in a collision with vehicles around me if I had not been aware of what was occurring.

Filed Jun 5, 2025 · Engine · TX

On June 1 my 2023 gmc sierra 1500 6.2 began making a grinding and knocking sound on the engine no previous warning or symptoms. I believe it's a problem related to the engine recall so on June 2nd I took my vehicle to the dealership Brown Chevrolet of Eagle Pass TX where I was told that it would be about two weeks for them to get to it.

Filed Apr 30, 2025 · Engine, Transmission · VA

I was driving down the highway on cruise control and all of the sudden i heard a squeal, banging noise with no power to accelerate so i pulled over to the side of the road and the engine said low oil pressure and shut down and would not restart. Multiple vehicles swerved to avoid hitting my vehicle creating a safety incident with possible injury and death. No symptoms prior to the failure and vehicle was maintained according to GMC specifications at the dealer with oil changes and tire rotations. Dealer has confirmed engine needs to be replaced but after several weeks they say they are unable to replace the engine because no parts are available and no estimated repair date. This is completely unacceptable and not a timely repair. I am without a truck and still paying for the loan of the truck with interest through GM financial.

Filed Mar 27, 2025 · Transmission, Wheels · ID

I was driving at approximately 25-30 MPH, accelerating from a stop light and I felt a clunk, heard a grinding noise and my back wheels locked up. It was snowy/icy conditions so the back end of my pick-up slid out to the right a little bit before the wheels unlocked and I was able to regain control. I could have slid off the road or into another vehicle had the wheels remained locked. The computer system then alerted me to a transmission issue and to reduce speed immediately and call for service. The pickup was then unable to shift out of 1st gear. The vehicle has been towed to a dealer and I have been informed the valve body in the transmission has to be replaced which is 8-12 weeks backorder.

Filed Mar 6, 2025 · Electrical, Engine · FL

On the highway, the engine suddenly stopped working. Everything turned black. While driving, the screen turned back on but the motor did not start again. I pressed the breaks and the start button to turn the engine back on, while still driving on the highway. It turned back on but then stopped again before I had time to pull to the side of the road. I did the same again and got to bring the car to the side of the highway. It started and stopped several times. I got it to run again so I exited the highway. It turned off again once I was off the highway. I got to drive it slowly to the dealer. He said it had never happened (which is untrue, I found out it is a recurring problem on the GM 6.2 liter). I had brought the car for service to the same dealership about a week prior to the incident. At that time, I told the dealer that the motor was making subtle weird noises. They serviced the car and gave it back to me stating that everything was ok and that nothing showed on their computer. When I picked up the car after the shutting off incident, I was told that their system showed prior issues but that nothing needed to be done since it was not detecting any problem at the time of pick up. About a week after I picked up my truck (after the shutting off issue was supposed to have been taken care of), I returned because I was still noticing the noise. While on a test drive with a GM mechanic, the motor suddenly started making very loud clicking and squeaking noises. He told me to stop right away. The manager at the dealership told me I would get a new motor because there was a recuring issue with the GM 6.2l. After a week, he said only some parts would be changed and that GM would not replace the whole motor. I told him I did not feel safe driving the truck and he said GM decides what to replace not me. I read online that the motor and all oil filters, ducts etc need to be replaced to avoid debris and future problems. No warning light ever went on. Terrifying experience.