GMC Sierra 1500 grinding brakes problems

Filed Oct 15, 2026 · Brakes, Engine · TX

On 10/15/2026 I was making a slow right-hand turn up a slight incline into a parking lot when the vehicle braked very hard and the transmission made a grinding noise. I looked at the dashboard, and it was showing that the truck shifted into park while I was driving. The electronic brake engaged as well. I tried putting the truck back into drive, but it would not go into drive. On the dash there was a Service Transmission warning. The push to start engine button still had the green LED on as if the vehicle was running. I pushed the start engine button and the engine started (I didn't realize until now that the engine had shut off). At this point the truck would shift into drive. Another point of note is that I had turned off the Auto Stop feature. I do this every time I start my trip. The truck will be looked at on 10/16/2026 by the dealership. I did report the problem to the service department of the dealership. This incident was the first time it ever happened and there was no warning.

Filed Oct 6, 2026 · Driver assistance, Transmission · OH · fire

I was driving at 70 mph on the highway. I heard clunk and then rattling and saw smoke while losing power. Check 4wd warning illuminated. Came to stop in busy traffic and where I first parked on shoulder, saw shoulder of roadway smoking and on fire. I pulled forward 100 or so feet slowly while hearing more grinding rattling cranking. Came to stop. Fire dept arrived and extinguished roadside blaze. Called towtruck and had towed to [XXX] in [XXX]. 75k miles. No warning just catastrophic failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 23, 2026 · Engine, Transmission · TX

While turning right and at a slight incline the truck engine turned off, the transmission made a grinding noise, the truck went into neutral and the dash stayed “Press Start Button”. This is the second time this has happened within 5000 miles of the struck being purchased. Several others have reported the exact same issue on Facebook forums.

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 Aug 28, 2026 · Engine · MI

I had the L87 recall completed, and the vehicle passed inspection. The dealership completed the required protocol and replaced the engine oil with 0W-40. Approximately 6,000 miles later, while traveling at about 75 mph and six hours from home, I experienced a brief loss of power followed by an immediate return of power. My wife and I noticed it but, with no warning lights or alerts, continued driving while monitoring the vehicle. About 10 miles later, we began hearing a faint squealing noise that progressively became worse. I was able to exit the highway safely, but once I came to a complete stop, the engine shut off and would not restart. I had the vehicle towed to the nearest dealership, where it was determined that I had suffered a catastrophic engine failure. No loaner vehicle was available, leaving my family stranded six hours from home with an inoperable vehicle. It took approximately seven to eight weeks for the repair to be completed. When I received the vehicle back, I immediately noticed something still was not right. At around 40 mph and 1,000 RPM, the truck would shudder or hesitate. My local dealership diagnosed a poor spark plug connection on cylinder #3, which was causing arcing and a misfire. After the connection was repaired, the issue was resolved. My local dealership is currently working with the repairing dealership to address several minor workmanship issues, including wire clips, fittings, and missing bolts. This entire event was unexpected. There were no warning lights, alerts, or unusual noises before the initial loss of power. The only indication of a problem was the sudden power loss followed shortly thereafter by a horrific screeching noise. Thankfully, I was able to safely exit the highway and bring the vehicle to a stop. Considering I was traveling at 75 mph, the situation could have been much worse.

Filed Aug 25, 2026 · Engine, Transmission · MO

For close to one year, there feels like a catch, grind, stall, or slight shake, mostly while the vehicle is shifting gears, made worse or noticed more by higher speeds like driving on the highway vs. slow city streets. It's difficult to explain or assess so not sure if it is the engine or transmission. With the open recall from GMC on some vehicles with the same engine as mine it is concerning that maybe it should have been included.

Filed Jul 8, 2026 · Engine · IA

Catastrophic engine failure while traveling 40 mph. Dealership diagnosed as cylinder walls being scorched and rods blown through. No warning signs existed - just had a loud thud before the check engine light started flashing and grinding sound started coming from engine.

Filed Jun 28, 2026 · Engine · PA

My motor has a catastrophic failure. Started sputtering and Squealing.

Filed Jun 23, 2026 · Engine · MI

While driving, the vehicle experienced a sudden and momentary loss of power, similar to briefly applying the brakes, after which power resumed. This was followed by a progressively louder squealing noise. I pulled over to investigate, at which point the engine shut off and a low oil pressure warning appeared on the dashboard. The vehicle would not restart. The vehicle was then towed to a dealership, where initial inspection suggested the issue may be related to the L87 recall involving the crankshaft bearing.

Filed Jun 17, 2026 · Engine, Fuel system · MI

While driving my vehicle, the engine and transmission lost power and the check engine light came on. The vehicle went into limp mode and engine propulsion was limited. Had I been traveling at a faster speed, this would have been very unsafe. After coming to a stop, placing the transmission in reverse did not move the vehicle and there was a grinding noise. I was able to savely move forward in limp mode, but the shifting was harsh. I was able to find an empty parking lot to safely park. The truck was towed to Jim Winter dealership in Jackson MI for inspection.