GMC Sierra 1500 engine failure problems

Filed Nov 4, 2026 · Engine · LA

I am filing a safety complaint regarding my 2022 GMC Sierra 1500 Limited Denali equipped with the 6.2L L87 V8 engine. My vehicle has developed a persistent engine knocking noise that becomes more noticeable as the engine reaches operating temperature. The knocking continues despite completion of the applicable engine recall work. I am concerned that this condition may be related to the premature internal engine failures associated with the GM 6.2L L87 engine. The continued knocking raises concerns about a possible connecting rod bearing or other internal engine component failure. A sudden engine failure while driving could cause an unexpected loss of propulsion, creating a serious safety hazard, particularly on highways or in heavy traffic. I am requesting that the federal safety agency investigate whether the completed recall remedy adequately addresses vehicles that continue experiencing abnormal engine knocking and potential internal engine damage. The engine remains installed in the vehicle and is available for inspection. I am requesting further investigation into this safety concern.

Filed Nov 4, 2026 · Engine · WY

**Subject: Complete Engine Seizure After GM Recall Remedy – 2024 GMC Sierra Denali 1500, 6\.2L V8** I am reporting a catastrophic engine failure involving my 2024 GMC Sierra Denali 1500 equipped with the 6\.2\-liter L87 V8 engine\. At an earlier date, my vehicle underwent GM safety recall 25V274\. The dealership performed the required inspection, changed the engine oil to 0W\-40, and installed the replacement 0W\-40 oil\-fill cap\. The truck was returned to service\. On October 31, 2026, I experienced an unexpected engine shutdown while driving\. The instrument cluster displayed “Please Restart Engine\.” I subsequently brought the truck to a GMC dealership for inspection\. The dealership reported finding nothing wrong and released the vehicle back to me\. On November 3, 2026, while driving home from that inspection, I attempted to pass another vehicle\. While occupying the passing lane, my engine suddenly failed and seized without warning\. The truck lost all engine power and began coasting\. I was forced to maneuver the disabled vehicle off the roadway and into a ditch\. I contacted OnStar roadside assistance, which located my vehicle and dispatched a tow truck\. The vehicle was transported back to the dealership, where it remains\. This engine failure occurred after completion of GM’s official recall remedy and immediately following an additional dealership inspection that found no problems\. I believe this incident warrants investigation under the federal safety agency Engineering Analysis EA26005, which concerns L87 engine failures following recall repairs\. The sudden loss of propulsion during a passing maneuver created a serious collision hazard\. I request that the federal safety agency investigate this failure and evaluate the effectiveness of GM’s recall remedy\. **Vehicle:** 2024 GMC Sierra Denali 1500 **Engine:** 6\.2L L87 V8 **Mileage at failure:** 40,035 **Final failure date:** November 3 2026

Filed Nov 2, 2026 · Transmission · LA

I am submitting this complaint to bring attention to a potential widespread engine defect involving GM's 6.2L engines, specifically the use of replacement crankshaft Part Number 12732518 in engines that were not originally equipped with the L87 engine. Approximately one year ago, I completed a second engine replacement on my 2017 GMC Sierra equipped with the 6.2L L86 engine. My original rebuilt engine failed after GM supplied a replacement crankshaft that was determined to be out of specification. Following that failure, I had to go through the expense and labor of rebuilding the engine a second time. The concern is that GM discontinued the original L86 crankshaft, Part Number 12623492, and supplied Part Number 12732518 as its replacement. My understanding is that Part Number 12732518 is also used in the L87 6.2L engines that are currently experiencing widespread engine failures and have drawn the federal safety agency's attention. After installing the replacement crankshaft, my L86 engine experienced a failure consistent with the failures being reported in L87-equipped vehicles. This raises a serious concern that the replacement crankshaft may share the same underlying defect or contribute to the same failure mechanism affecting the L87 engines. I am resubmitting this complaint in light of the federal safety agency's recent efforts to obtain additional information from General Motors regarding the 6.2L engine failures. I believe this information is important to the investigation because the potential defect may not be limited to vehicles originally manufactured with the L87 engine. I strongly urge the federal safety agency to investigate whether GM's replacement crankshaft, Part Number 12732518, creates the same engine failure risk when installed in L86 engines. Any investigation, recall, or corrective action should consider not only vehicles originally equipped with the L87 engine but also vehicles that received replacement engines or replacement crankshafts Part Number 12732518.

Filed Nov 2, 2026 · Engine · CO

Information related to GMC 25V274 recall for 2023 GMC Sierra 1500 6.2L. Recall oil change inspection and change of oil to higher viscosity performed summer of 2025 (prior to my ownership). On May 17, 2026 the Truck lost engine power without warning and would not start again. Fortunately I was on a road and location where I could coast into a parking lot, but again the vehicle provided no advanced warning of any issue. Towed truck to dealership and determined that exact engine problem noted in recall had indeed occurred to engine. So GMC recall efforts to inspect and change oil had NO effect on the engine defect. Engine was replaced.

Filed Nov 2, 2026 · Electrical, Engine · NY

Vehicle is a 2025 Sierra 1500 Elevation and has made a rattling noise since purchase in May 2025. Radio had electrical issues and required full replacement. Two weeks ago, while driving home on the thruway, the vehicle began to shake violently and display critical warning errors on the infotainment system, locking up and slowing down. Once I pulled over and turned the vehicle off, it would not turn back on. Towed to dealership, where I was told it was a sensor issue that could be fixed the same day. A week later, I was told there was a bent valve that required repair. It has now been two full weeks with no updates on what's wrong with the vehicle or how long it will be under repair, but based on similar complaints, it appears that it will need a new engine since this is a known recurring issue with this model vehicle. This was a massive safety risk to myself and my children if I had not been able to slow down and maneuver the vehicle off the road when it died.

Filed Nov 2, 2026 · Engine · MD

Was about 1 and a half hours into my 8 hour trip home, when I started to hear a clanging sound coming from my engine after I passed a slow moving RV. The truck ran for about 20 additional minutes when it lost power and shut off. Mileage was at a little over 16,000 miles. No warning lamps, messages or other symptoms of the problem prior to the failure. I was fortunate to be pulling into a parking lot when it shut down, GMC roadside assistance had my truck towed to a GMC dealer where it was determined the engine was blown. They replaced the engine.

Filed Nov 1, 2026 · Engine · UT

Catastrophic Engine Failure/Engine Seized at Highway Speed We were driving on a two lane highway at approximately 55 mph. All of a sudden pressing the gas pedal did nothing and after a few seconds the truck died. I was able to move over a foot or two but there was really not much shoulder. We were blocking traffic. I tried to call for help but had no service and making an emergency call would not work either. I had just started to walk down the highway until I got service when a sheriff's deputy pulled up behind us to help. Thankfully no one was hurt. There were no warning lights or sounds on my dash. The only thing the truck said was to shift to Neutral to restart which of course wouldn't work. The only other indication of what had happened was the temperature gauge was as hot as it would get. When we popped the hood the coolant was boiling and spewing out of the relief valve and the oil was completely empty. My oil was full before we left. My engine had siezed. The dealership won't tear down the engine to find the specific cause becasue it's too costly. It is still sitting at rhe dealership now.

Filed Nov 1, 2026 · Engine · UT

Catastrophic Engine Failure/Engine Seized at Highway Speed We were driving on a two lane highway at approximately 55 mph. We had just left home and only gone 20 miles. All of a sudden pressing the gas pedal did nothing and after a few seconds the truck died. I was able to move over a foot or two but there was really not much shoulder. We were blocking traffic. I tried to call for help but had no service and making an emergency call would not work either. I had just started to walk down the highway until I got service when a sheriff's deputy pulled up behind us to help. Thankfully no one was hurt. There were no warning lights or sounds on my dash. The only thing the truck said was to shift to Neutral to restart which of course wouldn't work. The only other indication of what had happened was the temperature gauge was as hot as it would get. When we popped the hood the coolant was boiling and spewing out of the relief valve and the oil was completely empty. My oil was full before we left. My engine had siezed. The dealership won't tear down the engine to find the specific cause becasue it's too costly. It is still sitting at rhe dealership now.

Filed Nov 1, 2026 · Engine, Transmission · FL

At three years old with 37,000 miles on it, the engine started ticking loudly consuming oil when I went to look it up. I saw there was a recall. Nobody had notified me about the recall. The technician said it failed their diagnostic test and I would be getting a new engine. Nine weeks later, I get a new engine. One year later at 51,000 miles the transmission failed.

Filed Oct 30, 2026 · Engine · MI

This truck has the 6.2L power train and the engine failed and needed to be replaced at approximately 70,000 miles. After replacement around 80,000 miles I then needed to have the water pump replaced because it failed as well.