2025 GMC Sierra 1500: engine failure

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 Oct 29, 2026 · Engine · MI

This is a follow up to my recent safety concern on my 2025 GMC Sierra 1500 with the 6.2 engine. Dropped off my vehicle to our GMC service dealer on 10/22/2026 - Oil change and 15K mile check up was getting close. Mileage at drop off was 14,278 and the engine was still making sounds/noise and getting louder. Asked the service advisor to check for metal in the oil or filter. Based on their service review and advisors response, metal was found in the oil filter and engine is ticking. Service department sent information to GM rep for further actions needed. Dealer rep stated that I need a new engine due to this new found issue. Waiting for response from a GM representative at this time. Truck is in my garage at home. I remain very concerned about driving this vehicle at this time. Just called the dealership as I have not heard of any follow up yet. Call went to voice mail of my service advisor. 6.2 Engine is ticking and metal has been found in the filter. Please add this to my original concern on this VIN #.

Filed Oct 29, 2026 · Engine · 64,000 miles · NC

The contact owns a 2025 GMC Sierra 1500. The contact stated that while her husband was driving 10 MPH, the vehicle lost power. The driver turned off the vehicle and attempted to restart the vehicle; however, the vehicle failed to respond. No warning light was illuminated. A dealer was contacted. The vehicle was towed to the dealer where it was diagnosed and determined that the engine needed to be replaced. The engine was replaced and the vehicle was repaired. The contact stated that the engine was replaced twice. The manufacture was notified of the failure and opened a case. The approximate failure mileage was 64,000.

Filed Oct 21, 2026 · Electrical, Engine · TN

The engine locked up and stalled out while driving. GM replaced engine but still experiencing issues. Dealer has admitted that they will likely recall my model year since it is an ongoing and same issues as recalled trucks. I have a vehicle I am not confident in nor safe it since it stalled while driving.

Filed Oct 19, 2026 · Engine · MI

In April 2025, we purchased a new GMC Denali Sierra 1500 Ultimate pickup truck. Concerns – Many of these comments appear in the Dealer Service Reports 1st Service Visit 10/17/25 At our first oil change and scheduled maintenance (10/17/25) with mileage of 5403 miles, during the drop-off I informed the GM Service Advisor of a clicking sound from the engine which I thought might be a fan belt. When I picked up the truck from Service, the Service Adviser informed me that upon startup, a “clatter” type noise was heard, “reminiscent of bad lifters.” The Service Adviser reported that during the mechanic’s test drive, the “clicking noise would get louder with engine speed.” No trouble codes were found after being checked by the MDI. They checked for misfires and a few misfires were found but “not often. At “idle” during this service call, the Left Engine Bank had a “good click/metallic tap to it.” “When the idle was raised, the Right Bank would get loud and had a loud tapping sound.” The oil change did not show any visible metal particles. The GM Service Department recommended a “complete tear-down of the engine for further inspection,” tentatively scheduled in a few weeks, pending Service availability. The Service Adviser stated he would recommend an engine replacement. 2nd Service Visit 10/27/2025 While driving the truck, I noticed that the engine “ticking” had gotten louder, and a Check Engine light had gone on and off. I returned to the Service Department on 10/27/25 (mileage 5807). The Service Department inspected the vehicle and found no “stored DCTS” but found “noise is there for internal engine noise.” The team recommended “tear-down or possible new engine.” Service appointment was set for 11/3/2025 for 5-days. 3rd Service Visit 11/3-7/2025 Service department reported that there were no problems. Vehicle was not under recall..... Scheduling a oil change this week. 14,500 miles.

Filed Sep 8, 2026 · Engine · PA

On XXX my 2025 gmc sierra 6.2L v8 engine experience catastrophic engine failure with no preexisting alerts or warnings. It was towed to Baglier gmc in [XXX] on XXX and is currently awaiting diagnostic evaluation. Upon restarting the vehicle after failure, the engine light did turn on. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 29, 2026 · Engine, Transmission · TX

Engine started knocking at 18k miles and took to dealer and they found metal in the filter and installed a new engine and also replaced the midplate gasket on the valvebody due to a harsh downshift without codes in the system this engine is going on 2k miles and it seems to be fine now but the problem with 6.2 was only supposed to be on the 21-24 models and mine is a 25 model and already had a replaced and nothing from gm was said to extend the warranty on this model and powertrain

Filed Aug 28, 2026 · Acceleration, Engine · LA

I own a 2025 GMC Sierra 1500 Denali equipped with the 6.2L V8 L87 engine, VIN [XXX]. The vehicle had approximately 35,000 miles when the engine experienced a catastrophic engine failure. Prior to/during the failure, the vehicle experienced abnormal engine noise and a loss of power. Multiple warning/alarm lights appeared on the dashboard, including the Check Engine and Traction Control warning lights. The engine failure resulted in a loss of motive power and made the vehicle unsafe to operate. PHONE# [XXX] The sudden loss of engine power while driving created a serious safety hazard because the vehicle could no longer operate normally in traffic and could potentially cause a crash. I am requesting that the federal safety agency document and investigate this engine failure as a potential safety defect involving the GM 6.2L L87 engine. I am also requesting that the federal safety agency determine whether 2025 GMC Sierra 1500 vehicles equipped with this engine should be included in an appropriate safety recall or other corrective action. The vehicle is a 2025 GMC Sierra 1500 Denali with approximately 35,000 miles. The engine failure and warning lights occurred during normal vehicle operation. The vehicle and repair records can be made available for inspection, and I can provide dealer repair orders, diagnostic information, photographs, and other documentation concerning the failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 28, 2026 · Engine · NJ

Confirmed as catastrophic engine failure by dealership. New engine has been ordered.

Filed Aug 24, 2026 · Engine · IL

The 2025 GMC Sierra 1500 with 18,675 miles and the 6.2 gas engine failed during a road trip. I was on my way from [XXX] to [XXX] on the Interstate when about 7 hours in, just outside [XXX]. I was noticing a lack in power when I pulled out of a rest area. The truck would not accelerate over 60mph. I slowed down and as I was pulling off the side of the interstate, the truck died. There was knocking sound as I started to pull over. I attempted to restart the vehicle; it did not restart. I called roadside assistance and the tow truck to myself and the truck into Edwards Chevrolet Cadillac in [XXX]. They diagnosed the issue as spun or bad bearing in the engine, and it would need replaced. They told me that the last 6.2 engine took 60+ days to receive and they were now on backorder, plus they already had a truck in the shop waiting for one. There were no warning indicators on the console, and all my service has been done at GM dealers. The biggest safety issue was being stuck on the side of the interstate with rushing semi's going by. I was also going to be stuck in [XXX] until a resolution was found. I ended up purchasing a new 2026 GMC Denali Ultimate with the 3.0 diesel. It was the closest package that was on my 2025 and I wanted to stay the same, minus the 6.2 engine. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 29, 2026 · Engine · AL

Engine started making a loud knocking noise and it sounded like the engine was about to throw a rod. Turned engine off and called GM. Vehicle was towed to dealership and it was diagnosed with a thrust bearing failure. My truck only had 14k miles on it. To fix the bearing issue, it will need a new engine. GM does not currently have engines to replace the faulty ones so it has sat at the dealership for 3 weeks with No ETA as to when it will be fixed. This is apparently a common problem in the 2025-2026 models LZ0 3 liter diesel. They are still selling these affected vehicles currently, knowing that they may have a problem. GM needs to issue a recall and take these vehicles back.