2024 GMC Sierra 1500: sudden loss of power

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 Oct 26, 2026 · Electrical, Fuel system · KY

My truck has experienced recurring diagnostic trouble code P244B on [XXX], [XXX], and [XXX], 2026. The latest occurrence included a check-engine warning and reduced engine power. On [XXX], at 40,833 miles, Neil Huffman Chevrolet GMC in Frankfort, Kentucky, diagnosed a damaged diesel particulate filter differential-pressure sensor connector. The dealership's written estimate states that the connector had shorted, begun melting, and had broken wires at the back of the connector. I am concerned about the cause of the electrical overheating, the possibility of additional wiring damage, and the risk of unexpected reduced engine power while driving. I have also experienced intermittent transmission-related warnings and communication fault codes, although I do not know whether these problems are related. I understand there are GM technical bulletins addressing wiring-harness damage on certain 3.0L Duramax vehicles. I am not claiming these bulletins establish the cause of my failure, but I would appreciate having my experience evaluated for a possible safety-related defect trend. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 13, 2026 · Engine · 70,172 miles · WI

The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving at 70 MPH, the vehicle unexpectedly started shaking and losing power until it completely stalled. The check engine warning light started flashing, and the warning messages "Service ESC" and "Service Traction Control" were displayed. The vehicle was towed to the dealer. The contact discovered that the engine had previously been replaced by the dealer at 46,370 miles under the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling) under the prior owner; however, the failure recurred. The contact associated the failure with the safety recall. The dealer was contacted regarding the issue. The failure mileage was approximately 70,172.

Filed Sep 17, 2026 · Engine · GA

On 9-5-26 while on interstate 75 going about 75 miles per hour truck started losing propulsion and speed started dropping. No warning light or anything. Navigated over to shoulder turn truck off for about 5-10 minutes and started back. On 9-8-26 on the way from Dr. appt. starting truck up it acted like it didn't want to start but did. Eventually stopped at red light and truck died and wouldn't start. Dash board lighting up and when trying to start the engine would not turn over. No warning light or anything. Truck towed but had to drag on the wrecker due to wheels locked up. On 9-16 GMC advised engine fail and will need replacing at 12,000 miles. VERY UNACCEPTABLE FOR 2024. Truck was bought new in October 2023 with 4 miles. Found out it is a known issue with the 6.2 V8. Be careful. We could have been killed in the flow of traffic and truck losing power with no warning. Couldn't even turn hazard lights on or anything. 18 wheelers coming all around and we trying to navigate to safe spot on the shoulder when we was on the interstate. GMC need to get their stuff together, you are putting people lives is danger. GMC is feeling our anger right now. Who wants a new engine in a $90,000 top of the line truck

Filed Sep 15, 2026 · Engine · MI

I was driving my truck and I had a sudden loss of power. The engine sounded like a rattle of bolts. It was towed to the dealership and they replaced the engine.

Filed Sep 9, 2026 · Electrical, Engine · NJ

While driving on a divided two lane state highway at approximately 60mph my vehicle suffered a catastrophic engine failure causing immediate loss of power in traffic at highway speeds. I had to negotiate highway traffic to steer the vehicle onto a narrow shoulder and continue under reduced power to a location where the vehicle could remain stopped safely. There were no warning signs and no warning lights prior to the issue. The vehicle was towed to Faulkner GMC where it was eventually inspected and determined to be an engine failure consistent with the open recall affecting GM 6.2 L87 V8 engines. A replacement engine was installed under warranty. Additionally, a defective tailgate switch was discovered and replaced. A prior unrelated incident had occurred where the tailgate switch activated on its own lowering my tailgate while the vehicle was in motion. The tailgate lowered onto the tongue jack of a trailer I was towing causing damage to the tailgate. This issue occurred multiple times throughout my ownership of the vehicle until the switch was replaced. GM acknowledged the switch was found to be defective but refused to take responsibility for the damage.

Filed Sep 9, 2026 · Engine, Fuel system · WA

Lifters and camshaft failure, loud clanking, & sudden power loss on the 6.2 motor are the first noticeable signs. Instantly when everything happened check engine light, cruise control, & stabilizer lights flashed. The sudden loss of power forced the vehicle to suddenly slow down forcing my camper into the truck. I was hauling a within weight standerd camper but had difficulty bringing both the truck with the camper to a safe stop. There were no early signs or signal prior to sudden cautostrophic engine failure & all service records have been completed by a GM certified service dealer.

Filed Sep 7, 2026 · Electrical, Engine · NC

My vehicle has experienced repeated and unresolved electrical system failures and unexpected loss of power steering assist. The problem involves multiple warning lights, module communication faults, drivability issues, and simultaneous malfunctions affecting systems including power steering, traction control, transmission, four-wheel drive, and other electronic controls. Repair records, diagnostic information, and videos documenting the failures are available for inspection upon request. The most serious incident occurred on August 23, 2026, when the power steering failed unexpectedly while I was driving. The sudden loss of steering assist made the vehicle difficult to control and nearly resulted in a collision with an oncoming vehicle. The failure created a significant safety risk because it impaired my ability to safely steer and control the vehicle. The condition has occurred multiple times over several months and has resulted in repeated dealership visits. Repairs have included replacement an HVAC controller, but the failures have continued. The vehicle has been inspected multiple times by an authorized dealer, and the manufacturer has been notified through an open support case. As of the most recent repair visit, no confirmed root cause or permanent repair had been identified, and the dealership was still working with engineering support to diagnose the issue. Prior to and during these failures, numerous warning lamps and service messages appeared, including warnings related to power steering, traction control, transmission, four-wheel drive, trailer brake system, steering column lock, and tire monitoring systems. In some incidents, the vehicle entered reduced-performance mode. These warning messages first appeared in November 2025 and have continued intermittently despite multiple repair attempts. The recurring and unresolved loss of power steering assist while driving creates an ongoing risk of crash or injury.

Filed Sep 3, 2026 · Engine · FL

I purchased a 2024 GMC Sierra 1500 Denali Ultimate equipped with the 6.2L V8 engine on XXX. The vehicle currently has approximately 25,000 miles. On XXX, the vehicle underwent the GM recall repair related to the 6.2L engine at Don Mealey Chevrolet. On XXX, approximately nine months after the recall repair, my family and I were traveling on the [XXX] with my two children inside the vehicle when the engine suddenly experienced a major failure. The vehicle became inoperable while we were traveling on the highway and had to be stopped and subsequently transported to Schumacher Buick GMC in [XXX]. The failure occurred unexpectedly while the vehicle was being operated normally. Having an engine failure while traveling on a major highway with my two children in the vehicle created a significant safety concern because of the potential for loss of power and the danger associated with becoming disabled in active highway traffic. GM has subsequently authorized replacement of the engine under warranty. The vehicle remains at the dealership awaiting completion of the engine replacement. I am reporting this failure because the vehicle had previously received the GM recall remedy for the 6.2L engine issue and subsequently experienced a major engine failure at only approximately 25,000 miles. The failure occurred approximately nine months after the recall repair. I am concerned that the previous recall remedy may not have adequately addressed the underlying condition associated with these 6.2L L87 engines. I am requesting that the federal safety agency document this failure as part of its investigation into 6.2L L87 engine failures and evaluate whether the existing recall remedy adequately addresses the safety-related engine failure condition. Vehicle information: * [XXX] GMC [XXX] 1500 Denali Ultimate * 6.2L V8 engine INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 2, 2026 · Engine · CA

After the initial recall inspection was performed, I was informed that my vehicle was not affected. Subsequently, the vehicle experienced a catastrophic engine failure while traveling westbound on [XXX] near [XXX], approximately one mile from [XXX]. While traveling at highway speed, the vehicle suddenly began losing speed and power. I was positioned between two semi-trucks, creating an extremely dangerous situation. At first, I looked to see if I was traveling uphill because of the unexpected loss of speed. I then pressed the accelerator in an attempt to maintain highway speed. The vehicle abruptly downshifted and the engine RPM increased dramatically. Immediately afterward, warnings appeared on the instrument cluster, including “Engine Oil Temperature High” and instructions to pull over and allow the vehicle to cool down. The vehicle continued to lose power, creating a serious risk of collision due to the surrounding highway traffic. The vehicle was subsequently towed to Findlay GMC, where it was inspected and diagnosed with a failed engine. The engine was ultimately replaced. This failure occurred after the vehicle had been inspected under the recall and I had been advised that it was not affected. I am concerned that my vehicle may have been incorrectly excluded from the recall or that the recall does not adequately identify all affected vehicles. The sudden loss of propulsion at highway speed presented a significant safety risk and warrants further investigation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 1, 2026 · Engine · TX

On 06/26/26, I was driving my 2024 GMC Sierra 1500 AT4 with 6.2 engine (Aug. 2024 engine build date) with 27,614 miles down the highway at 60-65mph and my RPMs started jumping and I lost engine power and received this P0016 error message. I was able to coast off the highway at the next exit but this put me and my family at risk. Once I was able to coast into a parking lot, my truck wouldn't start anymore. My dealer picked up my truck and the engine was on backorder and then was replaced and I got the truck back on 08/21/26.

Filed Aug 27, 2026 · Engine · AZ

Driving at highway speed vehicle began making odd engine noises and then lost power, pulled over and power continued to diminish until vehicle was no longer operable.