The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine seized. The contact was unaware of a warning light being illuminated. The contact stated that while attempting to start the vehicle, the vehicle failed to start. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact referenced an unknown engine recall; however, the VIN was not under recall. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to report the failure to the NHTSA Hotline. In addition, the contact was informed that the VIN for the vehicle was a Canadian VIN, and the mileage was displayed in kilometers. The failure mileage was approximately 120,000.

- Libertyville, IL, USA

Heard a ticking noise then check engine light started blinking along with service esc and parking brake. Took it to the dealer and I had a bad lifter again. I was previously repair for lifters under warranty a little over 2 years ago.

- Panama City, FL, USA

On 10/21/2025 as I was traveling on the highway in Kansas at 60 mph, the vehicle lost power and the engine went into limp mode immediately reducing the speed dramatically. Multiple warning lights flashed on the screen. I was able to get the truck to the side of the highway. The vehicle never started again. I was informed by the dealer that the vehicle would need a new engine.

- Lawrence, KS, USA

The engine is knocking and running rough. I took it to Christian Brothers Automotive in Newnan Ga and the advised engine replacement.

- Newnan, GA, USA

I purchased a 2021 GMC Sierra 1500 Denali (VIN: [XXX] ) from J.C. Lewis Ford in Pooler, Georgia. The dealership did not disclose an active federal safety recall (NHTSA Campaign Number: 24V-xxx / GM XXX) related to engine connecting rod and crankshaft defects that can result in sudden engine failure and loss of propulsion. The Blue Certified delivery document they had me sign includes a section requiring disclosure of any open recalls, but they left the recall section blank and checked that all recalls were explained to me. No disclosure of any recall occurred during the sale. The vehicle developed engine problems within days and is currently in GMC service. The nondisclosure put me at risk of driving a vehicle with a known safety defect. I am reporting this as a dealer nondisclosure of a federal safety recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Richmond Hill, GA, USA

The contact's grandson owns a 2021 GMC Sierra 1500. The contact stated that after the vehicle was purchased from a private seller and driven 258 miles, while his grandson was merging off the exit ramp, the engine seized. The low oil pressure warning light was illuminated. The contact stated that the check engine warning light was illuminated prior to the failure. The vehicle was towed to the contact's residence. The contact scanned the vehicle and retrieved DTCs: P0011, P0016, P006DD, and P0521, stored DTCs: P06DD P0011, and permanent DTCs: P0011 and P0016. The engine was replaced by the contact. The local dealer was contacted for parts. No further information was available. The manufacturer was not contacted. The failure mileage was approximately 100,148.

- Alma, KS, USA

I just surpassed my extended warranty (5 year/100,000 miles) by a couple of thousand miles and my coolant control valve has gone out. The problem is so common that the part is on back order for months at a time. GM says that they issued special coverage for 2020-2022 models, but my dealer is telling me that my VIN is not covered. They want to charge me $2,400 to replace it. This is insane. It-??s a very common problem that they know about and it-??s going to almost break me. We need help!

- Paulina, LA, USA

Engine burning oil and blowing white smoke out tail pipes. Have to add oil every 1500 miles or sooner if towing. Has been an issue since first oil change. Vehicle is now at 88057 miles

- Houma, LA, USA

While traveling to work at 75mph, a sudden an unexpected malfunction of internal engine components caused a loss of propulsion.

- Howe, TX, USA

I am an active U.S. Air Force member. My 2021 GMC Sierra 1500 failed GM Recall N252494003 on Sept 29, 2025 (L87 engine loss of propulsion). GM states this defect can cause sudden engine failure and loss of propulsion, increasing crash risk. Despite the confirmed failure, Ocean Cadillac (Miami, FL) told me to keep driving the unsafe vehicle and refused all Courtesy Transportation. The Service Manager admitted in writing that the engine failed, the defect can cause loss of propulsion, and the replacement engine is delayed under GM National Control for up to 3 months -?" yet they still denied me a loaner or rental. His statements contradict the GM documents he attached: -?? GM Bulletin DCS7222 says Courtesy Transportation CAN be provided during L87 recall downtime and dealers MUST consider loaners/rentals. -?? GM FAQ N252494002 says Courtesy Transportation IS available for this recall. -?? GM FAQ lists recall symptoms (check engine light, hesitation, high RPM, reduced power) -?" NOT battery drain. -?? GM states: -??If the engine fails, the vehicle WILL lose propulsion.-?? Ocean Cadillac ignored these rules and put me back on the road in a known unsafe vehicle. As an American manufacturer, GM has a responsibility to protect American drivers. Their failure to follow recall procedures placed me, my family, and other motorists at risk. I request NHTSA investigate whether GM/Ocean Cadillac are complying with recall safety requirements and whether customers are being told to drive unsafe vehicles after confirmed failures.

- Pembroke Pines, FL, USA

I was traveling home from work and lost all power to the vehicle while driving. No warning lights, check engine lights came on. I was able to cross traffic and park it in a business place. I had it towed to a chevy dealership for diagnostic. They said that the timing chain came off and i would need a new engine. I had it towed to a auto mechanic shop for a second opinion and they gave the same result. The vehicle is only 4 years old with 92,000 miles on it. When i lost all power to the vehicle, I did not hear any strange noises.

- Kalispell, MT, USA

Took the vehicle to the dealer because of an engine noise. It had issues with the valves knocking when it had around 1000 miles. I took it in and now the truck has around 67,000 miles and I-??m being told it needs a new engine because of a bent rod in the engine. I was told that I need a new engine. Previously I had a lot of other issues with the front wheel hubs clicking. But, this truck didn-??t even make it to 5 years and now it needs an engine.

- Katy, TX, USA

I own this 21 GMC Sierra with a 6.2L. This vin is not part of your current recall. But my truck is at a dealership waiting on a replacement engine. I was told that the engine locked up in the bay. Not sure if any lights came on before the engine failed, the dealer did not go into that much of detail. The truck is sitting outside waiting on the engine, not sure if gm made then do any failure analysis or just said its a 6.2 were sending an engine.

- Godley, TX, USA

My wife was driving at highway speeds with all are kids when the trucks motor suddenly loss all power all check engine lights illuminated and what I'm assuming had major engine failure causing rod knock.

- Papillion, NE, USA

On [XXX], at approximately 15,873 miles and while on the freeway approximately 30 miles from my home, my GMC Sierra 1500 with the L84 engine experienced a failure of the DFM lifter assembly. This required a significant engine disassembly and the replacement of multiple valvetrain components. This repair was performed at Gold Rush Chevrolet in Auburn, CA, as documented in the enclosed service invoice. GM has issued Technical Service Bulletins and product communications addressing similar lifter failures in Gen V small-block V8 engines with DFM/AFM, including Service Update N212353840, PIP5776, #19-NA-219, and related updates. Industry coverage and owner reports and current Class Action Lawsuits indicate that these failures can recur, even after initial repairs, due to the high cycling frequency of the DFM lifters. Given the nature of the defect and GM-??s documented acknowledgement of the issue, I am requesting that GM extend the powertrain warranty coverage for the engine and related valvetrain components for a period of 10 years,100,000 miles as a goodwill policy adjustment. A warranty extension would ensure customer confidence and protect against the significant cost of a repeat failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Auburn, CA, USA

After having transmission issues which was replaced under warranty, within 300 miles, the engine failed. The vehicle has now been sitting at the dealership since October 7, 2025 waiting for a replacement engine. There is no timeline available for the replacement engine as they are currently backordered. Absolutely ridiculous.

- Mountain Iron, MN, USA

This was the first time I had ever experienced the rear differential locking up at highway speeds in my truck. It was probably the day after I bought the truck. I was going down route one southbound going probably around 60 miles an hour and the wheels locked up and the vehicle felt like it was gonna come to a screeching hole. It felt like I hit something And then the wheels unlocked and it allowed me to keep driving. I thought that I might have hit the cruise control button on the steering wheel by accident and chopped it up to operator error which now I know is one of the most dangerous recall issues I-??ve ever had to experience or indoor. Thank goodness my family was not with me at the time. But these issues continued on for months-??

- Yardley, PA, USA

I was driving at highway speeds probably doing 55 and another vehicle pulled out in front of me forcing me to slow down rapidly. That-??s when my wheels locked up and my vehicles wheels locked up in the middle of the highway. Screeching tires, almost like the vehicle went into park for a second. After about two seconds, I was able to continue driving a highway speed no check engine lights no error codes. It felt like I just hit something nearly gave me a heart attack. My family was in the car. It felt like we all almost died. It was terrifying. This transmission issue recall situation has happened to me more times than I can count. Now it-??s almost a guarantee that if you have to shift too hard too fast it locks up the differential and it is terrifying. Every time.

- Yardley, PA, USA

I just took my 2021 GMC Sierra 1503.0 Duramax diesel into Faulkner Nissan, today 10/18/2025 m, to have that recall fixed. I picked it up from the dealership and drove about 10 miles before it went into limp mode and reduced power mode while I was driving and started to shift very roughly and I-??ve never had any issue like this before they supposedly fix this recall, I think the software patch made it worse in my case. Now my vehicle is throwing a bunch of different transmission error codes, that it has never produced, and it is going into reduced power mode, as I-??m driving and going into limp mode as I-??m driving, which you never has done before And it feels like it-??s stuttering in early gears now and the idle was really rough it didn-??t idle at a specific spot it went from 800 to 1300 back down to 800 when it should-??ve just been idle at 800. I don-??t know what to do. It seems like this recall made the problem worse for me and my truck in this case, I don-??t know what to do and I don-??t know where to go. I hope you guys can help us. Please make GMC take responsibility Before somebody gets killed. If they haven-??t already this issue is extremely DANGEROUS AND I-??M SURE IS DESTROYING THE TRANSMISSION. I don-??t feel comfortable driving my family in my vehicle anymore because of this issue it is terrifying-??.

- Yardley, PA, USA

Dtc code P1098 present related to faulty coolant control valve on 3.0 duramax diesel engiine. This is a known issue with this engine and is supposed to be covered under the 100K mile powertrain warranty. Previously took vehicle into dealership for repair involving replacement of the coolant control valve but was told reprogramming of the ECM was required first step per GM repair bulletin. Reprogramming cost me $195 and was told this was not covered under the 100K powertrain warranty. Now, a few months later, the same issue and dtc code P1098 happened again while driving on freeway at freeway speeds and caused vehicle computer to limit speed of the vehicle which caused hazardous situation in construction zone as was not able to maintain speed of traffic while towing trailer with boat. I also understand that GM has issued special extended warranty related to this coolant control valve in September 2025 which extends the warranty coverage up to 15 years and/or up to 150K miles but I was told at the dealership that my VIN# does not qualify for this extended coverage for some unknown reason?

- Waterford, MI, USA