The contact owns a 2021 GMC Sierra 1500. The contact stated that while attempting to start the vehicle, the engine failed to turnover. The vehicle was towed to the residence. The contact stated that the vehicle was inspected and it was determined that the engine had seized. The engine was rebuilt and the vehicle was repaired. The manufacturer was notified of the failure. The contact associated the failure with the federal safety agency Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The failure mileage was 142,767.
2021 GMC Sierra 1500 engine problems
372 complaints (62% of all complaints for this car). Typical mileage when it fails: 58,522.
- owner complaints
- 372
- of this car's complaints
- 62%
- typical mileage
- 58,522
- crashes
- 0
- recalls
- 1
Which part fails
- Engine: crank/camshaft position sensor1
- Cooling system: hoses/lines/piping/fittings1
At what mileage
Complaints by mileage at the time of the problem.
0k-25k
25k-50k
50k-75k
75k-100k
100k-125k
125k-150k
150k-175k
175k-200k
200k+
GMC Sierra 1500 engine problems in other years
Specific symptoms reported on the 2021 GMC Sierra 1500 engine
Phrases found in the owners' own descriptions, so one complaint can mention several symptoms.
Engine failure 115Check engine light 111Loss of power 65Knocking 56Misfire 25Oil consumption 21Stalling 21Won't start 17Overheating 11
Related recalls
Engine and engine cooling: engine: hard parts internal/mechanical
- What is wrong
- General Motors LLC (GM) is recalling certain 2021-2024 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, and Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles equipped with a 6.2L V8 gas engine. The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure.
- Risk
- Engine failure increases the risk of a crash.
- Remedy
- Dealers will inspect the engine, and as necessary, repair or replace the engine. For vehicles that pass inspection, dealers will add higher viscosity oil, install 6 oil fill cap, replace the oil filter, and update the owner's manual. Repairs will be performed free of charge. Owner notification letters were mailed June 18, 2025. Owners may contact Cadillac customer service at 1‑800‑333‑4223, Chevrolet customer service at 1‑800‑222‑1020, or GMC customer service at 1‑800‑462‑8782. GM's number for this recall is N252494000.
Recall number 25V274000 · Recall details
Related investigations
Loss of motive power due to engine failure post recall remedy
On January 16, 2026, the Office of Defects Investigation (ODI) opened Recall Query RQ26001. This investigation was opened to assess the remedy effectiveness of Recall 25V‑274. ODI has received complaints alleging engine failure in vehicles after the recall remedy had been completed, whether that remedy involved an oil viscosity change or a complete engine replacement. General Motors (GM) issued Recall 25V‑274 to address concerns of engine failure in the L87 engines produced between March 1, 2021 and May 31, 2024. GM cited the root cause as a supplier manufacturing and quality issue. GMâs recall remedy for Recall 25V‑274 consisted of two different repairs, either an oil viscosity change or an engine replacement, based on the results of the remedy inspection procedure. ODI continues to receive reports of engine failures after the completion of the recall remedy. To date, ODI has received 499 complaints alleging post-remedy engine failure in vehicles subject to Recall 25V‑274, 473 of which involved an oil viscosity change and 26 a complete engine replacement. Additionally, ODI has received 191 reports of L87 engine failures in engines produced after the production period cited in Recall 25V‑274. GM reported receiving 6,953 complaints of post-remedy engine failure. ODI is opening this Engineering Analysisto continue investigating complaints of post-remedy engine failure. ODI is expanding the scope of this Investigation to include engines produced after the production period cited in the recall. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to
EA26005
Loss of motive power due to engine failure post recall remedy
On January 16, 2026, the Office of Defects Investigation (ODI) opened Recall Query RQ26001. This investigation was opened to assess the remedy effectiveness of Recall 25V‑274. ODI has received complaints alleging engine failure in vehicles after the recall remedy had been completed, whether that remedy involved an oil viscosity change or a complete engine replacement. General Motors (GM) issued Recall 25V‑274 to address concerns of engine failure in the L87 engines produced between March 1, 2021 and May 31, 2024. GM cited the root cause as a supplier manufacturing and quality issue. GMâs recall remedy for Recall 25V‑274 consisted of two different repairs, either an oil viscosity change or an engine replacement, based on the results of the remedy inspection procedure. ODI continues to receive reports of engine failures after the completion of the recall remedy. To date, ODI has received 499 complaints alleging post-remedy engine failure in vehicles subject to Recall 25V‑274, 473 of which involved an oil viscosity change and 26 a complete engine replacement. GM reported receiving 6,953 complaints of post-remedy engine failure. ODI will close this RQ and continue to investigate complaints of post-remedy engine failure for Recall 25V‑274 as part of an Engineering Analysis (EA26005). To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to
RQ26001
Loss of motive power due to engine failure
The Office of Defects Investigation (ODI) has received 1,157 reports of engine bearing failure failures in the L87 6.2L engine produced by General Motors (GM). Of the 1,157 reports received, 173 are outside of the scope of recall 25V‑274. These engines are installed in Model Years (MY) 2019â2024 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2021-2024MY Chevrolet Suburban and Tahoe, GMC Yukon/Yukon XL, and Cadillac Escalade/Escalade ESV vehicles. The subject engine failures were investigated as part of a Preliminary Evaluation (PE25001). GM determined that these engine failures were due to multiple supplier manufacturing and quality issues. GM issued recall 25V‑274 to address the supplier manufacturing and quality issues produced between March 1, 2021, and May 31, 2024. Based on the issuance of recall 25V‑274, the federal safety agency has closed PE25001. ODI continues to receive a significant number of reports of engine failure in vehicles outside the scope of 25V‑274. This presents a potential safety risk that warrants further investigation. ODI is opening this Engineering Analysis (EA) to further evaluate the scope and severity of the potential problem and to fully assess the potential safety-related issues of vehicles built outside the recall scope. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to
EA25007
Loss of motive power due to engine failure
On January 16, 2025, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE25001 after receiving complaints and field reports concerning engine failures in MY2019-2024 GMâs full-size truck and SUV T1XX platform equipped with the L87 6.2L V8 engine. These complainants alleged engine bearing failures resulting in knocking and growling noises from the engineâs bottom end and in some cases more severe consequences such as broken connecting rods leading to engine damage, or engine failure. If the engine fails during vehicle operation, the vehicle will lose propulsion, increasing the risk of a crash. On April 24, 2025, GM issued recall 25V‑274 to address the concern with L87 engines produced between March 1, 2021, and May 31, 2024. GM cited the root cause as a supplier manufacturing and quality issues. GMâs recall remedy will be either an oil change to an oil with a different viscosity or engine replacement depending on the results of the remedy inspection procedure. To date, ODI has received 1,157 allegations of engine bearing failure. GM submitted 55,464 reports in total, with 29,752 unique VINs. ODI continues to receive allegations of L87 engine failures which fall outside of the scope of recall 25V‑274. Based on GMâs recall, ODI will close this PE. the federal safety agency will continue to investigate complaints of engine failure outside the scope of recall 25V‑274 as part ofEngineering Analysis (EA25007). To review the ODI reports cited in the Closing Resume ODI Report Identification Number document, go to
PE25001
What 2021 GMC Sierra 1500 owners say
Most recent owner complaints, unedited.
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 45 MPH, there was an abnormal knocking sound coming from the vehicle. The vehicle started hesitating, and there was a loss of power that became worse over time. Additionally, the “Service Engine” and “Power Train” warning lights were illuminated. The messages “Loss of Steering Assist - Be Alert” and “Service Parking Brake” were displayed. The following day, the vehicle was driven in LIMP Mode to the dealer and was diagnosed with engine failure. The contact stated that there was an ongoing the federal safety agency investigation associated with the 6.2L engines. The failure mileage was approximately 34,000.
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.
I have repeatedly experienced a noticeable exhaust odor inside the cab while operating the vehicle\. The condition is particularly pronounced during cold weather when the vehicle is idling\. Under these circumstances, the exhaust smell inside the passenger compartment is distinct and concerning\. I have taken the vehicle to two separate General Motors dealerships in an effort to identify and resolve this issue\. On both occasions, I was advised that the vehicle was fine\. Despite these visits, the problem remains unresolved, and I continue to experience exhaust fumes inside the cab under the conditions described above\. My concern is that exhaust gases may be entering the passenger compartment, potentially exposing the driver and passengers to harmful emissions, including carbon monoxide\. Because carbon monoxide cannot be detected by smell, the presence of an exhaust odor does not establish whether carbon monoxide is present or at what concentration\. However, the recurring odor warrants a thorough investigation to determine its source and whether a potentially hazardous condition exists\. I am concerned that the issue may not be adequately identified during routine dealership inspections if the vehicle is not evaluated under the specific conditions in which the symptoms occur\. The fact that two dealerships have indicated that the vehicle is operating normally does not resolve my concern, particularly because the symptoms continue to occur\. I am requesting that the federal safety agency review this complaint and determine whether further investigation is warranted into the possibility of exhaust gases entering the passenger compartment of this vehicle\. I would appreciate consideration of whether this condition could represent a safety\-related defect that may affect other vehicles of the same make, model, or model year\. I have made reasonable efforts to address this matter through authorized GM service facilities.
Engine locked up while driving down the road at highway speeds. Lost all power and had to pull to shoulder of road. Was towed to dealership and confirmed engine locked up and covered under special recall. Was looked at a few months back and passed the recall test on engine. No lights or signs of engine failure before failure.
My 2021 GMC 1500 Sierra has the 6.2L motor that has significant known issues with catastrophic engine failure involving the camshaft and lifters. The engine in my truck has suffered the same failure but for some reason my VIN is not included in the recall of nearly 600,000 GMC trucks. I called GMC Customer Service and was told bluntly the recall was VIN specific and I would have to bear the 14,000 dollar repair. This is unacceptable since GMC is under federal investigation for knowingly and negligently manufacturing a flawed motor.
My vehicle fits Special Coverage N252508341in every way, except the dealership tells me that my VIN is not covered. I drive a 2021 GMC Sierra 1500 with approximately 61,000 miles. This weekend a Check Engine Light illuminated with P1010 code. All the symptoms described in Special Coverage N252508341 were exhibited: the vehicle displayed 'Engine Power Reduced', and the electric cooling fans began operating at full output. I have taken the vehicle to Cronin GMC here in Perrysburg and it has been diagnosed with Coolant Control Valve failure that requires replacement. They state that my VIN is not covered by Special Coverage N252508341 and that I must pay full price for the replacement. I am writing to extend this coverage to my vehicle so I can either receive a no-charge repair or seek reimbursement after I pay for the service.
Service light came on because the brake petal would push back when I tried to start it. At times, I had to push down all the way almost to the floor and then it would start. If I eased up slightly or did not push all the way, the truck would hesitate to start. I brought it in to Courtesy GMC of [XXX]. They found metal debris in oil. The car warranty did not want to replace the entire engine as General Motors' bulletin had stated as a corrective solution. They only wanted to replace the camshaft and rocker arms because [XXX] did not tear down the engine to the point of failure. [XXX] stated that they did. After going back and forth with EasyCare (myself and [XXX]) I authorized the repairs EasyCare suggested. XXX, a Service Brake Assist message came on. I brought it to [XXX]. They rectified the issue. XXX,Truck stalled getting off XXX at light. Truck kept turning on and off. I put it in park and was able to turn in on. As I was driving the truck was rocking back and forth as I pressed the gas pedal. I was able to pull into the Super1 Foods parking lot. Trucked stalled halfway into parking lot. After two attempts to turn off and start truck I was able to pull it up all the way to ensure safety. Texted [XXX] at Courtesy. I called the number he sent and a tow truck from Cliff’s Towing and Recovery, LLC retrieved my truck and brought it to Courtesy GMC in [XXX] where it is currently residing. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Loud engine knock, made it to dealer. Dealer confirmed engine failure as defined in the applicable recall. No idea when a replacement can be aquired. Unable to drive anywhere due to design and manufacturinf issues I did not cause.
The contact owns a 2021 GMC Sierra. The contact stated that while driving at 60 MPH, a reduced power mode warning message unexpectedly illuminated, and the vehicle unexpectedly entered limp mode. The contact stated that the temperature gauge indicated a high temperature and the vehicle was overheating during the failure. The vehicle was taken to the dealer, where it was diagnosed that the control valve had failed and needed to be replaced. The vehicle was not repaired. The dealer informed the contact that this was a known failure and escalated the issue to the manufacturer for further assistance. The contact stated that the failure was associated with Technical Service Bulletin (TSB) N252508340 and believed the repair should have been covered under warranty. The manufacturer was made aware of the failure via telephone and website. The contact was also referred to the federal safety agency for further assistance. The approximate failure mileage was 110,900.
Questions about the 2021 GMC Sierra 1500 engine
Does the 2021 GMC Sierra 1500 have engine problems?
Owners have filed 372 complaints about the engine of the 2021 GMC Sierra 1500, 62% of all its complaints, more than any other problem.
At what mileage do 2021 GMC Sierra 1500 engine problems start?
The typical (median) mileage in owner complaints is 58,522 miles.
Was there a recall on the 2021 GMC Sierra 1500 engine?
Yes, 1 recall: 25V274000. Check your VIN to see if your car still needs the free repair.
What year does the GMC Sierra 1500 have bad engine?
The GMC Sierra 1500 model years with the most engine complaints are 2021 (372 complaints), 2019 (335 complaints) and 2022 (270 complaints).
Other 2021 GMC Sierra 1500 problems
Transmission 147Electrical 76Fuel system 42Steering 35Brakes 25Driver assistance 15Body 13Locks 10Suspension 10Acceleration 7Visibility 7Airbags 6Wheels 5Tires 4Seat belts 3Lights 2Seats 1
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