Engine And Engine Cooling Problems of GMC Sierra 1500 - part 2

Three times this has happened. Most recently pulling in drive and jumps out of drive to park with a jerk and stops.

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.

See all problems of the 2024 GMC Sierra 1500 🔎.

I purchased said vehicle with a little over 76,000 miles on xxx from NW Chevrolet, [xxx]. Dealership service the engine on xxx and remained on their lot until it was sold. While driving home, I smelled gas fumes coming into the cabin and the engine was misfiring causing slight hesitation in motor acceleration while adjusting to speed limits and climbing hills. I told management at the dealership about these issues on xxx. My vehicle is currently in the shop to fix the fuel injection system, spark plugs, grounding issues as of xxx to fix the dealerships mistake costing more out of pocket expense. Management will not do anything about it because it was sold (as is) without a warranty which I refused to purchase through finance and interest charges on a car loan. I purchased a 4-year warranty through endurance on xxx with a 30 day wait period before filing a claim. Gm is letting their dealerships advertise and sell problem vehicles with known motor issues to consumers while marking up the sale price. Vehicles should never be sold until gm fixes all motor defects before advertising to the consumer. The consumer is at serious financial risk when getting an auto loan paying on a broken vehicle. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2022 GMC Sierra 1500 🔎.

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.

Rattling, knocking sound from the 6. 2 ltr motor. Dealer verified engine failure, needs to be replace. Engine failed with only 4770 miles. Never made it to the first oil change.

Powertrain issues and a chassis issue that is extremely dangerous. Tailgate on rare occasions falls open by itself. There is a design flaw in the placement of the catalytic converters. The heat is burning up the fluid. I could not believe my eyes when I serviced the transmission. This is another shortcut by gm to save on the extra wiring needed for the oxygen sensors (2)in the converters and the two oxygen sensors downstream of the converters. There is plenty of room for the converters further down by the tail shaft to drive shaft connections. This is gm’s way of being cheap. Here’s the problem. The converters get way too hot. The fill plug for the transmission which is behind a low rent heat shield crumbled into my hands from excessive heat buildup. Gm knows there is a problem with the fluid breaking down. Their bandaid answer is to use mobil 1 fluid instead of the recommended dexron 6. What needs to happen is a safety recall issued for the unwanted tailgate deploying all by itself. There needs to be a redesign in the exhaust system. The transmission (8 speed) has a catalytic converter exactly on both sides and the crossover pipe runs directly under the transmission sump pan. No wonder they are having issues with transmissions burning up. This is a fire hazard !!! with the converters being so close to the exhaust manifolds, a leak from the engine or the transmission would be enough to ignite and possibly kill the occupants. All in the name of saving a few cents in wiring. Myself, I am a retired gm mechanic. I started working at sewell Cadillac in [xxx] in 1975. I have held the title of ase master tech. Cadillac master tech. I have been a gm shop foreman and a gm service and parts director in my career. I retired from federal express as in charge of fleet maintenance and gse(aircraft equipment). I have certifications from mercedes, BMW, Toyota, commander loaders, goodyear, and more. Given the right set of circumstances, it could end very badly. Dangerous truck ! information redacted pursuant to the freedom of inf.

See all problems of the 2020 GMC Sierra 1500 🔎.

I was notified my lifters in my 6. 2 l v8 would need to be inspected for any defects. When I purchased my vehicle from car max here in jackson, ms, I received a notification from the dashboard that the engine oil was low and to add oil. I turned around and took it back to the dealership as soon as possible. This happened on the first day of owner ship with in 5 minutes of driving off from the lot. I car max told me to just add oil and bring them the receipt and they would reimburse me. I chose not to and asked them to service the vehicle to avoid any issues with my warranty or my car max shield warranty. 2,000 miles later the same notification came across the dashboard again. I took it back to car max immediately and they ended up sending it off to my local gm dealership for service. They topped it off with oil after inspecting it for any leaks in the engine. None were discovered. After the 3rd notification about the engine oil level being low after close to 3,000 miles, they serviced the vehicle and put the vehicle under the oil consumption watch. This took place from October 2025 through September 2026. After multiple visits, they informed me they would need to perform further test to see if the lifters were failing and that I would be responsible for the labor fees estimated at around $632. 82. I informed them I have car max’s 150,000 mile warranty. Fidelity insurance company informed me they would need to send an inspector out to the gm dealership. Before this takes place, they would need the vehicle to undergo various tests and I would be responsible for the labor fees. Should the engine components be found worn down. Fidelity would not cover the repairs. Should the engine components be found defective, they would cover the replacement part but not the label. Labor costs would estimate around $2,978. 95. I asked the gm dealership to share this information with me in writing for documentation purposes. I asked for my vehicle to be parked until further notice.

See all problems of the 2021 GMC Sierra 1500 🔎.

I am writing to formally log a safety concern regarding my vehicle’s 6. 2l l87 engine, specifically in relation to the known defects under NHTSA’s ongoing engineering analysis ea25007. The engine seized up while driving in traffic which has a safety impact on the occupants and other drivers. The vehicle was towed to gm and the they noted the the engine has catastrophic internal failure with large metal debris in the engine oil and filter. This is consistent with failures that other gm owners have experienced with gm's l87 engine. The initial recall (recall 25v-274) for a specific manufacturing window (March 1, 2021, to may 31, 2024), the NHTSA launched ea25007 because it continued to receive a flood of complaints from owners whose vehicles fell outside that original recall window. That is me, I am outside that original window. But I am confident that the issue was known by gm and should have been handled several years ago with a wider recall window. Now I was exposed to a safety issue and I am stuck with a large repair bill. I think there is an even broader active investigation ea26005.

See all problems of the 2019 GMC Sierra 1500 🔎.

I am reporting a serious safety concern involving a 2023 GMC Sierra 1500 denali, 6. 2l l87 v8, VIN [xxx]. This vehicle has now experienced two catastrophic powertrain failures at very low mileage. The first catastrophic engine failure occurred at approximately 23,696 miles. The vehicle was taken to a GMC dealer, where the repair documentation states that the engine had suffered significant internal damage, including damage to the #3 connecting rod, a missing connecting-rod bearing, bearing material throughout the engine, and a scored crankshaft. The dealer determined that the engine was seized and required replacement. Gm replaced the engine under warranty with gm engine assembly part number 12740076. The vehicle has now experienced a second catastrophic failure. On [xxx], while traveling approximately 40 mph, experienced grinding, lurching, and knocking, followed by a complete loss of propulsion. The truck would no longer move and had to be towed to a GMC dealer. At the time of the incident, no warning lights or warning messages were observed. The transmission is also suspected to have failed, although the exact cause and extent of the transmission failure have not yet been determined by the dealer. I understand that NHTSA is currently investigating failures involving gm 6. 2l l87 engines, including failures occurring after previous recall remedies and engine replacements. I am therefore requesting that this incident be included in NHTSA’s investigation and considered when evaluating the effectiveness of the existing recall remedy and the safety of replacement l87 engines. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2023 GMC Sierra 1500 🔎.

Catastrophic engine failure due to lifter failure at approximately 51,000 miles driven. This has been confirmed by the dealership and reported/escalated to general motors. The truck is at the dealership for repairs. General motors offered to cover 65% of the repair as a goodwill sign. As the 60k powertrain warranty had expired. This truck has the same components that are covered under the recall for the same model year. However the recall only extends to March 1, 2021 manufacture date. My truck was manufactured a few weeks prior to that so it was not included. Gm refused even discuss this could be potentially due to a recalled issue. Multiple warning lights and error messaged were present on the dash indicating issues when it failed. Additionally, a loud metallic knocking noise was present at speed and idle. Power was significantly reduced and the engine was running very rough.

Coolant control valve failure. This vehicle year is included in a gm bulletin that extends the coolant control valve replacement coverage to 150k miles due to a faulty design. My is valve failing exactly as described in the bulletin and gm will not cover the replacement due to my VIN number. The vehicle randomly goes into reduced power whereby it is prohibited from safely keeping up with traffic. Research shows that there are a significant number of owners in my same situation where gm is denying repair and replacement coverage.

Engine failure.

Lifter failed due to afm system. Cyl 8 misfire due to oil fouling. The onboard computer got confused and would not release the parking brake until repeated attemtps to release it. 5. 3l v8 2020 model year 115250 miles. Isn't this the same problem as the 2021 and newer engines? 8spd transmission. Afm failure. $9k repair.

Xxx 2021 GMC seria 108,339 miles driving home from [xxx] in town and out of nowhere the lights on the dash light up I saw it say adaptive steering and something breaking. There was a lot going on as the steering was rapidly shaking limited breaking while trying to avoid a collision. The engine started a loud knocking sound and sudden smoking out tail pipes. I was able to get the truck stopped turned it off and sat there for a while trying to collect myself. Restarted the truck and slowly drove it to my home 2 miles away. It was flatbed to local gm dealer that quickly diagnosed it saying heavy smoke knocking needs new engine! they won't confirm exactly what the internal engine failure is. Other than its failed. The engine build date is 2020 day 350 my VIN is not currently in the current gm engine recall however it's certain this failure is totally related to gm's engineering design and manufacturing issues. Look deeper into the recall date ranges this failure is clearly a victim. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving 35 mph, the vehicle lost automotive power. There was no warning light illuminated. The contact attempted to restart the vehicle, and the check engine warning light illuminated. The vehicle was towed to an independent mechanic to be diagnosed, and dtc: p0016 was retrieved. The contact was informed that the engine needed to be replaced due to catastrophic engine failure. The manufacturer was notified of the failure. The failure mileage was 113,000.

On 8/31/2026 at approximately 2330 hours I was driving my 6. 2l sierra home. I took a left hand turn and the engine stopped. This happened with zero warning. I attempted to restart the engine after coming to a stop and the starter clicked once and nothing happened. Had it towed to my dealership for service. I was told the engine seized and will need to be replaced. I went through the recall process earlier where I was told my engine passed inspection and the oil was replaced with heavier weight oil and I was told it was good to go.

My truck has the same issues for the transmission and engine problems I have taken it to 4 dealerships and they all say the same thing. The first one I spent about 3 hours there and they changed the 20 oil to the 40 oil and said that will fix the issues but it hasn't I called GMC to report this and they sent me to the others but they said it's been looked at and I know one of them didn't do anything to see the issue. GMC called the other day and I told them I will let the engine locked up or the transmission keep doing the same thing and they'll have to fix the issue then. I do have 109000 miles on it but thus issue has been going on for 4 years they said I have 150000 miles for the issue but I do t think that is right. I paid them cash money for the truck when I bought it.

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 NHTSA 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).

2024 vehicle is part of the massive GMC 6. 2l engine recall. The vehicle was called into the dealership on 1/6/2026 (10,437 miles / 320. 9 engine hours) for recall evaluation. Testing indicated vehicle was not a candidate for a new motor so oil and oil filter were changed to 0w-40 and I was sent on my way. Vehicle started a tapping noise at idle. Dealer advised the next week was the soonest I could be seen so I set up an appointment for Monday 8/31/2026 . I used the vehicle on Saturday [xxx] and while returning home it began making a racket emitting all types of terrible noises. I was only a few miles from the dealer so I limped into the dealship and left the vehicle on their lot. I spoke to the dealership on Monday 8/31/26 and was advised the vehicle would be evaluated later that day. I spoke to the dealership on Tuesday 9/1/26 and was advised the 6. 2l engine had failed (13,591 miles) and parts had been ordered. Dealer advised it would probably be 6 - 8 weeks to get the truck returned. I am a trailer boater and also pull a trailer with a side by side. These activities are why I own a truck. Dealer advised I could get a loaner vehicle but that it was illegal to tow a trailer in illinois with dealer plates. I ended up trading the vehicle for a new truck and suffered a large unplanned expense ( $20,537) as a result. Since the vehicle had failed and was not driveable it was impossible for me to go elsewhere to trade in this vehicle to a competitor. As a result of the failure I feel I was held hostage to buy another GMC. The vehicle did not show any abnormal gage readings or dispaly any warnings. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

2026 GMC sierra slt with 3. 0 duramax diesel engine. While driving down the road with the cruise set to 55 mph on 8/29/26, the engine started to run rough. I slowed down, but this did not seem to help; I sped up, and the problem persisted no matter what I did. Service traction control and service esc displayed on the dash. I drove to the dealership; their service department was closed because it was Saturday. I took my salesman for a ride so he could witness the issue firsthand. He confirmed something was not right, and they put me into a loaner vehicle. The truck has 848 miles on it. Service diagnosed it as a fuel issue in cylinder 2, replaced the injector, but the issue did not go away. Gm tac team advised replacing the motor; that is what I am currently waiting on. The dealer has the motor and is awaiting the install.

Driving on the highway lost proportion/acceleration, loud knocking coming from the engine.

Driving approximately 75mph on a local highway, my engine shut down with no warning, the screen said to shift into neutral to restart but nothing happened so I was stranded along the side of the highway and had to wait 2hrs for a tow truck in the middle of the night and the engine is currently locked up.

Was driving the vehicle and started making a loud knocking noise and had a loss of power.

I am the owner of a 2019 GMC Sierra 1500 4wd equipped with the 6. 2l l87 v8, VIN [xxx], currently at 177,271 miles. On [add date] while driving 40-45 mph westbound on [xxx] near xxx in [xxx], in a school zone, the engine suffered sudden catastrophic internal failure with complete loss of propulsion and would not restart. No prior warning lights or low oil pressure warning. Vehicle required tow from school zone. GMC dealer inspected and verified catastrophic internal failure. Dealer stated verbally failure is either camshaft broken in half or timing chain sprocket/pulley broken off or loose causing timing chain to come off. Timing cover was not removed to confirm. Dealer stated engine is not repairable and quoted $13,500 for new engine replacement only. I have copies of the work order and the dealer's written statement verifying internal failure and replacement recommendation. Engine and vehicle have been retained. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Catastrophic engine failure. A 2026 GMC sierra with only 7360 miles had engine failure while driving at 45 miles per hour which resulted in no power from the engine to assist in getting the truck off the road and stopped safely out of the road. In my case, it happened late at night so traffic wasn't an issue. I was just stranded in a dark, rural area late at night. If this happens to someone in traffic, the results may be much different from mine. After this incident, I learned that this is not uncommon and many trucks/suvs with the gm 6. 2l engine have failed in the same or a similar manners and earlier models have been recalled for the same issue.

I received a notice months ago for possible engine problems. My dealer checked it out and everything was good except for changing oil from 0w-20 to 0w-40. I was in atlanta, GA on 8/26 and by the time I got home on 8/27, engine was knocking. I barely made it home. The dealer has had the truck since. They said I have to have a new engine. No idea when they will get one inn or when I will get my truck back. I opened a claim with gm (case #108927907). Gm basically offered no assistance, help, etc. I even tried to trade the truck back to my local gm dealership for another truck and they wouldn't offer enough on trade inn (says they wouldn't be able to sell it), gm corporate wouldn't offer buy back, loyalty program money, etc. As they claim it's under a recall. I have never received anything about a recall for the engine. Local Ford or Toyota dealerships will not even consider taking it in on a trade after new engine, says they cannot sell because of engine issue with 6. 2l engine. So I'm stuck with a truck that I cannot sell or trade and is now worthless. I'm sure the new engine will fail as well.

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.

My wife and I were driving on the highway going slightly uphill. I pushed the pedal a bit because the power wasn't keeping speed. It continues to not maintain so pushed throttle further and the truck stalled. We traversed 3 lanes to get to the shoulder. When I stoped I tried to restart but the car wouldn't turn over but all electrical were working. We were on the shoulder for over and hour on a main highway. We had aaa tow it to the dealership where they confirmed the engine was seized and will be ordering parts. The car is still available upon request. Our safety was at risk from loosing power on the interstate and sitting on the shoulder is very dangerous. I didn't receive any warning lights prior to this occuring. The truck did undergo the peko test and passed and added new oil viscosity. It had roughly 55k miles on it. Always changed the oil before it hit 0% oil life as told by dealerships.

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

See all problems of the 2025 GMC Sierra 1500 🔎.

Engine shut off. It did restart after placing it in park. I did own a 2022 sierra denali and the motor failed on that vehicle. I swapped out to the 2025 to get away from what I thought was a problem on that vehicle and now learning this is an inherent problem with the 6. 2l motors that include this year. As a consumer, I am very infuriated that the problem has been in place for years and still is today. The dod system in these motors is also a problem and will eventually rear it's head out of warranty. You can go purchase a dod delete kit and pay someone to remove and install the kit but at an additional 2500 in expense for parts and labor. This needs to be addressed!.

Check engine light came on my vehicle (104,000/mi) and fans came on while truck was off. Took to dealership and techs diagnosed vehicle as having bad "coolant flow control valve". Dealership ran VIN check as there is a gm "extended special coverage program" n252508341 for the lm2 motor, which my vehicle has. However, n252508341 only applies to vehicles in CA. The dealership did not cover my repair. I filed a complaint with gm who denied it due to the program being only applicable to CA trucks. I was advised to file a complaint with NHTSA as the only avenue with recourse. I would like if NHTSA intervened and made gm honor the program in all 50 states and I be offered a refund for the $2500. 00 repair I had to pay for. Thank you.

Rocker arms replacement at 5,000 miles on my truck. Palm harbor tasca GMC.

This engine has used more than 2 quarts of oil since purchased in November of 2025. It has 12,000 miles on it. The exhaust pipes are covered in black soot from oil burn. It scares me to drive it, $87,000 retail vehicle worth about nothing with a bad engine. Terrible.

Engine blew on a 2026 GMC at4x with the 6. 2 motor. Has been inspected and confirmed by dealership. No warning on failure, was passing a car when power was lost and warning system said restart engine.

Truck milage at the time of engine failure was 9,101. Well past the break in period for towing. We were towing a car trailer 2,000 pounds less the max towing capacity for the truck and going less than the posted speed limit. The truck was also in tow haul mode. The truck dash flashed oiled heating hot. We tried to pull over on the highway then the truck lost all power and overheated. Our trailer was not all the way off the highway, so a wy state trooper pulled behind us and kept his lights flashing for 3 hours until a tow truck came. Truck could not be placed in neutral, so it had to be dragged onto the flat bed ramp of the tow truck. Truck was towed to the gillette wy GMC dealership that same day. On Monday we were informed that the engine failed and needed to be totally replaced. The gm dealer cannot tell us how long it will take to get the new engine or how long we will be without the truck. This is the 6. 2 v8 which gm assured buyer's of 2026 vehicles that the engine failures reported on previous year vehicles had been rectified on the new models. Less than 10,000 and the engine failed.