2020 GMC SIERRA 1500

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving on several occasions at various speeds, the vehicle started shaking and slipped in and out of gear, with the message "Idle Transmission" displayed. The vehicle was pulled over and shifted into park(P) and then to drive(D). There was a loud banging sound coming from the rear of the vehicle. The vehicle was towed to an independent mechanic, where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be repaired. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 80,000.

My engine started knocking horribly, I need to get a proper diagnosis but cannot afford to have a shop look at it. I have been building engines my entire life and am certain the rod bearings have failed. The engine has a distinct knock under acceleration, you can hear it clearly when pulling away from a stop sign for example.

The contact owns a 2020 GMC Sierra 1500. The contact stated that the vehicle made an abnormal sound while idling. There was no warning light illuminated. The vehicle was taken to the dealer, where the engine was disassembled, and the dealer determined that the crankshaft and the thrust bearings had failed. The vehicle was repaired. The contact related the failure to NHTSA Action Number: EA25007 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure and partially covered the repair cost. The failure mileage was 60,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at 65 MPH, the DEF tank failed. The vehicle went into three phases of LIMP Mode and the vehicle unexpectedly decelerated while driving. The DEF system service message was displayed. The vehicle was taken to the local dealer, where it was diagnosed with DEF tank failure, and the tank needed to be replaced, even though the tank was full. The part was on backorder for several weeks. The contact was not provided with a loaner. The vehicle was repaired. The manufacturer was contacted and opened a case, but no additional assistance was provided. The failure mileage was approximately 70,000.

The frame of the back window is cracking allowing water to come in through the back glass. This is causing the headliner and other components such as air bags and other electrical components to get wet and damaged. This could cause risk of fire or failure of safety components within the vehicle such as air bags, cameras and other sensors. With water intrusion comes the high risk for mold to develop and cause serious health risks. GMC is aware of this issue and will not agree to repair it. A GMC dealer has inspected the glass and said it was a faulty seal but since it's not in the 3 year warranty window, it's not covered. Independent auto glass companies state they have seen this issue many times and the glass seal is faulty. GMC should do the right thing and fix this issue. This devalues the vehicle and the GMC brand and poses serious risks to driver. I have created a case with GMC and submitted photos, videos and dealership estimates for proof.

The frame of the back window is cracking allowing water to come in through the back glass. This is causing the headliner and other components such as air bags and other electrical components to get wet and damaged. This could cause risk of fire or failure of safety components within the vehicle such as air bags, cameras and other sensors. With water intrusion comes the high risk for mold to develop and cause serious health risks. GMC is aware of this issue and will not agree to repair it. A GMC dealer has inspected the glass and said it was a faulty seal but since it's not in the 3 year warranty window, it's not covered. Independent auto glass companies state they have seen this issue many times and the glass seal is faulty. GMC should do the right thing and fix this issue. This devalues the vehicle and the GMC brand and poses serious risks to driver. I have created a case with GMC and submitted photos, videos and dealership estimates for proof.

The frame of the back window is cracking allowing water to come in through the back glass. This is causing the headliner and other components such as air bags and other electrical components to get wet and damaged. This could cause risk of fire or failure of safety components within the vehicle such as air bags, cameras and other sensors. With water intrusion comes the high risk for mold to develop and cause serious health risks. GMC is aware of this issue and will not agree to repair it. A GMC dealer has inspected the glass and said it was a faulty seal but since it's not in the 3 year warranty window, it's not covered. Independent auto glass companies state they have seen this issue many times and the glass seal is faulty. GMC should do the right thing and fix this issue. This devalues the vehicle and the GMC brand and poses serious risks to driver. I have created a case with GMC and submitted photos, videos and dealership estimates for proof.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at 65 MPH, the DEF tank failed. The vehicle went into three phases of LIMP Mode and the vehicle unexpectedly decelerated while driving. The DEF system service message was displayed. The vehicle was taken to the local dealer, where it was diagnosed with DEF tank failure, and the tank needed to be replaced, even though the tank was full. The part was on backorder for several weeks. The contact was not provided with a loaner. The vehicle was repaired. The manufacturer was contacted and opened a case, but no additional assistance was provided. The failure mileage was approximately 70,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated that the vehicle made an abnormal sound while idling. There was no warning light illuminated. The vehicle was taken to the dealer, where the engine was disassembled, and the dealer determined that the crankshaft and the thrust bearings had failed. The vehicle was repaired. The contact related the failure to NHTSA Action Number: EA25007 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure and partially covered the repair cost. The failure mileage was 60,000.

To the best of my knowledge… My 2020 GMC Sierra Denali with a 6.2L engine and 74,000 miles had a complete engine replacement. One lifter on bank 2 was stuck, and the push rod in the cylinder was bent. The engine made a popping noise when starting. I took it to a GM dealership, where they quoted $9,200 to repair the issue or $9,600 for a brand-new engine with a 3-year/100,000-mile warranty. I know there is open recalls for 21’-24’ Models, but I would like some help with mine. This kind of problem shouldn’t happen on a GMC - loaded truck with only 74,000 miles. Thank you!

Truck broke down with a rear-wheel lockup and had the transmission replaced in June 2025. In December 2025 and February 2026, truck lost power two times and entered limp mode while on a major highway and major interstate. The problem was misdiagnosed in June 2025, diagnosed properly in December 2025, but not properly repaired, and diagnosed properly in February 2026. All three times the vehicle had this issue, two of the same exact DTCs were present. This is a safety defect, and I have lost all confidence that the vehicle is reliable enough and safe enough for myself and my family.

Truck broke down with a rear-wheel lockup and had the transmission replaced in June 2025. In December 2025 and February 2026, truck lost power two times and entered limp mode while on a major highway and major interstate. The problem was misdiagnosed in June 2025, diagnosed properly in December 2025, but not properly repaired, and diagnosed properly in February 2026. All three times the vehicle had this issue, two of the same exact DTCs were present. This is a safety defect, and I have lost all confidence that the vehicle is reliable enough and safe enough for myself and my family.

The 10L80 transmission had a catastrophic failure just outside of the GM warranty. At under 70K miles the pump gears came apart and sent metallic debris throughout the entire transmission and exhaust gaskets converter next to the transmission. These will need to be replaced. I have found multiple cases online with this 10L80 transmission where there has been significant problems with these transmissions blowing up or even causing momentary lockup with the wheels. This transmission is notorious for problems but has not yet been recalled. My mom and nephews were in the vehicle when it broke down putting their safety at risk on the the highway. This problem was confirmed by the GMC dealership here in Ruston, LA. The dealership has done the mechanical inspection. The engine started making an extremely loud noise and the warning lights did not even come on until I attempted to start it later after the breakdown.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while starting the vehicle, the engine hesitated while turning over. The vehicle started with the check engine warning light illuminated, and the DEF (Diesel Exhaust Fluid) sensor light was illuminated. The message “94 miles before vehicle enters LIMP Mode" was displayed and instructed the contact to see the Diesel Exhaust Fluid section of the Owner's Manual. The vehicle was restricted to a 65 MPH max speed. The vehicle was towed to a dealer, where it was diagnosed, and it was determined that the DEF tank pump assembly had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 121,000.

Odometer Fraud. The contact attempted to purchase a 2020 GMC Sierra 1500. The contact discovered a mileage discrepancy. The vehicle was a private sale. At the time of purchase, the mileage was 75,000. At the time of registration, the Carfax Report indicated that the mileage was 175,000.

Vehicle has 28,000 miles and auto shop states that the engine is blow, it's knocking and vibrating throughout the engine.

Engine failure at 84000

I was driving the truck on the freeway and the engine completely shut off with no warning. I pulled to the side of the shoulder and I could smell a burning smell. The truck wouldn’t start back up or move in neutral. Towed it to a shop and they said it had a camshaft issue and a slight knocking noise when they got it to fire up only would run for a little then shut back off. Now I’m having to replace the whole engine due to being bad with the cam code and knocking.

I was driving the truck on the freeway and the engine completely shut off with no warning. I pulled to the side of the shoulder and I could smell a burning smell. The truck wouldn’t start back up or move in neutral. Towed it to a shop and they said it had a camshaft issue and a slight knocking noise when they got it to fire up only would run for a little then shut back off. Now I’m having to replace the whole engine due to being bad with the cam code and knocking.

The backup camera is too bright at night and therefore useless . Tried searching the web but found no fix that would actually work. Took my truck to the dealer and they never heard of this issue even though there are numerous articles about it on the world wide Web.

February 28th 2026, I was driving on the highway with my children and suddenly without any prior warning my cars check engine light came on. It immediately starting losing power, made a knocking noise, and sounded like it was misfiring. Fortunately I was able to make it safely off the highway and have my car towed to the dealership. This was most definitely a life threatening situation which no one should have to face. The dealership dismantled my engine and i was advised the engine had an internal failure due to the valve lifter , rods , and camshaft damage. When looking online there are many complaints and lawsuits regarding this investigation of GMC’s 5.3 engine. I believe this was due to catastrophic damage of the components and there needs to be a recall regarding this issue. The car has always been properly serviced and regular oil changes.

While driving, my vehicle experienced a sudden and complete engine failure without any prior warning. There were no warning lights, dashboard alerts, or performance issues that would have indicated an impending mechanical problem. The failure occurred unexpectedly while I was actively driving on a public roadway. After the incident, the vehicle was inspected and diagnosed by a licensed mechanic. The diagnosis determined that an internal engine lifter failed, which subsequently caused damage to the camshaft. This type of failure appears to be the result of an internal mechanical defect rather than any form of neglect or improper maintenance. The abrupt nature of this engine failure created a serious safety hazard. The vehicle suddenly lost the ability to operate normally, forcing me to slow down and stop in active traffic. This unexpected loss of power placed my safety, as well as the safety of other motorists on the road, at significant risk. A critical engine component failing without warning while the vehicle is in operation raises serious concerns about reliability and safety. The vehicle has been properly maintained throughout ownership. All routine maintenance and servicing have been performed by licensed mechanics, and I can provide complete maintenance records documenting this history. At no point prior to this incident were there any signs, warnings, or diagnostic alerts indicating an issue with the engine. The vehicle has already been fully inspected and diagnosed by a licensed mechanic, and the findings are available for review. If necessary, arrangements can be made for the manufacturer or an authorized representative to inspect the vehicle and verify the damage. Given the sudden nature of this failure, the internal engine damage involved, and the safety risk it created while driving, I am requesting that this issue be formally reviewed and addressed by the manufacturer.

Hi, was driving Vehicle GMC 1500 Denali, vehicle Lost power, all Lites lite up on Dashboard, Vehicle Just lost power and i swerved off Road and sideswiped a Plant Holder on side of Road, damaging side passenger Rear door. I bought the truck to GMC Rvc and they said vehicle Blew Cam shaft and Lifters. I explained to them I'm very concerned for others safety in these Vehicles with the 6.2 Engine. Someone is going to get Killed or even a family. I did look up this vehicle its not listed in Recall, but this vehicle has same engine as ones in Recall. Rvc Gmc issued me a bill for repairs for the amount of $8185.20 and they stated they took 3k off invoice. I did Pay total Invoice....I'm just asking you to please look into this as this is defiantly an issue and this year should be listed on Recall as well.. Thanku for at least looking at this. My cell is [XXX] if you need to reach us...Thx.... INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My 2020 GMC Sierra Denali diesel with approximately 90,000 miles experienced two separate front suspension failures within a short period of time. The driver side tie rod and wheel hub failed first and required repair. Shortly after, the passenger side front suspension failed in a similar way and the vehicle had to be towed. These failures caused the front wheels to become unstable and created a serious safety concern while driving. Suspension components such as tie rods and hubs should not fail at this mileage under normal driving conditions.

Hi, was driving Vehicle GMC 1500 Denali, vehicle Lost power, all Lites lite up on Dashboard, Vehicle Just lost power and i swerved off Road and sideswiped a Plant Holder on side of Road, damaging side passenger Rear door. I bought the truck to GMC Rvc and they said vehicle Blew Cam shaft and Lifters. I explained to them I'm very concerned for others safety in these Vehicles with the 6.2 Engine. Someone is going to get Killed or even a family. I did look up this vehicle its not listed in Recall, but this vehicle has same engine as ones in Recall. Rvc Gmc issued me a bill for repairs for the amount of $8185.20 and they stated they took 3k off invoice. I did Pay total Invoice....I'm just asking you to please look into this as this is defiantly an issue and this year should be listed on Recall as well.. Thanku for at least looking at this. My cell is [XXX] if you need to reach us...Thx.... INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Hi, was driving Vehicle GMC 1500 Denali, vehicle Lost power, all Lites lite up on Dashboard, Vehicle Just lost power and i swerved off Road and sideswiped a Plant Holder on side of Road, damaging side passenger Rear door. I bought the truck to GMC Rvc and they said vehicle Blew Cam shaft and Lifters. I explained to them I'm very concerned for others safety in these Vehicles with the 6.2 Engine. Someone is going to get Killed or even a family. I did look up this vehicle its not listed in Recall, but this vehicle has same engine as ones in Recall. Rvc Gmc issued me a bill for repairs for the amount of $8185.20 and they stated they took 3k off invoice. I did Pay total Invoice....I'm just asking you to please look into this as this is defiantly an issue and this year should be listed on Recall as well.. Thanku for at least looking at this. My cell is [XXX] if you need to reach us...Thx.... INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving approximately 40 MPH, the check engine warning light illuminated. The vehicle was taken to a dealer, where it was diagnosed, and determined that the oil pump solenoid needed to be replaced. The vehicle was repaired, but after the repair was performed, the engine seized. The manufacturer was notified of the failure. The failure mileage was approximately 45,000.

At 96,000 miles (3,000 miles after the extended warranty expired), I noticed the "GM tick" more prominent and had more of a metallic sound than it ever did. Upon further investigation, it was found that a collapsed lifter may be the culprit. The truck was brought to the dealer and it was confirmed that the #1 hydraulic lifter had collapsed and needed replacement. This work was approved and tonight, I received a call from Rivard Buick GMC saying that the collapsed lifter also caused significant wear on the camshaft which also now requires replacement. Loss of power on the road poses a significant risk as I carry my children in the vehicle. No warning lamps, messages, or other indicators appeared before or when the issue occurred. The issue was reproduced by the manufacturer/dealer. The dealer Service Manager confirmed that this is extremely common with these trucks with the 6.2L engine and said it was a design flaw due to Dynamic Fuel Management, as well as the oil viscosity recommendation from GM being too low. The year group before and after the 2020 has been recalled along with TSB's issued, however, this group is not part of it. I contacted GM Customer Service (Case [XXX]) and was offered a 10% discount on the repair, being told that this is a "great deal considering the vehicle is out of warranty". GM Customer Service has now resorted to not answering any further questions after several attempts to reach someone. This is also after replacing the 10-speed transmission that was also not part of any recall but that was such an issue that the dealer was only able to source used transmissions rather than new parts. Clearly GM won't make the right decisions to back their products or customers, so NHTSA intervention is necessary. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The motor went to knocking and lost power. Cost us about 3500. To fix. Lifters went down cam went down which caused major motor knock and loss of payer

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at various speeds, the steering wheel became stiff and difficult to steer to the left or the right. The power steering and check engine warning lights were illuminated. The vehicle was towed to a local dealer, where it was diagnosed with a corroded body ground strap. The error codes were cleared, and a test drive was performed. The vehicle was repaired out of pocket. Upon further investigation, the contact related the failure to the GMC Customer Satisfaction Program: N252515590; however, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 37,061.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at various speeds, the steering wheel became stiff and difficult to steer to the left or the right. The power steering and check engine warning lights were illuminated. The vehicle was towed to a local dealer, where it was diagnosed with a corroded body ground strap. The error codes were cleared, and a test drive was performed. The vehicle was repaired out of pocket. Upon further investigation, the contact related the failure to the GMC Customer Satisfaction Program: N252515590; however, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 37,061.

Vehicle is shifting hard when switching gears. Typical with the recall and the valve body being the issue. Dealership is saying it is not covered by recall.

Misfiring due to DFM which is a common issue. Running a scan confirmed. I have installed a AFM/DFM disabler which seems to fix the issue.

Have not had my truck in over a month while it’s getting repaired had engine failure sure to faulty hydraulic lifters and camshaft failure due to the Dynamic fuel management system purchased warranty for my vehicle but this needs to be looked into it is unfair as a consumer that they are not doing anything about 2020 models and earlier they are just focusing on 2021 and up. They almost had me crash my truck due to power loss

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle unexpectedly sputtered. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with torque converter failure. The dealer determined that the torque converter needed to be replaced. The vehicle was repaired. The contact later stated that while driving at an undisclosed speed, the vehicle unexpectedly went into LIMP Mode. There was no warning light illuminated. On several occasions, the vehicle unexpectedly downshifted and lunged forward while stopped at a traffic light. There was no warning light illuminated during the failure. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 97,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, there was a loud rattling sound coming from the engine. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with crankshaft failure. The contact was informed that the crankshaft could be replaced; however, the dealer suggested that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 44,000.

On Friday, January 30, 2026 while driving our 2020 GMC Sierra 1500, we experienced sudden loss of power and the motor making a faint rattling noise. The motor soon after began making a horrible sound - - it was obvious something was very wrong. This vehicle only had 31,995 miles on it at the of the issue. We had the truck towed to the dealer the following day for evaluation. Upon inspection, it was determined that the #5 lifter had collapsed and the left bank of lifters needed to be replaced at an estimated cost of $4500. There were no warning lamps or alerts on our app for over 24 hours. Once at the dealer, we explained to the service advisor that our research concluded that GM is fully aware of these issues and that they are under investigation for possible recall. Our service advisor then made a call to GM who agreed to cover this repair under warranty (which we appreciate and feel was the right thing to do). However, after additional research, we are concerned that the right bank of lifters will fail next, or even worse, catastrophic engine failure that GM will refuse to cover. It is our understanding that NTSB is aware of these issues and is in the process of conducting an investigation. I would like to have our issue added to the investigation.

The brakes suddenly activate and cause the vehicle to rapidly stop with no warning of any kind and without any braking action being taken by the driver. Then, the brakes do not release and the vehicle cannot be moved as the brakes remain on. Turning the engine off and then restarting it or shifting to other gears does not release the brakes. The vehicle remains immobile and cannot be driven. After a few hours have passed, like overnight, the brakes release and the vehicle can started and driven just as if nothing had happened. A message briefly appears on the vehicle information screen each time this inadvertent braking occurs. It reads, “Brake Failure System”. These brake lockdowns occurred when driving on streets and in the driveway. No accident resulted but could have easily occurred. This is dangerous for a driver and occupants of a vehicle with this safety flaw as well as for other people and vehicles in the vicinity. This has happened five times. The last two instances resulted in the vehicle being loaded onto a tow truck and taken to a dealer of the vehicle’s manufacture. Thus far the dealership has not found what may be causing this intermittent braking problem.

The brakes suddenly activate and cause the vehicle to rapidly stop with no warning of any kind and without any braking action being taken by the driver. Then, the brakes do not release and the vehicle cannot be moved as the brakes remain on. Turning the engine off and then restarting it or shifting to other gears does not release the brakes. The vehicle remains immobile and cannot be driven. After a few hours have passed, like overnight, the brakes release and the vehicle can started and driven just as if nothing had happened. A message briefly appears on the vehicle information screen each time this inadvertent braking occurs. It reads, “Brake Failure System”. These brake lockdowns occurred when driving on streets and in the driveway. No accident resulted but could have easily occurred. This is dangerous for a driver and occupants of a vehicle with this safety flaw as well as for other people and vehicles in the vicinity. This has happened five times. The last two instances resulted in the vehicle being loaded onto a tow truck and taken to a dealer of the vehicle’s manufacture. Thus far the dealership has not found what may be causing this intermittent braking problem.

I had a complete engine failure that I had to pay out-of-pocket for I really think that this vehicle should’ve been included in the 2021 and beyond engine recall for 6.2 GMC Sierra‘s. I drove to work one morning Fein after work I turned my vehicle on, and the engine started shaking violently and smoke coming out of my exhaust like I’ve never seen it before dealer said engine was completely blown and had to be repaired again I paid for this out of my own pocket. It is now coming to my attention that this vehicle is being looked at as an engineering analysis in line with the recall for the 2021 in above GMC Sierra‘s what do I need to do?

My engine is projecting a ticking sound. Oil consumption is extreme.

My engine is projecting a ticking sound. Oil consumption is extreme.

Engine failure as related to RQ26-001. engine misfires after following recommended maintenance schedule for 6.2L engine. Vehicle is at dealership and available for inspection and dealer is recommending engine replacement. Engine light came on and was brought to GMC dealership same day.

Catastrophic engine failure at 62,445 miles. Dealer state excessive oil in cylinder 7, ring failure. Recommendations; remove and replace engine.

I am writing to formally express my dissatisfaction regarding a significant safety and reliability issue with my 2020 GMC Denali. Specifically, the vehicle is experiencing premature wear and imminent failure of the front ball joints. I expect the suspension components of a premium Denali-trim vehicle to last significantly longer than the 37,061 miles currently on my odometer. Industry standards typically place the lifespan of these components between 70,000 and 150,000 miles. Technical Details of the Failure: The vehicle is currently exhibiting the following symptoms of accelerated ball joint degradation: •Excessive Vertical and Lateral Play: Inspection reveals play in the right lower ball joint that exceeds the manufacturer’s maximum allowable wear specifications. The left lower Ball Joint is starting to have a small amount of play, according to the technician

My 2020 GMC Sierra 1500 experienced a premature transmission failure consistent with GM’s known 8-speed transmission defect. My safety and the safety of others were put at risk if/when the transmission occurs a temporary lockup which can/will cause the vehicle to stall on the highway, and potentially create a minor/major automobile incident if vehicle stalls. The vehicle was taken to dealership Capital Chevrolet Montgomery, AL where dealership technician diagnosed/confirmed the issue along with pictures of internal transmission failed components as well as recommended resolution for fix. The vehicle has been inspected by my out-of-pocket expense extended warranty company Endurance Warranty Services sub-contracted repair claims adjuster. No warning lamps, vehicle messages, or other symptoms of the problem prior to the failure were noticeable; the vehicle had multiple diagnostic scans prior to original sale and after sale to present no issues or trouble scans. the first issue appeared or was noticeable 12/08/2025. GM has refused action by asserting warranty expiration despite widespread knowledge of this defect. The vehicle has been out of service since December 8, 2025.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine made an abnormal popping and crackling sound. The traction control, check engine, and several other unknown warning lights were illuminated. The message "Service Emergency Brake" was displayed. The engine later made knocking sounds, and the vehicle vibrated while driving. The vehicle was towed to an independent mechanic, who determined that the engine needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the year and VIN were not included in the recall. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 138,000.

I purchased my 2020 gmc sierra 1500 6.2L in September 2024 with 80,000 miles. 9 months later the lifters gave out. Had them replaced and 6 months later, the lifters again were bad and was knocking. They are now replacing the lifters and cam. I am so disappointed that this is happening. I hear that the 2019 and 2020 was not included in this recall! Why not!! If it’s still doing the same thing and it is the same engine, why isn’t my truck in this recall? I would like to know why? If it is doing the same thing as the recall, shouldn’t it be covered by this recall? Best, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and hauling a boat, the vehicle shook violently and made a loud banging sound. The vehicle failed to accelerate above 40 MPH. The check engine warning light was illuminated. The vehicle was towed to the dealer, and it was determined that there was a misfire in cylinder #6, and that the engine required further inspection. The vehicle was not repaired. The contact related the failure to NHTSA Action Number: EA25007 (Engine, Engine and Engine Cooling). The manufacturer was not made aware of the failure. The failure mileage was approximately 87,000.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and hauling a boat, the vehicle shook violently and made a loud banging sound. The vehicle failed to accelerate above 40 MPH. The check engine warning light was illuminated. The vehicle was towed to the dealer, and it was determined that there was a misfire in cylinder #6, and that the engine required further inspection. The vehicle was not repaired. The contact related the failure to NHTSA Action Number: EA25007 (Engine, Engine and Engine Cooling). The manufacturer was not made aware of the failure. The failure mileage was approximately 87,000.