general problems of the 2020 GMC Sierra 1500 - part 1

My 2020 GMC Sierra 1500 denali with l87 6. 2l v8 suffered a catastrophic, silent seizure at 108,000 miles. Driving at highway speeds, warning light stating shift to neutral and press start, engine completely shut off and would not turn back on. I was in the car with my 3 children about to make a turn across a 4 lane highway. I was able to recognize that there was power loss quickly enough that we were safely within the turn median, and fortunately a "good samaritan" stopped to assist us in getting across the highway into a parking lot. I hate to think what would have happened had this power loss occurred during the turn. There was no warning light, sound or other issue prior to this occurring. The vehicle has been meticulously maintained with all services occurring at my local GMC dealership. We had the truck towed to the dealership who confirmed the engine needs to be replaced.

While driving at night, a low oil pressure warning light illuminated on the dashboard. The following morning, I checked the oil level using the dipstick, which indicated a normal reading. Based on this, I proceeded to drive the vehicle. Shortly after departing, the engine began knocking severely. I immediately stopped and returned home. The vehicle was towed to a GMC dealership for diagnosis. The dealership determined that the engine had experienced catastrophic failure and required complete replacement. I was quoted $11,000 for the repair.

The engine had a critical failure at 49,000 miles. It was replaced under the drivetrain warranty. That came with a 12 month, 12,000 mile warranty. Now I have a second engine failure at 59,000 miles. This will come with only a 12 month 12,000 mile warranty because it is not under recall. Also my transmission is now slipping and they are replacing the valve body. They had my truck for 4 months the first time and one month this time. These are the exact same issues with 2021 - 2025 GMC 6. 2l and 10 speed transmissions. If I the issue had happened 6 months later I would have no warranty. I want a recall on 2020's please.

I again have noticed intermittent pulsing at low to medium speeds. At roughly 1k-2k rpm the engine at or about 10-20 mph is pulsating or hesitating with an obvious pulse which you can see on the tachometer as well (bouncing. ) it seems like there is either a computer, fuel flow or electric issue. Also, at speeds up to the 40 mph range, this is happening as well. Yesterday while towing a small 7'x12' empty dual axle trailer I noticed it again, I occasionally use my trailer to haul small loads up to 4500lbs. This has happened before but this time I decided to notate this on your site, since reading about ongoing problems with the 2020 6. 2l GMC Sierra 1500. I was aware of the other following years, 2021-2024? issues and that is why I purchased this 2020 year model. My truck will be available for inspection when the request is sent to me. Safety was not an issue, I ran my truck most of the day. I have not yet notified my Chevrolet dealer, roger dean, cape coral, FL. My truck has not yet been inspected for this issue. There were not any lights or warnings on display at time of incidents. Thank you, [xxx] [xxx] [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Good evening, I want to formally document what happened today regarding my GMC sierra after I brought it to the dealership on Friday morning for transmission concerns that I had already reported. At that visit, the vehicle was inspected, and I was informed that the truck was still safe to drive while waiting for the extended warranty approval for the replacement parts that were needed. Unfortunately, today my family and I experienced a very serious and frightening incident on the expressway. While driving, the truck suddenly lost power, barely moved forward, and began shaking violently. We were placed in a very dangerous situation in traffic and struggled with great difficulty and fear just to make it home safely. Once we arrived home, the vehicle completely shut off and would not restart again. This situation was extremely alarming, especially because I had already reported the transmission problems and trusted the guidance given to me that the vehicle was still drivable. My family’s safety was put at risk, and I need this matter to be treated with urgency and seriousness. Please advise immediately on the next steps regarding the vehicle, towing assistance if necessary, and how this situation will be properly addressed. Thank you.

2020 GMC Sierra 1500 began experiencing a slight knocking sound - mechanic diagnosed as a crankshaft issue. As of last night, 5/10, the truck's knocking sound got extremely loud, the exhaust pipe emitted smoke, and the truck began "bucking. " no warning messages or lamps appeared.

• while driving a loud popping and clicking noise started coming from the engine and the truck started shaking. The vehicle is available for inspection • it was a busy two lane road and I had to continue about 30mph under the speed limit to safely get off the roadway • upon start up the engine clicks and pops with rough idle and the truck shakes. A mechanic looked at it and stated it sounds like a lower rod bearing noise • no further inspections have been done • a service esc warning popped up when the engine started making noise during the incident. The truck had been taken in twice for rough idle and engine noises prior to 100k miles, but the dealership stated that the noise and feel was normal for the 6. 2l engines.

6. 2l v8 engine. 2020 build, GMC Sierra 1500 series. Same engine in the existing recall for 2021-2024 models. Received a call from the service department of the dealership that after changing the oil and restarting the truck to reset the oil change indicator the engine shut down. Assistant service manager, stephen poulson [xxx] ) called and provided information that the engine seized and that the technician cannot manually forward or reverse the engine with a breaker bar. According to the technician, this is indicative of a catastrophic failure consistent with the existing recall. The vehicle is currently at carr vancouver Buick GMC and is available for inspection. Nhtsa has permission of this owner to inspect this vehicle involved if they choose. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Sitting at a red light and when the light turned green, the engine made a noise and lost power while trying to cross the intersection. The check engine light came on along with some other lights. It was then towed to a mechanic and the engine had to be replaced due to failure of the lifters. The mechanic said it is a common issue with the gm 5. 3 engine but unfortunately their has not been a recall.

Complete engine failure with 62,500 miles. Truck appears to have the same problem as the 21-2024 which is currently recalled and engines are being exchanged.

I’m scared to drive my vehicle because of the 6. 2l v8 ongoing engine failures! I believe it to be unsafe for travel never knowing when the engine will fail. Now with over 1 million failures of this engine!.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed 60 miles away from home, the vehicle lost automotive power and stalled. The contact stated that the vehicle started smoking. Several unknown warning lights were illuminated. The vehicle was taken to a local dealer, where it was diagnosed and it was determined that the failure was due to an internal failure with the camshaft and the engine. The vehicle was not repaired. The manufacturer was contacted and referred the contact to the local dealer for assistance. The failure mileage was approximately 167,570.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle decelerated to 30 mph. The check engine warning light was illuminated. The vehicle was taken to a local dealer, where it was diagnosed, and determined that the timing belt needed to be replaced. The part was on back order. The vehicle was not repaired. The contact stated the vehicle previously experienced brake failure, sensor failure, and glow plug failure. The manufacturer was contacted, but no assistance was provided. The bbb referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 80,000.

We heard a knocking noise and took the truck to the nearest gm dealership. The engine had to be taken apart. The engine is a l87 6. 2 liter v8. The gm dealership service department diagnosed camshaft damage that caused lifter failure. We have since been informed that gm has known about the failure of this engine for many years. In our case, we were fortunate that the engine did not fail when we were on the expressway. This is a huge safety issue. There were no warning lamps or messages from the vehicle, but we heard the knocking noise. We are facing a minimum of a 10,000 dollar repair and will not feel confident that this engine will not put our safety at risk in the future. We understand that the NHTSA has initiated an engineering analysis regarding this engine for the model years 2019 to 2021. (ea25007). We wanted you to have the information of another dangerous engine failure.

My 2020 GMC sierra 6. 2l (only 46,000 miles which is under warranty mileage criteria), suffered catastrophic engine failure while at 40 miles per hour out of no where and rolled without power for about ~60ft. Power came back on, and I was able to get closer to the dealership but again, lost all power and rolled for about 60ft again right in front of the dealership. The truck died while attempting to make a left turn (in oncoming traffic), it got going again in time to finish the turn. When I pulled into the dealership it pulled code p0016 which is the same code for the 2021-2024 recall currently for the 6. 2l gm engine. I had all oil changes completed on time and can show evidence of them. Other repairs, recalls etc were completed at the GMC dealership. The 2020 sierra 6. 2l should absolutely be included on the gm recall. Same issues as 2021-2024. Funny how 2020's just reached over on time limit for warranty. The repair estimate for my truck is over $13k!!!.

When the truck was idling the dod/afm turned on and disabled a cylinder and now I’m just having codes pop up for cylinder misfires.

After owning this truck a little over a year I’ve had to replace the transmission and now it’s in the because the motor sounds like a bag of marbles was put in it and the warranty company is a joke they only want to replace just the cam and lifters but yet the dealership hasn’t be authorized to go to the bottom of the motor to check it out this truck has been nothing but a lemon!!!!!.

My engine suffered an internal catastrophic event, and needs to be replaced.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle went into limp mode, and several unknown warning lights were illuminated. The vehicle lost automotive power. The vehicle was taken to the dealer to be diagnosed. There was a knock coming from the engine, there was fuel injector failure, a heated oxygen sensor control module bank 1 failure, and fuel system failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 134,648.

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!.

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

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.

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.

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 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 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.

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).

While driving on the highway, my engine failed unexpectedly and I had to coast across the highway without power. I had the vehicle towed to a gm dealership, where I was informed the failure was due to a lower-end engine issue and that a full engine replacement was necessary. I am aware of known issues with gm’s 6. 2l engines and asked the dealership about the related recall. They acknowledged that the failure I experienced is consistent with the symptoms seen in the defective 6. 2l engines. However, they stated that because my truck is a 2020 model, it does not fall within the affected VIN range. I ultimately paid nearly $11,000 for a new engine. Given the nature of the failure and its alignment with known issues, it is difficult to believe this was merely coincidental. I strongly believe the same defect exists in my engine, despite it not being included in the current recall range.

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.

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 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.

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.

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.