general problems of the 2020 GMC Sierra 1500 - part 2

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.

The bearings in my engine failed while on the road! the dealer says I need a full engine replacement for $16,000. There were no warnings or indication there was a problem. The vehicle has been maintained perfectly since it’s purchase.

Sudden engine issue. Knocking, power loss, brake and steering warnings. Severely damaged engine. Mechanic says 2 cylinders are irreparably damaged and entire engine must be replaced.

My 2020 GMC sierra has had poor gas mileage problems I have taken it to gm a few times with them not able to dind anything wrong through diagnostic. A couple years later my horrible gas mileage came back and service ecs and stabilitrack message came back on and disappeared. I spoke to another shop and they advised me its the dfm lifter issues that everyone has been talking about. So the shop performed the well know fix and has fix the issue. A month after now the valve body gave me a p2817 code showing that the solenoid is stuck in the off and was also advised that this is a know issue being addressed. Currently the truck is in the shop. When is enough enough with all the issues across the nation whwn is gm going to make it right.

Driving to the lake on the highway towing a trailer, a loud tapping noise started followed by vibration. Engine seems to have lost power during acceleration.

There is a click/ticking noise when vehicle is started. Noise gets louder and faster when accelerating. Have taken vehicle to 2 mechanic shops and been told by both places it is bad lifters and exhaust manifolds. I took this truck in because of loss of power. This issue has put me in unsafe/ dangerous positions on multiple occasions.

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.

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

Bought the truck less than four months ago and as of yesterday it consumed a substantial quantity of oil and later refill. However today it made a noticeable noise until it shut off permanently. Dealer did not disclose this.

We were driving down the interstate at about 75 mph when a message came up that said to shift to neutral and push the start button. My husband did and it continued to drive perfectly fine, but about 6 miles down the road it did the same thing again except when he pushed the start button it did not start. I cannot begin to tell you the cause as to why it would’ve been doing that as I have never had any other issues with it.

I started to notice changes in performance around 75k miles. Seemed like performance was subpar compared to what was the norm. Seemed to lose some power. Minimal at first, more so just recently around 90k. Oil consumption was starting to accelerate at each oil change at 75k, 80k, 85k, 90k. To the point around 85k and 90k that I would not go over even 1 mile from the 5k threshold without changing the oil. Around 90k I could tell it was not getting any better, deficiencies were accelerating it seemed. At 91k miles I started to hear clicking noises and loss of power, starts were getting rough, bouncing at idle. I stopped driving it, only driving it to the dealership where I brought for a look at it. Will be driving it again for them to do a deeper diagnostic. Many misfires at cylinder 5. Po305 the issue. Showed up around 91k miles on 12/17/25 now investigation into my model. I see online.

I took my 2020 GMC sierra in for an oil change. The engine seized when it the technician tried to restart the car. We had it towed to GMC where they confirmed the engine seized. The oil repair shop then replaced the engine and when doing so confirmed the original threw a rod which is the same recall issue that is occurring with the 2021-2024 models. I have since taken the car to GMC for a full inspection and made additional repairs. The vehicle is available for future repairs. My safety and others are at risk as the engine could seize leaving my family stranded or endangering others on the road if the seizure occurs while driving. Yes the vehicle was inspected at the GMC dealership and the shop where the engine was replaced with another l87 engine. There was no warning the engine seized after an oil change.

Engine fan has been constantly running, with engine temp reading around 230 consistently. After driving 5 miles on the interstate it shot up to 260 and said “engine temp overheating, idle engine”.

My 2020 GMC Sierra 1500 denali with the 6. 2l l87 v8 just began experiencing a new rough idle with intermittent rpm dips. There are no engine codes or warning lights. Idle drops are noticeable, suddenly began this week. I am concerned due to ongoing NHTSA engineering analysis ea25-007 involving this engine. Some owners reported engine failure with little warning. The truck has right over 68,000 miles on it and has had every oil changed performed at a gm dealer. I have had to top off the oil between cycles and always used the recommended oil, being the dexos gen 3 due to the truck burning a small amount of oil. More detail on a possible cause. I believe it would be worth investigating the dfm technology. I will be performing a fuel cleaner and possibly a lifter cleaner and/or additive. I would like to tune the truck and turn off the dfm since this is what I have read causes the truck to burn oil and damage the lifters. However, I will wait until this analysis is completed before deciding to change the truck's stock tunes.

This is the 3rd catastrophic engine failure since purchasing this new vehicle from the dealership, the vehicle is currently at the dealership and is available for inspection. The latest diagnostic report has been attached from the dealership for reference. My safety and the safety of others was at risk with each occurrence. The 1st occurred on the interstate when a lifter rod bent causing loss of power with no warning, engine was rebuilt by the dealership. The 2nd occurred on the interstate when a different lifter rod bent causing loss of power with no warning, engine was rebuilt again by the dealership. The 3rd occurred just recently while on a highway. The engine suddenly turned off with no warning. The dash told me to put it into neutral and start again. I had to coast the truck for a long distance after the sudden loss of power in order to attempt to restart the engine. The engine would not start. The diagnostic report from the dealership states "engine is seized tight, maxi fuse is blown, needs engine replacement. ".

My 2020 GMC sierra with a 5. 3l engine and 78,272 miles on the vehicle, experienced damaged lifters which also resulted in a damaged cam shaft. The total repair bill was $9,208. 86. While in the GMC dealership for repair, there were 2 other trucks - same model, same year, same engine - in for the same repair. When searching on-line, I found the recall for the GMC 6. 2l engine for similar issues. It is my opinion that the 5. 3l engine is experiencing the same types of issues. I have driven GMC trucks for almost 40 years and have never experienced these types of issues. I have been told by several people that it is related to the dynamic fuel management system and to fix the problem to disable the system to keep the truck in v8 mode. There are several solutions on line to make this happen. I am no engineer and only provide this as background information. From my perspective, it is clear that gm has a problem (whatever the root cause) with their 5. 3l engines.

I purchased my 2020 GMC Sierra 1500 at4 with the l87 6. 2l v8 new from a GMC dealer in March 2020 for $65,910 (VIN [xxx]). The truck has primarily highway mileage, very little towing, and has been well maintained. At 166,634 miles on [xxx], the truck developed a flashing check-engine light. The GMC dealer diagnosed “cyl 3 lifter failure with camshaft damage” and determined that replacing the engine was preferable to repairing it because of the vehicle's mileage. The dealer installed a replacement oem GMC engine and replaced both broken engine mounts. The replacement engine and installation cost $11,778. The replacement engine has subsequently required multiple repairs. At approximately 170,411 miles, the GMC dealer documented an exhaust leak that had occurred since the engine repair and a coolant leak from the upper radiator hose; both were repaired. At approximately 187,699 miles, the truck experienced overheating, coolant leakage, and loud engine-area noise. The dealer found that the water pump was coming apart and replaced the water pump and related components. I am reporting this vehicle because it is a 2020 sierra equipped with the l87 6. 2l engine and experienced catastrophic lifter/camshaft failure requiring complete engine replacement, followed by multiple engine-related repairs. I believe this history is relevant to NHTSA's investigation of l87 engine failures in earlier model years and warrants consideration when evaluating whether the known l87 engine defect extends beyond the vehicles currently covered by the recall. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).