2021 GMC SIERRA 1500 Engine Problems

Driver side lifters collapsed and push rods failed on freeway without warning at 12900 miles on truck.

On the morning of 1/19/25, my 2021 GMC Sierra 6.2L AT4 went into limp mode heading south on HWY 207 in Leavenworth, WA at approximately 60 m.p.h. Fortunately, I was able to avoid a rear end collision. I quickly turned the truck off in the middle of the road and restarted it with a CEL. When I returned home almost 180 miles away, my local mechanic diagnosed a code P0303 and cleared it. Since, the truck has continued to shutter at various speeds without throwing a code. It is currently at Haselwood GMC in Bremerton, WA being scanned, recorded, and findings set to GM waiting for resolve. I have notes, exact dates, times, call records, return voice mail messages, and dealership personnel spoken to, etc. The dealer’s lead technician and I were able to replicate the shutter on a road test together on 1/27/25 at 3 p.m. after having driven...

lifters in the left and right side snapped into 3 pieces. Caused engine failure happened 2 different times. All before 50,000 miles. The first time was before 30,000 miles.

Engine failure

We have had several times where we are on highway and our truck like slams on the brakes causing us to lose control. It was a recall on it and GMC fixed it and within the same week of them fixing it it happened 3 times back to back. Making my truck to force another car to steer out of my way and actually went off the highway. Thank god it was just dirt snd he didn’t get hurt or anything. But I am scared to even drive my vehicle! It starting Happening for about a year now. And it would only do it like every couple months but now it’s has done it 6 times in the last 2 months!

Engine knocking and metal in oil. Been to the dealership and even though it's under warranty they will not act on it due to no check engine light present. It's making it difficult to trust driving the vehicle anymore because of the thought of the engine shutting down without warning anytime. This complaint is documented and confirmed by a dealership. They made me pay the check out fee and recommended i keep driving the vehicle until the motor locks up.

I was notified at the dealership that my truck had metal in the oil that is causing the oil sensor pump to send a ln engine code. The fix is a new engine.

Lifter noises, error codes for misfires, lost power

Le Moteur Le 13 décembre 2024 le véhicule arrêté subitement je tente de le redémarrer et ne demarre plus à plusieurs reprises je branche un obd2 et cela indique crank sensor j'envoie le véhicule au dealer et me dise qu'il y a quelque chose dans la base et aujourd'hui ils y est encore Les pneus Certains Flan de pneu de ce véhicule sont fissures tous le tour des roues

Multiple injector and lifter failures. Occurred on 2 separate occasions. Taken to dealer the first time. Told injector failure and lifter failure. Less than a week later experienced multiple lifter failures. Taken to dealer again for repair. They only replaced some of the affected lifters, even though TSB from GM recommends replacement of all of them. Currently awaiting failure of additional components not replaced. There was no warning of either occurrence. Was only driving 45 mph on my way home the first time. The second occasion was on initial start up at Dr office. Opened a claim with GM on my own, as dealership was negligent or unwilling to contact GMC about these failures, even though I provided them with the appropriate TSB directly from GM.

We had to replace the transmission at 70,000 miles even though problems were reported to the dealer at 53,340. This repair costed $2300 on a 1 year old truck. Then we needed to replace a solenoid circuit which was not covered under warranty. We repaired this 2x (the second time covered). Then at 147,000 miles 9/24, there was a cylinder misfire which bent the push rod and collapsed lifter. This engine repair cost $8300.00 dollars. Who has to replace an engine on a truck that's 3 years old. This is a defect. Please help us. We have spent over $10,000 on repairs. We faithfully do our changes and service.

I got off work started my truck heard a few pops. As I was driving the vehicle started jerking like the brakes were being applied. Then I noticed a yellow engine light and a ESC light come on. I pulled over to check vehicle and all the lights went off. Dealer was just a few miles away. So I started back up and drove to dealer. On the way to dealer vehicle started a tapping noise. Then a new message flashed something about my steering will be affected. I got I to dealer safely. Where I left the truck for repairs.

at 8500 miles the engine had lifter go out while I was driving down the highway cause to truck to vibrate and becoming on unsteady causing me to pull over in the middle of traffic. later at 36500 miles it had another lifter go out this time I was driving home at a slower speed but still cause me to have to pull over vert fast as the vehicle became unsteady and vibrated causing all the alarm to come on. Both times the truck was fixed under warranty nut they replaced it with the same parts that are causing the problems. Soon my truck will be off warranty and this will come out of my pocket.

I purchased this vehicle new in 2021. It is an Ultimate Denali trim level with a 6.2 engine. Within the first year, the driver's side head on the engine had a massive failure with only 7,000 miles. I started up the vehicle and was parked idling briefly when several light came on along with a rough idle and some exhaust smoke. I contacted On Star, who could not diagnose the problem. The vehicle was disabled and ended up being towed to the dealer, where it was being repaired for 10 days. The lifters, valves and push rods were replace. The mechanic admitted there was an internal GM problem with the 6.2 engine. I asked for the same repair be made on the passenger side head. The GM dealer refused, knowing of the faulty factory installed parts. The polished tailpipe tips were not replace and were stained by the black exhaust....

Engine failed due to a loss of oil pressure. Rod bearing failed which cause metal to be dispersed throughout the engine causing the engine to seize from a sudden loss of oil pressure from oil pump failure. Engine was replaced in June 2024 failure happened in May 2024. While driving a system message came on DIC that stated pull over immediately to prevent engine damage and no oil pressure. I was driving uphill with cars on my right in the #2 lane. Engine shut off before I could pull over resulting in decreased braking power and a lack of steering. I almost hit 2 vehicles trying to pull over to get my family to safety on the right hand shoulder. I couldn’t pull over to the left hand shoulder as there was a guardrail in the way. When I got my vehicle pulled over the only thing that stopped my...

L87 engine problems. I have had failed lifters, on top of transmission issues and a current oil consumption issue where I have to add two quarts of oil (sometimes more) without any indication of low oil. I took my vehicle into the local dealership and the technician asked if I had gotten any low oil indicator and I stated no. He proceeded to tell me it had little to no oil in it. Imagine this at highway speeds and sudden engine seizure.

I received a notice of a recall for a known problem with GMC transmissions. it is very well known that these transmissions lock up and cause problems with braking and can cause the vehicle to slide off the road when the tires lock up. it also causes hard shifting, which I have experienced. GMC said they will not fix the transmission, they instead will add a device to monitor the transmission, so when the transmission locks up and causes an accident, it will let me know that it was the transmissions fault!!! How is this legal? they will let me know that their transmission caused the accident after the fact? why not fix it? typical of government to do nothing about safety... and instead make laws that allow big corporations and government to make money off of peoples deaths!

The engine blew up at 67,000 mile while driving down the road. Not sure what happened but there was no warning signs at all. The dealership said they couldn’t know for sure what happened but most likely the oil pump went bad. I have spoken with a few people that have had this same problem with the 6.2 liter engine. It needs to be looked into because this could have caused a major accident on the highway.

On memorial day weekend 2023 my truck ,2021 GMC Sierra AT4 was making a awful noise. I pulled over and vehicle died. had it towed and the warranty covered new engine replacement at 54678 miles(large deposit of metal in the oil pan). June of 2024 again, traveling out of town and pickup making terrible noise and shaking at 76651 miles. Replaced lifters in vehicle. October 11, 2024 took vehicle in for oil change, drove 25 miles and vehicle making terrible noise. Pulled over and pickup died. Had it towed to dealer and they are saying it needs a new engine. ( 87000 miles) they are saying its out of warranty. There seems to be a serious problem with this engine( 6.2) in all the research I am finding. I now have a pickup that I am still making payments on , that I cannot drive.

The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 45 MPH, there was an abnormal ticking sound coming from the vehicle. The contact stated that several unknown warning lights were illuminated. The vehicle was placed on a trailer and was taken to an independent mechanic who stated that the lifter and cam shaft needed to be replaced. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 133,000.

Per the dealership: Lifter failure, crankshaft failure, metal shavings in the oil. Complete engine failure.

The contact's husband owns a 2021 GMC Sierra 1500. The contact stated that while her husband was driving 80 MPH, the vehicle stalled. Additionally, the "Shift to Neutral and Restart" message blinked. The vehicle was steered to the side of the road where the vehicle failed to restart. The vehicle was towed to an independent mechanic where the failure was not able to be replicated. The vehicle was then towed to the dealer where it was suspected that the crankshaft bearing had seized, putting pressure on the starter, causing a short. The contact was informed that the engine needed to be taken apart for a proper diagnostic test. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 81,000.

The engine locked up on the truck due to bad lifters. It has the 6.2L engine and after talking to several mechanic shops and research online this is a very common issue. GM is having to put lots of new engine in under warranty due to this issue. They need to have a recall to fix a known issue that is costing people thousands of dollars to replace the whole engine in the truck. We was driving down the hey today and with no working at all the truck died and and would not crank back over. We had the truck towed to a repair shop to find out that our truck had the same issue that lots of people are having and now it’s gonna cost us several thousand dollars to have fixed when realistically GM should be paying to fix this problem.

On the evening of 5/6/24, my husband was driving home in our 2021 GMC Sierra 1500 when the truck started to run hard, shaking, and the check engine light came on and was blinking. He pulled onto the side of the road immediately and more messages were coming across the dashboard. The truck was towed to a dealership that same night. Once the dealership assessed what was wrong, we were advised by the dealership who confirmed the lifters failed. The truck is currently still sitting at the dealership as we're waiting for the parts because we've been told multiple times that the parts are on backorder. I understand the truck is available for inspection as its been sitting on the lot since 5/6/24. This is the first time this has happened to the truck, zero prior issues. The truck has great service records and has always been properly maintained. We...

On [XXX] at approximately 3 pm I left my house and was traveling on [XXX] in Fort Mohave Arizona I was only traveling 7 miles. When I looked at the temperature in the cab was 121 degrees a few moments after the display system went black and never turned back on. I arrived at the store 4 minutes after the display shut off with no warning lights or any type of notification on my phone, I had rolled down the windows to get air in the cab to see if that would help cool down if needed. I was in the store 20 minutes. I returned to the truck turned it on and everything was normal, from there I drove back home nothing happened on my drive back the display was working. At 8 30pm I was traveling on [XXX] Driving towards a casino called Avi. I had the driver's...

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate as needed and made an abnormal sound. The contact assumed that the sound was coming from the transmission and the vehicle was taken to a dealer. The dealer diagnosed the vehicle and suggested that the failure might be a pulley or a rod bearing failure. The contact took the vehicle to another dealer who confirmed a rod bearing failure. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was approximately 46,000.

The coolant control valve is faulty and needs to be replaced. GMC and the dealership know about the issue (Bulletin No. PIP5791), but are not fixing it in a timely manner. This is a safety concern as the system will automatically reduce engine power, which is a major concern when towing and/or in mountainous terrain.

The component that has failed is the engine coolant flow control valve AC Delco part number 55516369. Unfortunately the part is still installed on the vehicle. It has been taken to a dealer and this is a known issue but no recall has been issued. The check engine comes on sometimes but not always, sometimes the pickup has plenty of power to drive and sometime it will barely pull itself, all in the same trip without shutting the ignition off. The symptoms first started in December of 2023, but were sporadic, now it is nearly everytime the pickup is started. It is extremely dangerous to drive this vehicle when it has a problem. You cannot tell if it will accelerate normally or is you will push the pedal and it does nothing. The part to repair the problem is on backorder and no release date is yet available. We have...

I purchased this vehicle used with approx 16k miles on it. Not long after getting it - as I was driving it started dinging and then would shut off. Sometimes I’m in the fast lane going 75Mph and it’ll just shut off. The dealership can’t get it to repeat itself. They said they’ve heard of it happening before but it throws different codes. There’s no rhyme or reason to causing it to shut off, but here lately I don’t even get the warning bell. It just dies on me. As soon as i shift it to neutral and press start it’ll restart instantly. But it’s scary nonetheless, and causes me to drop speed instantly and poses a safety risk especially when I have semi’s or other vehicles close behind.

"Service parking brake" "steering assist is reduced drive with care" comments showed up on screen…check engine light on, truck shaking/ vibrating completely as if wanting to turn off this all happened while driving on the road and randomly happened…please help..very Concerned

Lifters camshaft malfunction. Known issue with 2021 GMC Sierra 20,000 miles

After having simple oil and filter, and engine and cabin filter replaced at Alpine Buick GMC in Colorado Springs, CO, I received my vehicle back and noticed a complete difference in performance. It hesitates when accelerating, stays low in every gear, and bounces, and I mean bounces hard, when shifting gears, especially slowing down. When slowing down, as it shifts to the next lower gear, it almost pushes the truck forward against me pushing the breaks. Then, when feathering to accelerate slowly, it almost bounces back up to speed, hesitating until I let off the accelerator pedal a little, and it immediately shifts to about 1000 rpm in gear. I have to push really hard for it to go up a gear, and when it does, it has lost all power. My vehicle doesn’t run right anymore after my service appt. I have brought it to my hometown dealership and...

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle was shaking with the check engine warning light illuminated. The independent mechanic was made aware of the failure; however, the vehicle was not diagnosed or repaired. The contact stated that the independent mechanic had previously replaced the lifters, but the failure recurred. The manufacturer was not made aware of the failure. The failure mileage was approximately 20,095.

While driving home from work around 6 am, my car had multiple warning lights and warning messages come up all of a sudden. Immediately after that I lost my power brakes and steering and was not able to control my car at 40 mph. I was lucky the light I passed was green and there was no other traffic. I was able to bring my truck to a stop after more than a quarter mile by putting all my weight on the brake pedal. The truck was towed to the dealer and has been there ever since.

DRIVING DOWN THE HIGHWAY THE ENGINE STARTED SKIPPING AND STARTED BLOWING OUT BLACK SMOKE, AND QUIT RUNNING IN THE MIDDLE OF THE HIGHWAY. FOUND OUT THE HAD A FACTORY LIFTER DEFECT ON MY MODEL AND A SERVICE UPDATE WAS SUPPOSED TO BE DONE ON THE TRUCK CHANGING OUT THE LIFTERS HOWEVER EVEN THOUGH I HAVE GONE TO DEALERSHIP FOR ALL THE MAINTENANCE THE SERVICE HAD NEVER BEEN DONE OR TOLD TO ME. THIS COULD HAVE BEEN VERY DANGEROUS JUST ENGINE FAILURE THE SERVICE BY GMC N212353840

I was operating my vehicle in northern Minnesota with a temperature well below freezing. Vehicle warning light came on that said "turn off vehicle" which I did. When I went to start it again it would not turn over. It appeared that a large amount of oil had expelled from the vehicle. It was very dangerous as I was in a very remote area with very poor cell service and extremely cold temperatures. I couldn't even run the vehicle to stay warm. The vehicle was towed to the nearest GMC dealership where they examined the vehicle and stated that the seal of the oil filter had blown off. They further stated that the oil filter which was installed by Valvoline was the wrong size. Valvoline tested the Champion oil filter and came back with findings that the filter was the correct size and noted no damage to the filter. Either...

Less than 5 minutes after my husband and 2 children parked the car and came inside, a neighbor walking rang our doorbell to let us know there was something on fire in our driveway. We ran to the back to find his truck engulfed in flames coming from the engine. We quickly called 911 and exited the house/property. The truck continued to burn with 20-25 foot flames and very black smoke for about 40 minutes until the fire department was able to control the fire. The fire was hot enough that the entire engine was significantly burnt, the seats and steering wheel were gone, the glass shattered and melted, and the tires exploded and melted. Thankfully, everyone was out of harms way and safe through this incident. However, it has been extremely traumatic on my family and neighbors and has taken a lot of time and energy to try to...

2021 GMC Sierra 1500 AT4 6.2L engine, Little over 39000 miles, Purchesed May 2021. This is the second time the vehicle has had this issue. The first time was aprox 15000 miles. I reported the issue to NHTSA-ODI on 6 Dec 2021 tracking # 11442943. I was driving down the interstate I heard a rattling coming from the engine (same as I had heard with the first issue). The check engine came on I ask On Star to do a digonsotic report (see attached report). The report indicated a Fuel Management System issue detected advised to reduce vehicle speed and pay load as possible. I was told by GM certified mechanics that this issue could cause the engine to lock up and come to a complete stop on the roadway. I fill that these vehicle are unsafe to operate under these conditions and may cause serious accidents. GM has known...

15000 MILES LIFTER FAILURE IN TRAFFIC HIGHWAY AT SPEED 70 MPH LOST POWER ENGINE FAILED MULTILANE HIGHWAY RUSH HOUR TRAFFIC NO WARNING FAILURE

The contact owns a 2021 GMC Sierra 1500. The contact stated that while operating the vehicle, the dashboard gauges, instrument cluster, and infotainment center malfunctioned and became inoperable. Additionally, while starting the vehicle, there was a loud cranking sound coming from the engine compartment and the vehicle would not immediately start. The vehicle was taken to the local dealer, but the cause of the failure was not yet determined. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 100.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle went into Limp Mode with the check engine, DEF tank, and emission warning lights illuminated. The vehicle was taken to the dealer, and the dealer replaced several unknown sensors; however, the failure recurred. The dealer determined that the computer needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 35,000.

Engine lifters failure, caused ESC light to come on and check engine light and other dash lights. Lack of power from engine causing dangerous driving in traffic.

1 June 2022, while driving, started hearing a clicking noise from front end, under hood. Took to local GM dealer, Mechanic drove with me, and he heard the noise, said he would order a part and safe to drive. So, I went home. 2 June 2022 started same vehicle, a very loud banging, clicking, shuttering noise from under hood, I took back to same dealer, Dealer said collapsed valve lifter. GM service notice says for dealer to fix under warranty. Apparently, a known problem with MANY 2021 GMC 5.3 L engines. PLEASE MAKE GM RECALL THIS ISSUE FOR REPAIRDS

My truck shakes/shutters at random times. while steadily driving at constant speed and/ or shakes/shutters even more when I try to accelerate.

The contact owns a 2021 GMC Sierra 1500. The contact stated that the check engine warning light was illuminated and the vehicle failed to accelerate above 60 MPH. The contact took the vehicle to the dealer who diagnosed that the DEF tank had failed and needed to be replaced. The vehicle had not been repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 4,000.

The contact owns a 2021 GMC Sierra 1500. The contact stated that after starting the vehicle, the check engine light remained illuminated and the vehicle would not properly accelerate while depressing the accelerator pedal. The vehicle was taken to the local dealer who diagnosed that the engine valve lifter was faulty and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 11,000.

While driving, when approaching speed of 40 mph, the engine begins to have dull shutter intermittently as though I am going over pot holes or rumble strips when I am not. Regardless of time or day or weather the truck has performed in this way. I have had it to the dealership twice for the issue. The first time they said they didn’t feel anything and unable to duplicate the problem. The second time, the vehicle was with the dealer for several days trying to determine the other issue it was there for. I requested they again try to recreate the concern. The service assistance asked if I was willing to ride with the technician to see if I could point it out for him. In scheduled a time to do so, when I arrived, the technician was not there. I reside an hour away from the dealership. Making these...

Vehicle has less than 10,000 miles. Started making a loud noise and shuddering in the engine while at speed on the highway. Made it to dealer but was concerned we were going to break down before making it safely there. Service manager strongly suspects engine lifters (he drove it briefly with me and says this is a known issue with this truck & they currently have 3 other trucks in the shop with this same problem. He said parts are a 3-4 month wait and vehicle is not driveable, will break down, but couldn’t say when - could be 10 minutes, an hour, or a day. This happened to me on 2/1/22, while out of town on vacation. An hour on the phone with GM and was passed around to 3 different individuals. GM would not provide a loaner vehicle - leaving me stranded out of state. I had to...

8 lifters in my vehicle needed to be replaced. While driving my vehicle (12/4/21), after the auto stop feature was activated my truck experienced a lack of power and hesitation. I then turned the truck off and upon starting it was making a knocking noise. I immediately checked the oil as I wanted to make sure there was oil in the engine. I had warning lights on the dashboard and drove it about 3 miles to the dealer to be repaired. While driving it to the dealer, it did not sound right and shook. I also experienced a lack of power and was concerned for the vehicle to stall out while in traffic. The dealership informed me this is an issue with the 2021 GMC Sierra with a 5.3L V8 engine. I had seen online that GMC issued a service bulletin to have the lifters replaced in the 2021 GMC...

Can turn vehicle off while in gear (drive specifically). When you let off the brake, the truck acts as if it is in neutral. Discovered in my driveway when accidentally forgot to shift into park when I pulled in and pushed the stop button. Truck turned off, which would only expect if in park (or neutral), let off brake, and it began quickly rolling backwards as if it was in neutral. Fortunately the brakes were working, but had any children been riding a bike on the sidewalk or walking by, my truck may have hit them. Had I been more distracted and not noticed initially, it could have rolled into the road and hit my neighbors truck. This behavior can be reproduced every single time, and I can easily supply video.