Complaint volume
519 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
Complaint records
2021 GMC Sierra Complaints
519 consumer-submitted complaints on record for the 2021 GMC Sierra, grouped by component category.
519 Total complaints
5 Crash reports
6 Fire reports
2 Injury reports
Complaint data reflects consumer-submitted reports. A complaint is not proof
of a defect, recall, or manufacturer fault. Enriched severity fields come
from official bulk records when the complaint can be matched by ODI number.
Buyer interpretation
How to use these complaints before buying
Complaint records are most useful when they turn into inspection points, seller questions, and comparison checks against nearby model years.
Pattern to inspect
The most common categories are engine, power train, engine and engine cooling. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity flags
Enriched records include 5 crash reports, 6 fire reports, 2 injury reports, and 0 fatality reports. These fields come from complaint records and should be read in context.
Mileage clue
Mileage is available on 109 complaints, with an average reported failure mileage of 51,910 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to engine, power train, engine and engine cooling?
- Can I see recent maintenance and repair records?
- Has the vehicle ever been towed, involved in a crash, or repaired for the same issue twice?
- Can we also check the recall record for this 2021 GMC Sierra?
Used-car checklist
Use these complaints before the test drive.
Build a buyer checklist to turn these issues into questions and inspection points.
2021 GMC Sierra
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2021 GMC Sierra complaints?
5 Crash
6 Fire
2 Injury
0 Fatality
30 Towed
3 Medical attention
What are the most common 2021 GMC Sierra complaint categories?
ENGINE 169
POWER TRAIN 64
ENGINE AND ENGINE COOLING 40
POWER TRAIN,ENGINE 29
ELECTRICAL SYSTEM 26
UNKNOWN OR OTHER 16
STEERING 13
UNKNOWN OR OTHER,ENGINE 12
ELECTRICAL SYSTEM,ENGINE 10
SERVICE BRAKES 9
519 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| May 2025 | POWER TRAIN,ENGINE | While driving on the highway the engine died forcing me to change lanes to cross traffic and coast to a stop on the shoulder. It was dangerous and unexpected. It would not restart so I had to have it towed. Inspection revealed the bearings had gone bad in the engine and the engine would have to be replaced. I had to wait 2 and half months for an engine. | Crash: No Fire: No | Unknown |
| May 2025 | STEERING,WHEELS | I was driving approximately 25-30 mph coming over an overpass moving into the right hand lane when my truck right front end failed. The steering and brakes locked up for approximately 50’ until I hit the curb for the sidewalk and stopped. I safely exited the vehicle checked the left side of my truck for damage and didn’t find anything. I walked around the back of my truck and came to the passenger side where I found my right front wheel and tire completely broken away from both upper and lower control arms, the ball joint broke and failed as well as the brake line. If I was driving on the highway at 65-75 this catastrophic failure could have resulted in a fatal collision. The night before my [XXX] daughter and I returned from her outdoor Ed trip in Sausalito and we drove an hour home to Napa on [XXX] and [XXX] . I thank god this didn’t happen with her in the car on the highway. I had my truck towed to Jimmy Vasser Chevy in Napa so I can see if the extended warranty will cover the repairs since it was an obvious catastrophic failure of the whole right front end. It’s still sitting there. The extended warranty inspector came Friday to take pictures of the damage INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) | Crash: Yes Fire: No Towed | Unknown |
| May 2025 | ENGINE | The vehicle will crank and not start. Dealership said they cannot replicate the fault. Same problem occurred after with dealership not helping. I am a US Soldier currently stationed in Germany and continue to have the same problem every 2months. It will crank and not start. The truck will start on the second attempt after cranking for about 20seconds. The continued issue can permanently damage expensive repair parts that I will not be able to afford. I know I am not the only one with the same issue as I have talked to others and have no solution for this. | Crash: No Fire: No | Unknown |
| May 2025 | POWER TRAIN | Was driving vehicle on freeway at normal speeds and the vehicle lost propulsion. Engine was off and vehicle said to shift to neutral and restart. I was able to exit the freeway safely (barely) to the median. Vehicle would not restart. It has the L87 engine which is under recall. Vehicle is at dealership submitted under the recall. I am being told there is "no remedy" and "no parts" and given no timeframe for any fix to be completed. I am still liable for the payments, insurance and this is our only vehicle in a single father of three family. | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | Engine failed GM made me pay for a new one. Second engine failed due to mechanics did not change out radiator. I now have a third motor with a recall. This vehicle has cost me a lot of out of pocket expenses, I believe GM owes me for the depreciated value plus lost wages. Maybe a buy back I'm not sure. | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | My vehicle suddenly stopped working in the middle of an intersection. A screen notification prompted me to restart it, so I pulled over safely, as there were no other vehicles nearby. However, I worry about the potential danger if this had happened on a freeway. After waiting, I tried restarting the vehicle, but it still wouldn’t work. The next day, I received an email from Carfax about an open recall for my vehicle due to engine issues, matching the symptoms I was experiencing. I scheduled an appointment for 4/28, and had the vehicle towed to Elk Grove Buick GMC. At GMC, they couldn’t offer immediate solutions, needing to diagnose the vehicle first. This process took about four days. During this time, I was advised to contact GM, as the vehicle was affected by the recall. I submitted a case to GM on April 28th, requesting compensation for a rental or loaner vehicle, a truck for my business needs. Without it, my business operations would suffer, leading to revenue loss. The dealership’s diagnosis found the engine seized due to a failed bearing. GM contacted me about the recall, initially mentioning the lemon law and a potential buyback, which I hadn’t considered. After I expressed a desire to repair the vehicle, they contacted the dealership for more information. GM later clarified that the vehicle wasn’t covered under the recall, citing the cause and symptoms as not meeting the recall’s criteria. This seems contradictory, as a failed engine doesn’t necessarily contradict the recall. GM stated they couldn’t provide a remedy, leaving me responsible for repair costs, and noted my vehicle’s 70,000 miles exceeded the power train warranty. Recall claims dealerships will inspect and, if necessary, repair or replace the engine. It’s confusing why my vehicle isn’t covered for repairs or assistance under this recall despite the engine failure. What is the law in terms of warranty as I was under the impression that warranty status is irrelevant in an active recall vehicle. | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | Coolant Control Valve (ccv) on these vehicles are notorious for breaking down/ becoming non-operative. I have been waiting for a part for months. | Crash: No Fire: No | Unknown |
| May 2025 | UNKNOWN OR OTHER,ENGINE | We NEVER RECEIVED A RECALL NOTICE FYI . This vehicle has been serviced consistently.never an issue. Driving on [XXX] very busy! Truck literally stopped in the middle of the freeway in a very bad location. Desert. Noon. Kids with us. Could have died. Preliminary eval: engine seized, piston rod failure. Not sure the rest - we have to tow it home first. Failed while traveling. Please call for more information if needed. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) | Crash: No Fire: No | Unknown |
| May 2025 | POWER TRAIN,UNKNOWN OR OTHER,ENGINE | I've noticed rough or jerky gear shifting when accelerating, rough and reduced propulsion, loss of power. Dealership repaired power torque converter but the truck continue to have the same symptoms. | Crash: No Fire: No | Unknown |
| May 2025 | UNKNOWN OR OTHER,ENGINE | The transmission is constantly whirring, rattling, and screeching. | Crash: No Fire: No | Unknown |
| May 2025 | STEERING,ENGINE | The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at slow speeds and accelerating out of the neighborhood, the vehicle experienced a loss of automotive power, with the check engine and EPS warning lights illuminated. The contact was able to drive the vehicle back to the residence. The vehicle was then towed to a local dealer where the vehicle was diagnosed, and the contact was informed that the engine had failed and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 103,000. | Crash: No Fire: No Towed | 103,000 |
| May 2025 | POWER TRAIN,ENGINE | I was coming home after work, before I got home I stopped at the gas station to fill up my tank, after I filled up my tank I start driving home but while on my way home my truck wasn’t speed as I expected and it only goes maximum of 10mph and I was confused, I stop and check my truck see what happens but there is no sign since there was no sign I get on my truck and start driving to home, after I got home I was trying to revers parking and that’s when I realized my truck wouldn’t reverse. I thought of if it happened while I was driving on highway and my truck stopped on the middle of highway I could have lost my life. I called the dealer and the dealer told me it might be because of the engine then next day I took it to the shop and they couldn’t figure until couple days later and it took them around 2-3 weeks to replace my transmission. Luckily I had the power train warranty when I bought the vehicle and it don’t cost anything. If I didn’t have that power train warranty everything will come out of my pocket, the cost was around $6-7k. | Crash: No Fire: No | Unknown |
| Apr 2025 | POWER TRAIN,ELECTRICAL SYSTEM,ENGINE | While driving my truck with my wife and two young boys, the truck engine completely shut off while operating it. We were stuck in the middle of the road and had to cautiously wait until we could move the vehicle out of the way. The engine locked up. Now they are trying to repair the engine with the same exact engine that is on recall and potentially put me and my family in the same dangerous position. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | Vehicle has less than 64,000 miles and seems to be having engine issues. ESC message with engine power reduced. Cannot even drive the vehicle any longer. Cannot get it into a shop for a month and will have to have it towed. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and making a turn, the vehicle made a loud banging sound and the vehicle shut off. No warning light was illuminated. The vehicle was towed to an independent mechanic, who determined that the engine had failed and 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 VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 80,000. | Crash: No Fire: No Towed | 80,000 |
| Apr 2025 | ENGINE | The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 65 - 70 MPH, there was a knocking sound coming from the vehicle and the vehicle shut off. There were unknown warning lights illuminated. The vehicle was towed to an unknown location. The local dealer was contacted. The vehicle was not diagnosed or repaired. The vehicle was taken to an independent mechanic who determined that there was a solid engine bottom and bearing failure. The contact was informed that the engine needed to be replaced. The vehicle was repaired. but the failure recurred, and the vehicle failed to start. The manufacturer was contacted and informed of the failure. The failure mileage was approximately 83,000. | Crash: No Fire: No Towed | 83,000 |
| Apr 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2021 GMC Sierra 1500. The contact was notified of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was made aware of the issue and confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available. | Crash: No Fire: No | Unknown |
| Apr 2025 | POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE | Tried to accelerate and heard a loud pop and the truck didn’t accelerate. Pretty much went idle in the middle of the road. The check engine light, the traction control light, and the ABS light all came on. I would press on the gas and it would rev but nothing would happen till a few seconds later the RPM’s would shoot up and you could tell it was trying to get going but didn’t very slowly and I would hear a clicking noise every time it was around the second gear. It put my children and myself in danger because traffic was heavy with vehicles going 70+mph merging into one lane. Took it to a dealership and they stated it was the the push rod and camshaft were damaged and all 16 lifters should be replaced and camshaft also. No, the vehicle has not been inspected by any of those except a car dealership and a mechanic. This problem first appeared the day it happened and continued after. Even took it to a mechanic and had all 16 lifters changed and problem still persists. Spent over $6,000 on a brand new truck and it is still undrivable because every time you get in to drive it the cylinder #2 misfires. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | I wanted to reach out to see if there is anything in addition to the lemon law. I bought a 2021 GMC Sierra with 38,000 miles on it around March of last year. There was a motor defect which was covered by the warranty. I was driving and it stopped in the middle of the road so I had to safely maneuver out of the main road. The truck was towed to my house with 45,184 miles on it, until the GMC dealership could take it in to inspect. They did take a while to get me a rental because everything was backed up. They said they could rent me out a truck due to not being their brand and that it only covers a certain amount. It got taken in by the dealership on 7/15/2024 and ended up getting the truck back repaired on 8/27. I did get the truck back and have been having it, I am just worried about it breaking down or anything of that nature. I just wanted to know if there is any further process I should do or since they repaired it there should be no issue. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | I had purchased a 2021 GMC Sierra equipped with the 6.2 liter motor in October of 2021. Within two weeks, my engine was experiencing problems. There was no service lights on the dash, and my truck suddenly shut off while on a busy road. I was able to coast to the side of the road, however it was a driving lane with no shoulder which made the situation dangerous. I was able to restart the engine after some time, and eventually get the vehicle off of the roadway, thankfully I got out of the driving lane without being struck by another vehicle. The truck had approximatley 1000 miles at this time and was brand new. I ended up needing a complete engine replacement due to failed crank bearings and connecting rods. I was told it was a crankshaft issue. After the complete motor replacement, sometime during the next year I was experiencing oil burning issues. On this second motor, a GM dealer had to completley rebuild the top end of the motor and install new piston rings. This is now a total of two motor failues in under 30,000 miles. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | First engine blown 31,904 miles, Lifter failure. Replaced with re-manufactured engine. Second engine failure at 68,000 miles, Piston rod failure. Piston blew thru engine block and engine bay caught on fire. | Crash: No Fire: Yes | Unknown |
| Apr 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving approximately 55 MPH, the vehicle suddenly experienced a loss of automotive power. During the failure, the message "Shift into Neutral to Restart" was displayed. The vehicle was later towed to the local dealer, who diagnosed that the piston bearings had seized, causing damage to the engine. The engine was replaced along with the radiator, oil cooler and oil cooler hoses, intake manifold, mega fuse, and starter. The manufacturer was notified of the failure. The contact was informed that the VIN was recently included in the NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 122,691. | Crash: No Fire: No Towed | 122,691 |
| Apr 2025 | ENGINE,FUEL/PROPULSION SYSTEM | Motor seized up while going around 65mph. Truck lost all power and would not start brought to dealer and they said that it was the crankshaft bearings and something with the connecting rods, the deal told me that they don’t know what to do and is waiting on GM. There is a recall for these issues but no fix. I’m just waiting for the dealer to tell me what’s next but they don’t even know. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2021 GMC Sierra 1500. The contact stated that there was an abnormal ticking sound coming from the vehicle while idling. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The contact was then notified of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was not made aware of the issue. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 33,000. VIN tool confirms parts not available. | Crash: No Fire: No | 33,000 |
| Apr 2025 | POWER TRAIN,ELECTRICAL SYSTEM,ENGINE | See attached vehicle repair orders/Carfax/vehicle registration. The trucks transmission has been slipping/jerking hard since I pulled off the lot at dealer ship. Its burning oil no leaks has been doing so since the day I drove off the lot at dealership. I have asked to fix or address and problem still exist. They sold vehicle as everything was working The Left head light wasn’t working the day I drove off the lot didn’t notice until I got home I reached back out to dealer to explain and said light had a short in kept truck for almost a week said the were going to replace the head light and never did. The remote start wasn’t working the same day i purchased the truck but sold it as everything is working. I went to try it as I was getting ready to leave dealership and did nothing. Then I discovered the fog lights were missing, and dealer said oh there was never any in the truck but if you read the service paper work there was lights in truck. Took truck back to address the issues the next day or so after purchase I was told to bring truck back the following week. All the conditions still exist and I should not be having any of these issues as the sold vehicle nothing wrong. They even had an October inspection saying everything was SAT but I get in truck no fog lights and left head lamp is not working but they performed an 360 inspection….yeah no way… This truck is doing the same as my 2021 chevy Silverado but there is nothing wrong with vehicle according to dealership. Sold A Lemon if you asked me… ***Highlighted in yellow is a recall that the dealership has not done nor can they find anything on the recall**** *****Power train**** Recall date 2024-10-24 Recall no. 24V797000 General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel en | Crash: No Fire: No | Unknown |