Complaint volume
487 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
487 consumer-submitted complaints on record for the 2021 GMC Sierra, grouped by component category.
487 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 104 complaints, with an average reported failure mileage of 51,093 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 156
POWER TRAIN 59
ENGINE AND ENGINE COOLING 37
POWER TRAIN,ENGINE 29
ELECTRICAL SYSTEM 26
UNKNOWN OR OTHER 14
STEERING 13
UNKNOWN OR OTHER,ENGINE 12
ELECTRICAL SYSTEM,ENGINE 9
SERVICE BRAKES 9
487 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| 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 | 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 | 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 | 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 | UNKNOWN OR OTHER,ENGINE | The transmission is constantly whirring, rattling, and screeching. | Crash: No Fire: No | Unknown |
| 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 | 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 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 | 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 | 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 | 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 | 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 | 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 |
| 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 | 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 | POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM | Engine power reduced, could not accelerate, fuel pump issue and was bucking the engine Went to dealer and complained as gmc not working to help me, dealer fixed issue but said no other complaints out there and car was fixed, gmc called me several times and keeps saying no issues with the vin associated. The car was fixed but I am stuck with a truck that is probably not saleable once these issues continue. This issue happened initially with 30 k on it and dealer could not find the issue and this times at 61500 happened again | Crash: No Fire: No | Unknown |
| Apr 2025 | POWER TRAIN,ENGINE | was getting on the interstate whenever i hit 70 mph just heard a hard knock in the engine and truck was driving rough. the truck it self dropped to 60mph. before it occurred there was no check engine light on or anything. after i had the dash light up with engine light, brake light, stability light. about a week later took it to the dealer they said it was fuel injectors they replaced it took them about 2weeks but the problem wasn’t resolved but then stated it was the lifters which they said it almost common for this to happened. so i took it somewhere else to get replaced and they said yes it was the lifters and i needed to replace the camshaft because when the lifters go out it will damage the camshaft. all they did to diagnose my problem was hear it was ticking and the knocks also with the codes from the dealer diagnosis. after my repairs it was expensive least to say | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | Engine light came on, went to the dealership where I bought the truck less then two weeks prior. The Chevy dealership ran diagnostic test on it. They said it was the Engine Coolant Control Valve. This is a common problem with the 3.0 Duramax diesel engine. I belong to a group on Facebook with the same truck as mine. they are all having the same issue. We are waiting for a recall. the part is on back order and cost $300 just for the part plus labor. I bought the extended warranty and they said it did not cover this part. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | Had the car since 2021. Recently started shaking while driving over 45 mph. Took the car in gmc dealership where they told me it’s an engine issue and need a brand new engine. How would I need an engine having the car for 4 years? And there is no recall? | Crash: No Fire: No | Unknown |
| Apr 2025 | POWER TRAIN,ENGINE | July of 2023, lifters failed on left side of engine. Lifters replaced and cam shaft replaced. January 2025, lifters failed on right side of engine. Replaced. March 2025. Engine seized on interstate. Truck lost all power while driving, no warning signs prior. Dealership has no rental vehicles and we are not old enough to rent from a third party company so family had to drive 9 hours to our location so we wouldn’t be stranded. Three times this truck has failed us. GM is putting in a new motor as it’s still under warranty, but the new motor has no additional warranty. So basically this new motor will be warrantied for less than 7k miles. They cannot say if the new motor has the remanufactured lifters or not. So we could be facing the same exact issues. Can’t ever get ahold of anyone directly though GM. | Crash: No Fire: No | Unknown |
| Apr 2025 | ELECTRICAL SYSTEM,ENGINE | Transmission recall was performed at a gmc dealership. Vehicle has been the the shop repeatedly since. Coolant control valve crank case position sensor new catalytic converter and dpf system. New low temp coolant loop pump. In the shop now for another low temp coolant pump that’s been shorted out. Seems to have on going electrical issues since recall was performed | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 70 MPH, several unknown warning lights illuminated, with the message to shift to neutral displayed. The contact pulled over to the right side of the road and attempted to restart the vehicle; however, the vehicle failed to respond as needed. An unknown dealer was contacted. The contact stated that the failure had occurred on several occasions. The vehicle was towed to the dealer, where it was diagnosed that the engine was damaged and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and offered a monetary payment. The approximate failure mileage was 80,000. | Crash: No Fire: No Towed | 80,000 |