10.0
really awful- Crashes / Fires:
- 0 / 1
- Injuries / Deaths:
- 0 / 0
- Average Mileage:
- 147 miles
About These NHTSA Complaints:
The NHTSA is the US gov't agency tasked with vehicle safety. Complaints can be spread across multiple & redundant categories, & are not organized by problem. See the Back button — blue bar at the very top of the page — to explore more.
I own a 2021 GMC Denali with a 6.2L V8 L87 engine and 45,500 miles. I have confirmed the presence of metal shavings in the oil and oil filter, indicating that the engine is beginning to fail. When I took the vehicle to my local dealership, I was informed that there is currently no fix for this issue and was advised to continue driving the vehicle. This poses a serious safety risk-?"not just to me and my family but also to others on the road. A sudden loss of power could lead to a dangerous accident, and I do not want to be responsible for something preventable that could harm innocent people. My concern is that GM is aware of this engine issue but has instructed me to keep driving the vehicle, despite the known defect. How can GM be allowed to avoid accountability for such a critical safety matter" If a fatal accident were to occur, would the responsibility fall on GM or the NHTSA for failing to act" It-??s also troubling that GM continues to profit by selling new vehicles, including the 2025 models, with similar issues, all while neglecting to provide solutions for affected customers like me. I purchased this $80,000 truck in good faith, but now no dealer wants to trade or buy these trucks without me taking a significant financial loss-?"something GM should be responsible for. As a taxpayer, I find it unacceptable that we bailed out GM in the mid-2000s, yet they continue to disregard accountability for their actions. I urge the NHTSA to take this issue seriously. A specific deadline should be set for GM to resolve this issue, and they should face daily penalties for every day they fail to provide a fix. If no resolution is possible, full refunds should be mandated. Please address this issue promptly, as it affects real people-??s safety and financial well-being every day.
- Debary, FL, USA
Was informed from by GM that my vehicle is involved with a recall an still hasn't been repaired
- Statesville, NC, USA
Engine experiences missing when accelerating in lower speeds...also now, and since driving for a few thousand miles, f umes are entering cabin frequently and causing nausea, 'headaches and burning of mouth, lips and eyes.....all the time. My youngest granddaughter got sick and so did my oldest son just this past weekend! As far as I know, police or dealership never inspected, nor did they acknowledge it! No warning lamps appeared
- Stephens City, VA, USA
- #5 injector failure, no. - Once the injector failed, the vehicle would violently shake when trying to accelerate. - Yes, was not covered under factory warranty but replaced by third-party extended warranty. -Yes, replaced by the dealership. -No warnings prior, once the injector failed warning for brake system check and vehicle mileage limits set in warning.
- Ridgeville, SC, USA
The engine coolant flow control valve position sensor is faulty. I brought mt truck in to my dealership and I have been waiting for over a month to get the issue fixed because -??the part is on backorder-??. This issue makes my truck sound like a jet engine because it makes the truck think overheating and causes the fan to come on at full blast. After drivinf for awhile it goes into -?? reduced engine power mode-?? which is totally unsafe because it reduces the horse power to that of a lawn mower. It takes about 30 seconds to get from 0-60, so merging onto freeways or in conditions where you need extra speed its completely useless and increases the scenario of being rear ended, immensely.
- Medford, NJ, USA
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.
- St Amant, LA, USA
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
- Flanders , NJ, USA
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!
- Tehachapi, CA, USA
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 they say it runs fine and nothings wrong. But there is something wrong with it.
- Winter Haven, FL, USA
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 deal with this. The car sat in our driveway for over 2 weeks with a very potent smell causing headaches until GM and our insurance finally investigated. There is damage to our siding, driveway, landscaping, basketball hoop, trampoline, and neighbors fence. The car was only 2 years old and scares me how quickly it went up in flames and how much worse this could have been either 3 minutes earlier or if it was parked in our garage.
- Kirkwood, MO, USA
15000 miles lifter failure in traffic highway at speed 70 mph lost power engine failed multilane highway rush hour traffic no warning failure
- Plymouth , MI, USA
Within 100 miles after purchasing this truck from GMC (used with 74K miles)I got messages both on my phone and later through inspection at GMC service center that the DEF system had a problem. The check engine light came on then off as well.I was getting messages saying I only had so many miles before the DEF system needed more fluid even though the tank was full or near full. The dealer here in Tucson indicated there was a bulletin on this problem and ordered parts for the repair. I was informed it was not a recall and I would have to pay over $800 for this repair. To date the dealer has had my truck for 2 weeks. Additionally, another message said insufficient coolant flow so they are installing a new coolant pump to be paid for by an after market warranty which I purchased at the time I bought the truck. This repair is over $1000
- Tucson, AZ, USA
Less than 300 miles on the vehicle and it has thrown an error code P2B60. Relating to the engine coolant flow control valve position sensor. I have taken it to my local GM service center and they cannot see me for weeks. As of this morning the check engine light has disappeared but my fuel economy has severely decreased. It seems suspicious and possibly dangerous that it showed a check engine light with a warning of reduction in engine power the night before and disappeared in the
- Canton, GA, USA
I have had my gmc sierra 1500 for 2 weeks and it has less then 200 miles on it the first week I lost power the check engine light, air bag and traction control light started flashing and since then my engine light has be solid with code P0300 and it will intermittently loss power and start flashing. The dealer has it now but cannot figure out the issue. Total unacceptable for a brand new vehicle.
- Fort Drum, NY, USA
The truck has 7500 miles on it and the check engine light keeps coming on then goes back off. It is impossible to schedule service as the light goes off before it gets to dealer. The when driving the truck many times the check engine light will flash for a minute or so and then remain on steady. This is very frustrating and the dealer has found nothing. It has happened probably 10 times since the truck was new and continues now. The truck was just serviced and the dealer found nothing causing this.
- Arcanum, OH, USA
While driving during winter conditions with temperature at 3 degrees on a residential street with limited traffic, the diesel fuel in the fuel filter gelled up which caused the vehicle to display reduce power mode and then immediately shut off and would not start. The vehicle coasted to a stop in the middle of the street while in traffic. The owners manual lists utilizing top tier diesel which I did. While additives are not normally needed in most states to fuel for freezing conditions evidently they are needed in Oklahoma. The fuel filter housing is the only place where the fuel gelled up, which appears to be a theme in most GMC diesel trucks and does not effect fuel in the fuel tank due to volume. GMC has done nothing to improve the design or increase insulation to the thin fuel filter housing. If I had been in fast traffic on the interstate it would have resulted in an accident and possible loss of life.
- Broken Arrow, OK, USA

- Katy, TX, USA