2021 GMC SIERRA 1500 Complaints

Vehicle purchased new in 2021; has less than 5,600 miles on it. Service Restraint System indicator light began coming on in September. At first intermittently, then every few seconds. Sent vehicle to dealer for repair on 9/27/21. Dealer states not safe to drive because airbag may not deploy in case of accident.

a lifter went out. While driving on a turnpike going 80 mph the engine starting knocking. The truck had to be towed to a GMC dealership where they confirmed a lifter went bad. the truck is a v8 with 8,000 miles on. the dealership advised what the problem was and replaced 4 of the 8 lifters. No warning was given, as soon as the lifter went out there were all sorts of errors that started showing up including emissions issues.

While driving on the highway my truck started to buck and had a loud engine knocking noise. Speed was greatly reduced so much so that I was going under 45 mph in a posted 65. The check engine light did not come on. While sitting on the side of the highway there was a severe engine knock only when the revs on the engine were increased. Oil pressure and cooling temps were as they should be. The next day on the way to the dealership the engine started knocking. This time the check engine light came on, speed was greatly reduced at this time. After about five miles the knocking stopped and the check engine light went out. The Dealership checked it out and stated the lifters were bad. It seems that this is a known issue with GM. I was told by the Dealership that there were two other trucks ahead of me with the same issue. Also, because this is such a prevalent issue with GM, they cannot keep up with the demand for parts. My Dealership is waiting for a head gasket. GM has known about the faulty parts for approximately two years, and they are only replacing some of the faulty, poorly made parts, hoping the other side of the engine will not develop issues and fail. I feel this is placing the driver and occupants at risk while driving down the highway and not being able to maintain posted speed limits, or just locking up and engine, and coming to an abrupt stop.

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.

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.

Driving the car it started backfiring and then the ESC light came on and the car engine seemed to become erratic as well as steering and braking error messages and the check engine started blinking. Very scary before I got it pulled over and very thankful I wasn’t on the highway etc. I’m seeing all the issues online sounds like the supposed fixes for the 2019 models having issues aren’t solving the problem. I bought mine in April and 4 months later it’s become unreliable.

On 22 December 2020, I received a 2021 GMC Sierra 1500 SLT X31 Truck. The day that I drove it I notice that the Truck was riding as though it had a low Tire issue. It was riding bouncy. I had no low tire light. I checked the Tire Pressure and they all was over inflated. I brought the pressure back to range, but the Truck was riding the same over rough and bumpy roads that the rear end of the Vehicle was shifting from side too side when you hit a bumpy or on rough roads. it felt like the rear end was coming off the ground very frighten. I called GM they assigned a case number and I took the Truck to Three dealership with the same answer that all bolts were tighten to Spec. Ok I get that, but did not address the problem that the truck is doing. I am not comfortable driving this truck especially when you have no I deal when your terrain will change and the back end of y0our Vehicle moves from side to sider on you.

Bought GMC Sierra 1500 brand new. At approximately 2300 miles the engine light started blinking. I took it in and they said they couldn't find anything wrong with it. At 3700 miles it started again and I took it in. It has a bent push rod causing engine failure.

GM has a lifter problem that causes complete engine failure. When this happens the engine completely locks up rendering the vehicle completely shutdown. This is happening over and over in early stages of 2021 Chevrolet and GMC Vortec V-8s. Mine happened at 13000 miles on a 2021 6.2L GMC Denali, and GM is only fixing the problem partially and as I understand with the same defective product that just failed. Also it is known this failure likely will happen again as it is a design flaw. If this happens in the wrong traffic situation it will be very dangerous. I am very concerned. When my vehicle was towed to dealer they had 7 other 2021 complete engine failures just like mine waiting for repair.

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving in inclement weather, the vehicle stalled without warning. The contact looked under the vehicle and saw that engine oil was leaking from a puncture in the oil pan. The vehicle was towed to the local dealer however, the cause of the failure was not yet determined. The manufacturer was notified of the failure. The failure mileage was 5,800.