2020 GMC SIERRA 1500 Complaints

Engine started rough idle, reduced power, poor acceleration, ticking and knocking noises, and a check engine light and a few other lights came on the dash. Safety was not a risk at time of incident. Problem has NOT been diagnosed yet BUT have done a ton of research and it’s all leading towards lifter failure/misfire issues. No warning lights or symptoms prior to sudden problems.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while attempting to start the vehicle, the vehicle vibrated abnormally. The engine warning light was illuminated. The contact stated that on another occasion, while driving at an undisclosed speed, there was an abnormal knocking sound coming from the engine. There was no warning light illuminated. The vehicle was towed to the dealer; however, a cause for the failure was not found. The vehicle was not repaired. The failure recurred and the contact stopped driving the vehicle. The manufacturer was not made aware of the failure. The failure mileage was approximately 110,000.

This car had lifter motor failure at 135K miles and Transmission failure at 145k miles, the torque converter of this truck is the culprit of many issues as the lifter issues.

I purchased a 2020 GMC Denali Sierra 1500. My oil light has came on twice and I have taken it into the dealer and dealer has said that that's normal. That car loses oil. I'm retired so I do not utilize the vehicle every day I think since I've had the vehicle I've put on several thousand miles very very low mileage put on. And I'm being told that I need to check the oil basically before I take the vehicle anywhere. During the first time when I bought the vehicle in when the light came on the mechanic said in the paperwork from GMC service that my engine oil was extremely low. This last time that I did take it in, I have some type of mechanical background, so I pulled the dipstick out and it was halfway full with oil. I took a picture of that dated the picture and said I took it in before service while when I took it into the service department of course when I came home, they said that everything's fine and so on and so on and that didn't sit well with me. So I went ahead and let the car settle. Let the car cool down several hours later. I went ahead and checked the dipstick and the dipstick was full. They went ahead and put oil into my vehicle and told me that everything's fine. And I have noticed that there are lawsuits out in regards to oil consumption issues on these vehicles. When somebody spends the amount of money they spend for these vehicles we should not have to be checking the oil almost every time we drive it. I've had multiple vehicles on 50 years old and I've never had to check the Oil like it was 1914 before you go on a trip or even drive your vehicle. I am not trying to blame the Dealership only being told that everything's fine but GMC the company needs to rectify this problem because there is going to be a time that people are going to forget about the oil and burn up an engine and then you're putting them out thousands of thousands of dollars because of a mistake GMC made they're trying to cover it up as you see with the current recall in regards t

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission unexpectedly downshifted. There was no warning light illuminated. The vehicle was able to restart. The vehicle was taken to the dealer, where it was diagnosed and determined that the transmission had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 70,000.

I was driving about 45 mph when the vehicle started to brake on its own. Message center said "Brake Failure max speed 62 mph". I had to move the vehicle, so I continued forward. It was still trying to self-brake, i decided to stop and turn ignition off so computers could re-set but I had no brakes. I had to stand on brake pedal to get it stopped. Turned ignition off and restarted. The problem was gone, but it happened again 2 weeks later. Took to dealership where purchased and they said it needed a computed recalibration. Something I didn't know about. They charged me $200 to recalibrate the computer. My issue is the danger of not having brakes, not the $200. How many similar vehicles could this happen to?

The contact owns a 2020 GMC Sierra 1500. The contact stated while driving 5 MPH, the vehicle made an abnormal popping sound. The check engine and the ABS warning lights were illuminated. The messages "Parking Brake Service" and "ESC Service" were displayed. Additionally, the contact stated the vehicle experienced a reduced fuel range. The vehicle was taken to the dealer, where it was diagnosed that the lifters had fractured, causing damages to the engine. The dealer determined that the engine needed to be replaced, and the part was ordered. The vehicle was not repaired. The contact related the failure to NHTSA Action Number: PE25001 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure. The failure mileage was approximately 80,100.

Motor failed with no warning, motor was replaced at a GM dealer for $12,000. Mechanic stated he believed it was a main bearing failure. Not under warranty.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle started pulling to the left, and the vehicle ended up in the next lane. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to duplicate the failure. The vehicle was not repaired. The contact stated that the vehicle had been taken to the dealer six times because of the failure. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 17,000.

Our middle seat belt has stopped working in the back seat- we have not had it replaced yet. No damage was done on it by us, but will not click into the buckle. Driving on the hi-way engine started making awful noises. We pulled over and had the truck towed to Royal Moore GMC in Hillsboro Oregon as we didn't want to cause any more harm to the engine. Royal Moore GMC informed us the engine rod bearing failed on [XXX], leading to breaching of the engine block by the rod. This caused us to replace the entire engine at the cost of over 13,000$ and no vehicle for over 3 months. (Along with engine replaced they told us we had to replace the O2 sensor as the light came on after the engine was replaced). We had to take a hardship loan to get the engine replaced, and had the truck back for 1 day before we had a o2 error l light came back on. At this time (May 5th) we are still waiting for our truck back. Royal Moore doesn't know why the engine light is on- and contacted TAC for GMC. We also contacted GMC multiple times when we were waiting for the engine. They have offered no help to us besides empty promises to call us back later. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)