Problems · by component
2021 GMC Sierra 1500 engine problems
322 owner complaints to NHTSA about the 2021 GMC Sierra 1500 cite engine, 54% of all 596 complaints for this model year.
Complaints
322
54% of all complaints
Crashes
0
Reported by owners
Fires
5
Reported by owners
Injuries
1
Reported by owners
What owners say about the engine
Verbatim from NHTSA complaints, newest first
“Engine locked up while driving down the road at highway speeds. Lost all power and had to pull to shoulder of road. Was towed to dealership and confirmed engine locked up and covered under special recall. Was looked at a few months back and passed the recall test on engine. No lights or signs of engine failure before failure.”
“My 2021 GMC 1500 Sierra has the 6.2L motor that has significant known issues with catastrophic engine failure involving the camshaft and lifters. The engine in my truck has suffered the same failure but for some reason my VIN is not included in the recall of nearly 600,000 GMC trucks. I called GMC Customer Service and was told bluntly the recall was VIN specific and I would have to bear the 14,000 dollar repair. This is unacceptable since GMC is under federal investigation for knowingly and negligently manufacturing a flawed motor.”
“My vehicle fits Special Coverage N252508341in every way, except the dealership tells me that my VIN is not covered. I drive a 2021 GMC Sierra 1500 with approximately 61,000 miles. This weekend a Check Engine Light illuminated with P1010 code. All the symptoms described in Special Coverage N252508341 were exhibited: the vehicle displayed 'Engine Power Reduced', and the electric cooling fans began operating at full output. I have taken the vehicle to Cronin GMC here in Perrysburg and it has been diagnosed with Coolant Control Valve failure that requires replacement. They state that my VIN is not covered by Special Coverage N252508341 and that I must pay full price for the replacement. I am writing to extend this coverage to my vehicle so I can either receive a no-charge repair or seek reimbursement after I pay for the service.”
“Service light came on because the brake petal would push back when I tried to start it. At times, I had to push down all the way almost to the floor and then it would start. If I eased up slightly or did not push all the way, the truck would hesitate to start. I brought it in to Courtesy GMC of [XXX]. They found metal debris in oil. The car warranty did not want to replace the entire engine as General Motors' bulletin had stated as a corrective solution. They only wanted to replace the camshaft and rocker arms because [XXX] did not tear down the engine to the point of failure. [XXX] stated that they did. After going back and forth with EasyCare (myself and [XXX]) I authorized the repairs EasyCare suggested. XXX, a Service Brake Assist message came on. I brought it to [XXX]. They rectified the issue. XXX,Truck stalled getting off XXX at light. Truck kept turning on and off. I put it in park and was able to turn in on. As I was driving the truck was rocking back and forth as I pressed the gas pedal. I was able to pull into the Super1 Foods parking lot. Trucked stalled halfway into parking lot. After two attempts to turn off and start truck I was able to pull it…”
“Loud engine knock, made it to dealer. Dealer confirmed engine failure as defined in the applicable recall. No idea when a replacement can be aquired. Unable to drive anywhere due to design and manufacturinf issues I did not cause.”
“The contact owns a 2021 GMC Sierra. The contact stated that while driving at 60 MPH, a reduced power mode warning message unexpectedly illuminated, and the vehicle unexpectedly entered limp mode. The contact stated that the temperature gauge indicated a high temperature and the vehicle was overheating during the failure. The vehicle was taken to the dealer, where it was diagnosed that the control valve had failed and needed to be replaced. The vehicle was not repaired. The dealer informed the contact that this was a known failure and escalated the issue to the manufacturer for further assistance. The contact stated that the failure was associated with Technical Service Bulletin (TSB) N252508340 and believed the repair should have been covered under warranty. The manufacturer was made aware of the failure via telephone and website. The contact was also referred to NHTSA for further assistance. The approximate failure mileage was 110,900.”
Showing 6 of 322 reports. Read every report on NHTSA.gov.
Data from NHTSA Complaints API (owner reports, unverified) · synced Oct 28, 2026NHTSA vehicle page
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.