2020 GMC SIERRA 1500 Complaints

View complaints related to 2020 GMC SIERRA 1500. The complaints found here are submitted by actual consumers with first hand experience. There are more than 440 complaints submitted for the 2020 GMC SIERRA 1500. You can submit your own complaint to the NHTSA or call the Hotline, Monday-Friday 8am to 8pm at (888) 327-4236, TTY: (800) 424-9153.

  • 2020 GMC SIERRA 1500
    - Lacombe, AL

    I experienced lifter and camshaft failure on my 2020 GMC Sierra equipped with the 6.2L V8 engine at approximately 72,000 km. GMC denied warranty coverage as my factory warranty had expired only four months earlier. The repair cost me nearly $10,000 out of pocket. My vehicle has been meticulously maintained with regular oil changes performed at my local GMC dealer every 5,000 km, and it has always been fueled with premium gasoline as recommended by the manufacturer. The engine failure was sudden and unexpected. All lifters and the camshaft were replaced during the repair. Since the repair, I have noticed intermittent RPM fluctuation under light load conditions. I am currently working with my dealer to diagnose whether this issue is related to the recent engine repair or a transmission flush that was performed at the same time. I am extremely disappointed in GMC’s handling of this situation. Despite this being a well-documented issue with the 6.2L engine, I received no goodwill assistance or warranty consideration from GMC. While my dealer provided a partial discount on parts and labor, I was still responsible for nearly the entire repair cost. I hope GMC and NHTSA will review this matter closely, as owners should not be facing such expensive failures on well-maintained vehicles with this engine.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Cedar Rapids, IA

    A lifter in my cylinder is bad and damage to my cam shaft. This truck also has the 6.2L engine that was recalled for other GMC Vehicles.My safety was put at risk as I was driving it and it started smoking. I have had 2 different mechanics look at it. One mechanic was an independent business, the other was a certified GMC dealer. There was no warning lamps or messages.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - FORT WORTH, TX

    Rod bearings spun and engine locked up while driving 70mph on the freeway. I was in traffic, and had to work my way over and off to the shoulder of the road. The engine was diagnosed and replaced by Hiley GMC at a cost of nearly $5,000 out of my pocket. This was at approximately 63,000 miles. Just out of warranty. No loaner vehicle provided. I was without my truck for 2 months. There were no warnings at all. No lights or noises of any kind. Rod bearings spun again on the replacement engine approximately 35,000 mile later. It happened same as before. Driving on the freeway at 70mph, and the engine seized. No power steering, no warning noises or lights. I had to coast across lanes through traffic and onto the shoulder. Diagnosed and replaced by Jerry's GMC. They replaced the motor at no charge except I had to provide the new radiator because it was on backorder. They had the truck for over 3 months and I had no loaner vehicle. With approximately 65,000 miles on the latest engine, a lifter went out. I put it in the shop to have all the lifters replaced, and motor mounts replaced at a cost of $6500. Upon taking the truck for a test drive, the engine seized in traffic under an overpass and blocked one lane of traffic. The shop dropped the oil pan to check it out, and, lo and behold, this engine has spun rod bearings again. There is definitely a serious and dangerous problem with the L87 6.2L. Being a 2020, it is not currently included in the recall, but it needs to be included. I spun bearings the first time in August of 2021. I was hoping it was just bad luck. I hadn't heard of all the instances at the time. I've never had a major engine failure prior to this model, and this one has failed 3 times in the same truck with meticulous maintenance.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Inwood, WV

    The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving 55 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, there was an abnormal sound coming from the engine. Multiple warning lights were illuminated. The contact was able to coast to the side of the road. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The engine was repaired. Most recently, while driving 35 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal, with an abnormal sound coming from the engine. Multiple warning lights were illuminated. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The contact was informed that the camshaft, bearings, and lifters in cylinder #4 had failed. The vehicle remained at the dealer unrepaired. The manufacturer was notified of the failure. However, no assistance was provided. The failure mileage was approximately 19,000.

    Source: HOTLINE VEHICLE OWNERS QUESTIONNAIRE
  • 2020 GMC SIERRA 1500
    - Romeo, MI

    The check engine light went off and started blinking. The engine started making ticking noise. I pulled over. The check engine light kept blinking. I had the truck towed to the Chevy Dealership. They found damage to the lifter and camshaft. They had the truck for over 2 weeks. Luckily I purchased the extended warranty. But the repair still cost me 1,200.00 dollars out of pocket. And cost the warranty company over 9,000.00 dollars

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Calumet City, IL

    Tick sound coming from underneath. Also fumes smell. Dealership found it to be the exhaust system. Said the muffler valve is bad. Quoted me $2000 for repair. Never heard of a exhaust system failure in only 5 years. Very unsatisfied with this.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Nashville, TN

    I heard a ticking noise coming from the engine compartment. I took it to the dealership that I purchased the truck from and that have been using consistently for service. I was told that the noise was coming from a lifter on the driver's side of the engine and, on further investigation, it was determined that the camshaft had been damaged. I was told that it could seize up as I was driving and that my safety and those with and around me would be at risk. At 85,000 miles, the engine had failed and would have to be replaced. There was no prior warning or no check engine light and the vehicle has been in for oil changes and all maintenance at the dealership. The new engine cost me $15000 including diagnosis and towing.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Collierville, TN

    I noticed a ticking sound in my 2020 GMC Sierra 1500 SLT 5.3 Liter on 10/15/2025 after it was serviced at an Authorize Buick GMC Dealership on 10/13/2025. I made an appointment and returned the vehicle to the dealership for further inspection on 10/17/2025. I was informed later that day that my truck has lifters and camshaft failure. If my truck had stalled or stopped on the express way, myself and others safety could have been at risk. My truck has only been looked at by the dealership at this time, and it is available for inspection upon request. There were no warning lights, check engine lights, messages or symptoms prior to the failure. I did get a low oil level message in April 2024 when the dealership stated they must not have put the correct amount of oil in my truck during an oil change on 1/29/2024. They inspected my truck and assured me there was no damage done to my Engine from this issue. I have recently learned there is a recall for GM Vehicles manufactured between 2021 and 2024 with the 6.2L engine installed. I am not sure why this recall does not include 2020 trucks with the 5.3L engines installed. Apparently, the same problems exist with these engines also. I received an estimate for repair approximately $13,000 which can increase once the engine is town down and inspected further. Any assistance you can provide would be greatly appreciated.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Wewahitchka, FL

    The engine failed completely while driving. On the day of the incident, I started my 2020 GMC Sierra 1500 AT4, and immediately upon cranking, the engine began knocking loudly. I shut the vehicle off right away to prevent further damage and called a wrecker service to have it towed to Marianna Chevrolet, GMC. No warning lights or messages prior to the incident. The weather was clear and dry, and the truck was parked on level ground at the time. There were no prior warning lights, leaks, or unusual noises before this event. The vehicle has been well-maintained, with oil changes performed regularly every 4,000 miles at a local auto shop (though receipts are not available). The brakes were replaced earlier in 2025. Marianna Chevrolet, GMC inspected the vehicle and estimated the repair cost at $12,700 due to what appears to be a major internal engine failure.

    Source: NHTSA WEB SITE
  • 2020 GMC SIERRA 1500
    - Delray Beach, FL

    The contact owns a 2020 GMC Sierra 1500. The contact stated while driving approximately 40-60 MPH, the transmission hesitated while depressing the accelerator pedal. A dealer was contacted. The vehicle was taken to the dealer and was diagnosed with transmission control module (TCM) failure. The contact was informed that the TCM needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 75,200.

    Source: NHTSA WEB SITE