*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Power train
I own a 2020 GMC sierra AT4. It has developed a shudder when cruising on the highway or driving in town around 1500rpm. I believe it is coming from the transmission. A local shop mentioned the torque converter. The shudder feels like a delay in power and makes it difficult to hold speed or accelerate when needed.
Oct 1, 2026Steering
This morning it seems as if my 6.2L GM motor threw a rod. All the initial sounds and check engine information point toward that. I will be taking it to a dealer to confirm the issue. Data center driving ability and sounds indicate steering was affected as well or is somehow connected.
Oct 23, 2026Unknown or other
Transmission control valve real,rear wheels can lock up causing accident recall # 26V083000
Oct 19, 2026Engine
I was driving and my truck shut down on me while I was driving down the road, I had to get it towed to the dealership where it was confirmed that the motor would need to be replaced. There was no warning, it just turned off and luckily I was able to coast to a safe area to wait for the tow truck.
Oct 2, 2026Engine
[XXX] General Motors Company P.O. Box 33170 Detroit, MI 48232-5170 c/o Franklin, Customer Support Re: Formal Demand for Buyback â 2020 GMC Sierra AT4 Black Widow VIN: [XXX] | 6.2L Engine Recall ~ 25V-274. Plus ~ GM 10-Speed Transmission, Multiple Recalls Dear GMC Legal, I am providing written notice as required by 15 U.S.C. §2310 and New York State Lemon Law. This vehicle substantially impairs the safety, use, and value of my truck, and I am requesting a full buyback. The Facts: On [XXX], the vehicle was taken out of service and remained at the shop for 11 weeks. It was returned with yellow marking paint splattered on the exterior, floor mats, and brake pedal. On [XXX] â with fewer…
Oct 15, 2026Engine
Driving down road started to hear a weird growling knocking sound and noticed a reduction of power. also noticed lower then normal oil pressure. Changed oil found metal shavings in the oil. sent to chevy dealership. Diagnosed "rod bearing failure" needs new engine.
Sep 16, 2026Visibility
The contact owns a 2020 GMC Sierra 1500. The contact noticed an abnormal odor inside the vehicle. Upon inspection, the contact observed that the roof, rear seats, and rear carpet were saturated with water. The vehicle was taken to the dealer, where the contact was informed that the rear sliding window frame connected to the roof was fractured, causing water to leak into the vehicle. The contact was informed that the failure was a factory defect associated with an unknown recall; however, the VIN was not included. The manufacturer was notified of the failure by phone and referred the contact to the dealer. The contact was advised that the repair was not covered because the VIN was not…
Oct 10, 2026 · 90,320 milesEngine and engine cooling
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle suddenly entered Limp mode without warning. The vehicle was taken to the dealer, where the computer was reflashed and the vehicle temporarily returned to normal operation; however, the failure recurred and the vehicle was returned to the dealer. The contact noticed a burnt odor coming from the engine compartment, along with engine bay cooling fans running at an unusual rate. Upon further inspection, the dealer diagnosed the failure as a defective coolant valve. The contact associated the failure with GM Special Coverage TSB N252508341; however, the VIN was not included in the…
Sep 29, 2026 · 107,000 miles
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.