2020 Chevrolet Silverado engine problems

“Incident: Twice our Chevrolet Silverado 2020 Duramax has experienced while operating, sudden with no warning "reduced engine power" and "check engine light" the engine sounds very different and does not operate as it should and presents a safety issue when you are driving and traveling at a high rate of speed. These incidences occurred on 10-4-2026 and 10-23-2026. The vehicle experienced a sudden failure of the engine coolant control valve, triggering Diagnostic Trouble Code P1006. This component failure restricts proper engine thermal management and poses a risk of sudden engine overheating while driving. General Motors has formally acknowledged this identical part failure as a chronic manufacturing and safety defect via Special Coverage Bulletins N252508341 and N252508340, which extend warranty coverage to 15 years/150,000 miles. However, GM has arbitrarily excluded the 2020 model year from this coverage, despite the vehicle utilizing the exact same defective part assembly number as the covered 2021-2023 models. This identical component failure across model years constitutes an unaddressed defect pool that requires immediate regulatory expansion to protect…”

“Had a misfire in cylinder 4 so I took it to the dealership to diagnose. It held compression and switched the plugs and still had the same misfire. They said it was a common issue that the lifters go out with the DFM. It only has about 50k miles on it and I am the original owner”

“I was driving the vehicle at around 50MPH after leaving a set of traffic lights when the engine lost all power and a series of warning lights came on. I pulled over safely to the side of the road and had the vehicle towed to a local vehicle mechanic shop. On investigation the engine had seized and a number of internal components had failed. The engine/vehicle I have owned since new and had approximately 103000 miles on it at the time of the incident.”

“The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that the engine was previously rebuilt. While driving at an undisclosed speed, the vehicle jerked and lost motive power, with several unknown warning lights illuminated. The vehicle was pushed to the side of the road and towed to an independent mechanic, who determined that the engine had low compression, and that the engine and transmission needed to be replaced. The manufacturer was notified of the failure by phone. The failure mileage was approximately 140,000.”

“The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while driving, the vehicle was shuddering. The vehicle was taken to the dealer and was diagnosed with transmission failure. The contact was informed that the torque converter and transmission needed to be flushed. While driving approximately 30 MPH, the vehicle was shuddering and the transmission seized, with the check engine warning light illuminated. The failure had occurred briefly, and the failure was self-corrected, and the contact continued driving. The failure reoccurred approximately 2 - 3 times. The vehicle was returned to the dealer, and the transmission was replaced. The failure persisted, and the vehicle was returned to the dealer, and the transmission was replaced a second time. The vehicle was returned to the dealer, who was unable to diagnose or repair the vehicle. The contact drove the vehicle an additional 20,000 miles before the vehicle received additional repairs. The manufacturer was informed of the issue several times. The failure mileage was approximately 73,000.”

“The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while driving 65 MPH, the engine lifters failed to operate as intended. Additionally, the lifters were replaced three years prior to the failure reoccurring. The dealer was contacted and the vehicle was diagnosed with lifter failure. The manufacturer was contacted by phone and made aware of the failure. The failure mileage was approximately 120,000.”