2020 GMC Sierra 1500 engine problems

231 owner complaints filed with NHTSA name the engine on the 2020 GMC Sierra 1500 — 50% of all complaints for this model year.

231

Engine complaints

50%

share of all complaints

48,000 mi

median reported incident mileage

3 / 1

crash / fire reports

What owners report

“5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake…”
filed Sep 15, 2026
“Powertrain issues and a chassis issue that is extremely dangerous.Tailgate on rare occasions falls open by itself. There is a design flaw in the placement of the catalytic converters. The heat is burning up the fluid. I could not believe my eyes when I serviced the transmission. This is another…”
filed Sep 9, 2026
“I was driving home with my wife. The engine just cut off. No power to the gas pedal. Luckily we were able to coast long enough to find a shoulder to pull off onto. Truck wouldn’t restart. Had to call a tow truck and have it towed to the Chevy dealership. The engine was already repaired once. Ref number 11696129. I…”
filed Sep 9, 2026

Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.