NHTSA Complaint #11432369 — 2021 GMC SIERRA 1500

While driving on the highway my truck started to buck and had a loud engine knocking noise. Speed was greatly reduced so much so that I was going under 45 mph in a posted 65. The check engine light did not come on. While sitting on the side of the highway there was a severe engine knock only when the revs on the engine were increased. Oil pressure and cooling temps were as they should be. The next day on the way to the dealership the engine started knocking. This time the check engine light came on, speed was greatly reduced at this time. After about five miles the knocking stopped and the check engine light went out. The Dealership checked it out and stated the lifters were bad. It seems that this is a known issue with GM. I was told by the Dealership that there were two other trucks ahead of me with the same issue. Also, because this is such a prevalent issue with GM, they cannot keep up with the demand for parts. My Dealership is waiting for a head gasket. GM has known about the faulty parts for approximately two years, and they are only replacing some of the faulty, poorly made parts, hoping the other side of the engine will not develop issues and fail. I feel this is placing the driver and occupants at risk while driving down the highway and not being able to maintain posted speed limits, or just locking up and engine, and coming to an abrupt stop.