NHTSA Complaint #11482905 — 2015 CHEVROLET COLORADO

Beginning in 2018, perhaps earlier, I noticed that often when I would press the accelerator all the way, the engine would (and still does) make a sound (I’ve since learned, through many dealership interactions and internet searches, that the sound is referred as pinging or knocking from pre-detonation), and it SEEMED that the car’s computer would (and still does) electronically back off the throttle, and the rpm’s reduced in terms of speed of acceleration (sometimes the rpm’s even DECREASED as opposed to merely increasing less rapidly). This has placed myself and passengers of the car in danger by causing the car to go through intersections significantly slower than I (as well as my mother who also occasionally drives the car) would naturally anticipate, as this slow crossing through the intersection has led to many close-calls when intersecting traffic (when they have the right-of-way) almost crash into the broad side of the truck. It USED to occur I would put in any fuel with an octane rating lower than 91, but now it even happens with 91 octane fuel. The problem has been reproduced by two Chevrolet dealerships. I have taken it in many times to have them repair/replace/service parts that I thought might be causing the problem. The shop foreman at one location replicated it and said he had no idea what the cause could be. The service dept. was then in back-and-forth contact with engineers at GM over the next couple of days, and the engineers eventually suggested an oil system flush thing (which ended up not helping). It’s had oil filter changes, fuel induction service, and basically everything short of replacing the injectors or pistons. Neither the vehicle nor its components have been inspected by the manufacturer, police, insurance representatives or others. No warning lamps or messages have ever displayed in relation to the problem. My co-worker’s husband has a 2018 GMC Canyon with a V6, and says the exact same thing happens with his car.