2018 Chevrolet Colorado

While driving at normal and safe highway speeds, without warning (no audible or visual warning from the vehicle information display) my vehicle experienced engine lockout, loss of all non-electric power, and no control over vehicle speed. A few seconds after loss, the information display did show a "check engine light" and that the engine was in "lockout." We (my spouse, young child, and self) were surrounded by multiple commercial semi-trucks and passenger vehicles and had to weave and serve to avoid collisions at highway speeds and get to the shoulder of the highway in a few seconds. The root cause as diagnosed by a Chevrolet Dealership Service Department was failure of the magnetic strip that is press fit to the reluctor (tone) wheel. A 1/2in piece of the magnetic strip was missing and over 10 cracks within the strip itself observed. This magnetic strip is used by the Engine Control Module to measure engine RPMs. The strip's failure caused the EMC to shutdown the engine without warning which is a significant hazard for controlled vehicle movement at highway speeds. My vehicle's engine (LWN) is one of the few GM designs that have the press fit magnetic strip reluctor wheels. The rest use integrated wheels with the crankshaft or traditionally stamped steel with machined teeth. The vehicle and reluctor wheel has not been inspected by GM or any other representatives. I offered to send images to GM for records but they declined.

I purchased the truck at the end of March 2025. Within a few weeks I was noticing different issues in the transmission. It would occasionally shudder, have jerky or long shifts, would jump gears and lose power. The shudder was random but mostly on the highway, the jerky or long shifts would mostly occur when the egjne was cold and more often in cold weather. The lose of power and jumping gears would occur when towing and when I was in the mountains, once losing power as I was turning onto a major highway. I took the truck in three times to get diagnosed but they couldnt replicate the issue or find a code. I finally decided to pay for a flush with the fluid that was recommended by a TSB. After the flush the issues were then replicated by the service techs. I have an extended warranty. The representative then inspected the truck and found the same issues and approved a transmission replacement. I took the truck in on June 22nd 2026. As of July 21 the dealership is still waiting for the replacement transmission to be shipped from GM.

Engine fails it violenty thumps and studders and drops from highway speed with no warning. This is a mfg. defect and also an EXTREME SAFETY CONCERN. The engine studders and thumps and we were almost rear ended by a truck when our truck could not go into gear properly. It is very scary! Dealership confirmed that they have many vehicles with same issue and recommended a Super Flush of transmission but not sure this will correct problem or cause more problems. There is no warning when these incidents occur and the driver has no control to avoid it. It is commonly referred to as the Chevy thump and studder and a known mfg defect in which GM refuses to pay for repairs causing consumers an extreme hardship! This is an ongoing issue affecting thousands of vehicles and someone is going to die! There is no negligence of operator of vehicle, it is a manufacturing defect that affects thousands of GM vehicles and they are doing NOTHING about it except expecting customers to keep incurring cost to try to remedy a repair at our own expense which is unfair! The government needs to force a recall at GM's expense!

Highlighting a materials defect with the rear crankshaft reluctor ring on the 2.8 LWN Duramax, installed in the Army Infantry Squad Vehicle and the 2015-2023 Chevrolet Colorado, from which it is based. When the ring delaminates, due to age, the vehicle engine shuts off and no start, rendered dead lined, as the ECU can no longer "see" the crank position. Requiring the transmission to be removed to rectify the issue.  I was pulling a trailer up a hill on the freeway when my truck down shifted, in an effort to slow down for a bus that was merging unexpectedly and the truck died at speed. The increase in RPM initiated an unplanned, instant disassembly of the ring due to cracking on the material and increased centrifugal force, shutting off the engine without warning, at speed. Again, just dead stick to the shoulder, towing a trailer, on the freeway. That could have been bad... Had truck towed to GM dealer, for a month-long repair.

Clunking sound coming from rear end upon normal acceleration. When I take my foot off of the brake pedal, and depress the gas pedal, A loud clunk appears to come from the differential. If I coast first and then depress the gas pedal, it is not as pronounced. When you slow down to make a corner, and resume speed exiting the corner it is also pronounced. It should be noted that I am a safe adult driver (safe driver module installed in truck) and have 35,800 miles. My truck has always been serviced by my Chevrolet dealership; I am an older gentlemen and never drive recklessly. I'd like to think the rear differential should not be making a clunking sound at this point in its history