2021 Chevrolet Trailblazer engine problems

Filed Nov 2, 2026 · Engine, Steering · MI

I am filing this complaint regarding a serious engine failure in my 2021 Chevrolet Trailblazer LS that occurred while I was driving. While driving, the vehicle displayed the warning message “Engine Power Reduced” and I experienced a loss of power steering. Approximately 30 seconds after these warnings and symptoms appeared, the engine failed and I was stranded. The vehicle became inoperable. The sudden loss of engine power and power steering while the vehicle was in motion created an extremely dangerous situation. The vehicle could no longer be safely operated, and I was left stranded after an abrupt failure while driving. This vehicle has experienced recurring engine-related problems since approximately 30,000 miles. Despite previous repair attempts and ongoing concerns, it has now suffered a severe engine failure. The dealership’s diagnostic report states that the engine died and would not crank or start. The technician diagnosed a shredded or failed timing belt that caused the engine to jump timing. The report further documents internal engine damage, including piston-to-valve contact and exhaust-side rocker arms displaced from the valves/lifters. The dealership recommends replacement of the complete engine assembly. The estimated cost to replace the engine is approximately $6,200. I contacted General Motors regarding this failure. GM has offered to contribute only 10% toward the repair cost, leaving me responsible for the overwhelming majority of the expense despite the vehicle’s history of recurring problems. I am concerned that this failure may represent a serious safety defect. Other owners of the same vehicle have reported similar engine-related problems.

Filed Oct 26, 2026 · Engine · 48,000 miles · IL

The contact owned a 2021 Chevrolet Trailblazer. The contact stated that while driving, the vehicle suddenly shut off. The message "Reduce Engine Power" was displayed before the instrument panel went blank. The manufacturer was notified of the failure. The vehicle was towed to several mechanics and the dealer, and the vehicle was diagnosed with timing chain failure. The contact was informed that the engine needed to be replaced. The failure mileage was 48,000.

Filed Sep 7, 2026 · Electrical, Engine · IL

Dear Chevy, I am reaching out to you again because I am desperately requesting immediate assistance with my vehicle, which has now become an extremely serious and dangerous safety concern. On Friday, [XXX], I had my vehicle towed to the dealership because of the ongoing mechanical issues I have been experiencing. I was advised that the repairs would cost $877, which included a battery replacement and new sensors. I paid for these repairs and picked up my vehicle on Wednesday, September 2, 2026, believing that the issues had finally been addressed. Unfortunately, within approximately one hour of leaving the dealership, my check engine light came back on. When I arrived home, the key became stuck in the ignition. I immediately contacted the dealership and requested to speak with a Service Manager. I made this request approximately five separate times, yet I was unable to speak with a Service Manager until Friday, September 4, 2026, when I finally spoke with Matt. The situation has now escalated into an extremely dangerous and potentially life-threatening safety issue. On Sunday, [XXX], while driving on the [XXX] in Chicago, my vehicle completely shut off twice while I was actively driving. There were no warning sounds, no dashboard warning codes, and no indication that the vehicle was about to shut off. My vehicle suddenly lost power while I was on a busy expressway, creating an extremely dangerous situation and nearly causing a major accident/pileup. I genuinely feared for my life. A vehicle that unexpectedly shuts off while traveling at highway speeds is not something I can safely continue driving. After this occurred, I had the vehicle towed to my home. I later attempted to start it, and the vehicle did start; however, the key became stuck in the ignition again. This problem has been ongoing for over a year, and I have repeatedly and desperately asked for these issues to be properly diagnosed and repaired. I have already INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5

Filed Sep 3, 2026 · Engine, Fuel system · MD

Original Owner of 2021 Chevy Trailblazer LT. Purchased new in April 2021. Vehicle has a history of major powertrain issues, starting with Check Engine light during its first year of ownership, culminating in a complete turbocharger replacement in December 2025. This only as a result of my research, after many visits to dealership trying to diagnose the issue. The check engine was consistently illuminated in the vehicle 2021-2025. 9 days ago while traveling the vehicle, experienced sudden oil pressure loss, and stalling risks, displayed a hard warning “ENGINE OIL PRESSURE LOW. STOP ENGINE”. On Star provided me with a diagnostic code of P0521, pointing to an engine oil pressure sensor malfunction. Apparently another widely known issue with this engine, there are TSBs stating after repair the code will return and Software Update required. Extended warranty has expired, dealership as well as GM corporate unwilling to provide any assistance with cost of diag, repairs, etc, leaving myself and disabled dependent stranded. Vehicle since purchase has been exclusively serviced through the purchasing dealerships service center. Maintenance regularly maintained. Service management has admitted knowledge of this issue with this engine, still reluctant to provide any additional assistance, informed me I’m on a waitlist for a possible loaner vehicle 4-6 weeks from now. There are several TSBs on this engine surrounding this issue. Apparently there is a known defect with the engine oil pump, cam shaft, evap purge pump. Strong possibility could be a result of the Turbo replacement, debris from that failing turbo could have blocked the oil system, causing starvation.

Filed Aug 3, 2026 · Engine · IL

My timing belt snapped prematurely, causing a total loss of engine power while driving on the highway, which is a severe safety hazard

Filed Jul 23, 2026 · Engine, Transmission · MO

My trailblazer will not shift properly into drive from park or reverse. GM calls this a "loss of forward motion" or "delayed forward engagement" in their service bulletin TSB-24-NA-009. It is a safety issue because you never know when or how long the vehicle will take to engage and allow forward movement. This causes issues when leaving a parking spot or a driveway, especially on busy roads. If the car will not move forward, my family is stuck in the road until it finally engages into gear and allows forward movement. When this occurs, the vehicle engine will shutter and not allow any forward movement. I usually have to move the drive selector back to park and back to drive again. This creates an immediate and unreasonable safety risk because the vehicle will not move for several seconds while I am sitting in traffic. This generates a P2714 code. I had the car looked at by a GM dealer as well as an independent transmission repair shop and both indicate it will likely need a new transmission. GM is fully aware of the defect and has issued a service bulletin, TSB-24-NA-009 to instruct dealers how to diagnose and repair the problem. The bulletin proves a widespread engineering or manufacturing flaw exists. However, GM is treating this as a maintenance issue rather than the severe safety hazard that it is. It is my understanding, GM has since abandoned this transmission on the newer models, further indicating that GM knew these transmissions were not designed well. I am requesting the federal safety agency office cross-reference my complaint with GM TSB-24-NA-009 and upgrade the component defect to a mandatory, manufacturer-funded safety recall before it causes a collision or fatal injury. Thank You

Filed Jul 18, 2026 · Engine · CA

Reduced engine powers caused by turbo charger underboost, at 91200 miles.

Filed Jul 11, 2026 · Engine · OH

car was driving fine, went up a hill then check engine light came on with warning that stated "reduced engine power." drove it approx 8 min to home. parked in garage. Next morning, took to Firestone Complete Autocare as that was the first place available. Just got a call that the whole turbo assembly needs to be replace costing almost $2000 and will be without a car for about a week. 5 year warranty expired 3 months ago and there is less than 47,000 miles on it. It is currently at the shop so I don't have a bill yet, but they told us how much when they told us what was wrong with it. This is unacceptable! Reading about and hearing about this complaint all over the internet!!!

Filed Apr 17, 2026 · Engine · OH

2021 Chevrolet Trailblazer RS (123,000) - Coolant control Valve failure Cooling issues after 20-25 mins of driving. No Check engine lights initially just temperature gauge climbing. After 3 day of trying to drive to and from work. "Engine reduced" and P3075 code. Had it towed to dealership, in which they replaced the water pump. This DID NOT fix the issue. The next two drives (from work, and to work), I had to pull off the road several times to get the car cooled down, and run heater on full blast to drop temperature. Pulling off the road in heavy interstate traffic consistently because of the Coolant Control Valve (25207464 GM). Not to mention me, looking at the temp gauge most of the way to work, versus eyes on the road. The old thermostats would at least give you a temperature code, and not an Engine Coolant Flow Too Low error which leads to water pump being replaced erroneously. Going to plastic control valve next to a hot engine, sounds as good as plastic car jacks for this car. Oh, wait, that happened to me as well, and they recalled it after it broke on me at 2 am in the morning.

Filed Apr 16, 2026 · Engine · TN

While driving down the interstate my 2021 Chevy Trailblazer suddenly flashed "Battery Saver Mode" on the dash and shut off completely. I was able to coast to the side of the road and call for help. This was a MAJOR safety issue as my 4 year old son was riding with me and we could've caused or gotten into a serious accident. There were no previous warnings and no Check Engine Light came on prior to it shutting off--I had been having no issues. The car will not turn on and when attempting to, it makes a screeching noise. I had to get it towed to a local service center who stated my car has "catastrophic engine failure". They advised the issue could be either "timing chain or a dropped valve"--unable to confirm until they take the engine apart completely. They denied issues with the battery or starter and said the engine was completely blown. There was less than 120k miles on it and i kept up with maintenance.