Chevrolet Blazer engine failure problems

Filed Nov 4, 2026 · Engine, Transmission · GA

On [XXX], my 2021 Chevy Blazer broke down in the middle of traffic in a left turn lane when it tried to auto-restart. I was left stranded for 2 hours and had to call the local police to direct traffic around me. Upon towing to a local auto shop, and then another two to Carl Black GMC in Roswell, Georgia, I learned that the engine had completely seized due to a leaking radiator. They quoted me $14,000 in repairs between the radiator and a new engine. The vehicle had approximately 84,000 miles at the time and GM offered $3,000 to help with the engine. The car never threw a check engine light prior to the engine completely seizing. The coolant temperature gauge in the car also never showed temperatures above normal. At a few points, the car fan ran loud after turning the car off and I thought this might have been electrical. I sanded and cleaned the ground connection to the chassis which seemed to fix the issue. I also learned of Special Coverage N252508350-Engine Coolant Thermostat that was issued by GM which indicated this condition could be caused by a coolant engine thermostat that could open at a low temperature. I had planned to get it completed along with the fuel pump control module recall at my next opportunity. This issue with my car left my stranded in the middle of a busy highway with cars zooming around me. GM has known about the issue of leaking radiators in 2021 Chevrolet Blazers for years and has never done anything about it. Between their shoddy electrical systems and the radiator, these cars are of significant risk of seizing up in the middle of traffic with no warning like mine. GM has refused to replace these radiators or issue a recall becaus the repair is $2,000 and affects multiple lines of vehicles.

Filed Sep 17, 2026 · Brakes, Engine · WI

Vehicle Information: 2021 Chevrolet Blazer 2.5L engine, VIN [XXX]. Odometer 118000 miles.Description of Incident: While operating the vehicle, the mechanical brake vacuum pump experienced a catastrophic internal failure. The drive gear housing shattered violently without warning, shearing off the end of the connecting engine camshaft. Because this was an instantaneous mechanical failure, the vehicles computer did not trigger any dashboard warning lights, check engine lights, or safe mode protocols prior to the failure.Safety Hazards and Component Damage: First, the total destruction of the vacuum pump caused an immediate compromise to the brake booster vacuum lines, resulting in a sudden, dangerous loss of power braking assistance. Second, the sheared camshaft breached the engine valve cover or head, causing the engines pressurized oil system to instantly dump all engine oil externally onto the ground. Third, shrapnel or violent structural torque from the instant engine seizure punctured or severed the adjacent transmission cooler fluid lines and compromised brake fluid lines, causing total loss of transmission fluid and brake fluid simultaneously.Request for Action: This failure mirrors the exact mechanical defects documented in GM Technical Service Bulletin 21-NA-268 and previous GM vacuum pump recalls like the federal safety agency Recall 19V‑645, which excluded the 2021 Blazer. I am filing this report because the lack of an electronic warning indicator before a catastrophic mechanical brake and engine failure poses an extreme, immediate threat to highway safety. GM must expand recall coverage or issue a Special Coverage Adjustment for this model year. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 24, 2026 · Engine · MI

My 2021 Chevrolet Blazer RS equipped with the 3.6L LGX V6 experienced catastrophic engine failure at approximately 90,200 miles. The vehicle had no prior warning. The dealer diagnosed the timing chain / lift/ cam damage. I am requesting investigation into whether this represents a safety or durability defect affecting other vehicles

Filed Aug 21, 2026 · Engine · MI

While idling in my driveway, the engine started to shake and the check engine light came on. Got it diagnosed and was told by a private repair center that we had lost compression in cylinder 4 and that it was not worth the repair and we needed to replace the engine. Got it towed to the dealership, Bill Fox Chevrolet, for a 2nd opinion and they confirmed what the private shop had said. Because the vehicle was well maintained with regular preventative maintenance, it was deemed the failure was not the fault of the owner. GM extended a goodwill warranty to help cover the cost of the engine replacement (70% coverage. We were 1 month and 2,000 miles past our warranty). They never told us root cause, only that it would have cost more money to repair it than it would be to get a new engine. The Blazer had been running fine up to that point and was my wife's main mode of transportation. The Blazer only had 62,000 miles on it when the failure occured.

Filed Apr 29, 2026 · Brakes, Engine · ID

Went to park car in a park to drop daughter off and it sputtered out and stalled out of nowhere with no warning. I had received a lamp warning very sporadically prior to this and on occasion that stated 'reduced steering assist drive with care' this resulted in heavy steering for that drive until car was shut off and then it would go away and be fine again, fixed the car through Knudtsen Chevy due to a recall about a month before on the issue with the engine being turned off and it thinking it was still hot and still running the fan (even though the car was not running). Knudtsen fixed that issue. Low battery voltage light did not come on however battery was older so had battery installed at park to ensure the issue was not due to the battery. The oil was fresh and showed no issues, changed 2 weeks before fresh oil no issues found during service. When tried to restart the car it would think it would try to start and then sputter out and not stay in idle. Les Schwab left and called a mobile mechanic to bring the computer. Computer was hooked up and it would try to start, however, it would not know it was already running and try to start again on it's own...the codes that came up were the PO101 code came up for Mass Air Flow issue...and then the codes would go in a wild sequence of fail.....mechanic checked for loose connections around air filter, took air filter out and it was clean no issues, checked pipe no visible issues. We walked away and walked around the park to give it some time to sit and then we tried it again and it tried and sputtered out and died again would not stay idling. Then all of a sudden we heard it try to start itself without us trying to start it and it clanked. We hauled it to Knudtsen for a diagnosis. They stated "the motor will not turn this way or that way and it is seized or locked up". This is a 2021 with only 89,000 miles it should have a longer life than this. Please investigate and is there anything we can do to fix it?

Filed Apr 29, 2026 · Engine, Fuel system · SC

Re: Vehicle Safety Defect Complaint – 2023 Chevrolet Blazer To Whom It May Concern, I am submitting a formal safety defect complaint regarding my 2023 Chevrolet Blazer. This vehicle has exhibited multiple system failures that present a serious risk to driver safety and public roadway safety. The vehicle was purchased new on July 20, 2023. Beginning on April 21, 2025, at approximately 27,610 miles, the vehicle developed a progressive defect initially presenting as oil-related issues. Despite multiple repair attempts, the condition worsened and required a full engine replacement in January 2026. Following the engine replacement, the vehicle continued to experience critical safety failures, including engine stalling, reduced engine power warnings, and electronic stability control (ESC) alerts. On April 26, 2026, the vehicle experienced a driver assistance system malfunction in which it attempted to steer off the roadway. I was forced to manually disable the system to maintain control of the vehicle. On April 27, 2026, the vehicle exhibited a fuel system failure, including fuel leakage and fuel odor, along with multiple simultaneous warning indicators: • Reduced Engine Power • Service ESC • Steering Assist Reduced / Drive with Care • Power assist driver system disabled This combination of failures presents both a fire hazard and a loss-of-control risk. Additionally, I was informed by the dealership that a high-pressure fuel line, a one-time-use component, was not replaced during the engine installation. This raises concerns regarding improper repair and continued unsafe operation of the vehicle. The vehicle has undergone multiple repair attempts and a major powertrain replacement, yet continues to present serious safety concerns. Due to these ongoing issues, I do not feel safe operating this vehicle. I respectfully request that the federal safety agency review this matter for potential safety defects that may impact other vehicles of the same make and model.

Filed Apr 16, 2026 · Engine · CA

The vehicle had an oil leak from both the left and right camshaft carriers. The dealer confirmed the issue and carried out the necessary repairs. Because the leak was not easily detectable, it could have led to engine failure while driving. There were no warning indicators; only small oil droplets were found on the ground.

Filed Feb 18, 2026 · Engine, Transmission · 70,000 miles · TX

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with VVT sensor failure. The sensors were replaced; however, the failure recurred. The vehicle was taken back to the mechanic, where a solenoid was replaced. The vehicle was repaired. The contact was informed that if the failure recurred, there might be an internal engine failure. The dealer was not contacted. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 70,000.

Filed Jan 28, 2026 · Engine · CA

The engine started acting weird in traffic going down hill on freeway. Eventually turned off turning into my driveway. No warning or engine light. Towed to dealer and is in for inspection, not sure if they can repair or if they have to replace the engine. When it arrived to dealer the engine light was on with a couple misfires

Filed Nov 3, 2025 · Electrical, Engine · MI

Action Required "Steering Assist Warning" drive with caution, Temp gage reads cold, A/C stops working, engine cooling fan runs on high speed (even after the engine is shut off), pending P2018 code, with no Check Engine Light (CEL). Replaced Engine coolant Temperature (ECT) sensor, problem did not go away. Several reviews suggest to replace the thermostat, check fuses for proper insertion, reroute ECT wiring, and possibly replace radiator. Most of these repairs can be very expensive. Chevy Blazer Forum states that the issue is a out of range detection of ECT sensor reading. GM needs to determine a true solution and stop guessing at owner expense/frustration.