2021 Chevrolet Blazer

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.

NHTSA ID

11775638

Incident

Oct 29, 2026

In February 2023 we noticed coolant on our garage floor. Car was taken to GM dealership was told radiator seams were leaking. Replaced radiator February 14th 2023 and car had 14,597 miles cost covered by GM warranty. On October 8, 2026 vehicle taken to second GM dealership for driver assist not working be careful. The cooling fan loud when car was turned off. Dealership told us the radiator was again leaking on the seams and will need third radiator (original plus two replacements). The car had 44,328 miles. Cost quoted was $2,125 plus tax and fees. Called GM service line and filed a complaint. They told me car is out of warranty and to ask dealership to give me a payment plan and/or reduce the price. After multiple calls to dealership they said they would give me a 15 percent discount as I am a loyal customer. My wife drives this car and transport two children almost daily. Worried we will lose drive assist when in use possible causing potential issues or accident.

NHTSA ID

11773173

Incident

Oct 8, 2026

Torque converters are going out and causing people to need new transmissions. I was told by dealership that evaluated mine this is a known problem! I’ve also encountered others who have same issue with their cars.

NHTSA ID

11772869

Incident

Aug 8, 2026

My wife and I were just driving and suddenly the motor started stopping installing. We managed to get over toward the curb and shut the motor off and restart it. Then it ran normal. When it did stall out, and we made it to the curb, it shut itself off. That was yesterday then this morning it started to do it a little bit when we left the house.

NHTSA ID

11771904

Incident

Oct 17, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at 35 MPH, a loud cracking sound was heard and there was gray coming from underneath the hood. The contact parked the vehicle. Additionally, the steering wheel failed to turn in the intended direction. Upon opening the hood, the contact noticed gray smoke under the hood. The contact's minor child was occupying the vehicle during the failure. The vehicle was taken to an independent mechanic, where the contact was informed that the AC compressor had melted, requiring replacement of the AC kit and expansion valves. The vehicle was repaired; however, the failure recurred and the ESC warning light illuminated on the instrument panel. The contact stated that the vehicle was unsafe to drive. The contact associated the failure with an unknown recall; however, the VIN was not included in the recall. The failure mileage was unknown.

NHTSA ID

11771320

Incident

Sep 27, 2026

Steering assist reduced light came on, fan kept running after shutting off, brought to dealer to see if it was covered under the gm special coverage for thermostat, they say the radiator needs to be replaced for a leak. I looked it was leaking a bit on the top driverside corner, not actively leaking but a bit of corrosion where it had. So they want to replace the thermostat(covered under gm special coverage), the fan and radiator also replaced. From what I have read online this is a known issue with these radiators leaking at the seams. People end up replacing the radiator multiple times and still leaks. How can they get away with selling these cars with junk radiators and not recalling.

NHTSA ID

11770208

Incident

Oct 9, 2026

The main instrument cluster where the speedometer and fuel gauge etc etc reside went blank during operation of the vehicle. I wasn't able to pull over safely until my destination was reached. Restarting the car seemed to "solve" the issue.

NHTSA ID

11768271

Incident

Jun 17, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed and making a turn, the vehicle lost braking functionality. The brake pedal was depressed to the floorboard. After exiting the vehicle, the contact became aware of a fluid leak underneath the vehicle. The "BRAKE Failure" warning light was illuminated. The manufacturer was notified of the failure. The vehicle was taken to a local dealer, where technicians diagnosed a fluid leak from the vacuum pump, causing the brake failure. The contact referenced NHTSA Campaign Number: 19V645000 (Service Brakes, Hydraulic) as a possible cause for the failure. However, the VIN was not included in the recall. The dealer replaced the vacuum pump, and the vehicle was repaired. The failure mileage was 120,000.

NHTSA ID

11768040

Incident

Sep 28, 2026

Mileage

120,000 mi

This Preliminary Information communication provides information to the technician about vehicles that have an intermittent no crank, no start, or start stall concern with the security light coming on. Technician may find Diagnostic Trouble Codes B3055, B3

• Improvements to OnStar functionality.

This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

PI to help diagnose A/C concern