2021 Chevrolet Blazer

The transmission (powertrain) developed a delay when shifting into reverse, followed by harsh engagement. The condition worsened over time and resulted in a complete loss of reverse. The vehicle will not move when shifted into reverse. This creates a safety risk when parking, backing out of spaces, or maneuvering in traffic, as the driver cannot safely control vehicle movement. The issue occurred at approximately 89,000 miles under normal driving conditions. No warning lights were present prior to failure. The problem was reported to a dealership and diagnosed as a transmission failure. The condition is reproducible and ongoing. I was also informed that multiple vehicles of the same model were experiencing similar transmission issues at the same time. The failure limits safe operation of the vehicle and increases risk in situations where reverse movement is required.

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the vehicle with several unknown warning lights illuminated. The contact stated that the electronic parking brake independently activated. Additionally, the failure had occurred while the vehicle was parked. The failure was persistent. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 31,000.

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.

Once I turn the vehicle off, there is a loud sound coming from the engine area that sounds like a fan. Then the first incident of the fan ongoing after the vehicle was powered off, a battery light was on the internal driver dashboard and stayed on. The battery was recently replaced during 2026 so the battery should not be anywhere near dead, dying, or needing to be checked

The contact owns a 2021 Chevrolet Blazer. The contact stated that while attempting to start the vehicle, several unknown warning lights illuminated, and other lights inside the vehicle flashed on and off. The contact stated that the failure also occurred while driving at various speeds. A dealer was contacted. The vehicle was taken to several dealers for diagnostic tests; however, the diagnostic result was unknown. The manufacturer was notified of the failure and informed the contact that there would be a callback about the cause of the failure; however, there has been no callback yet. The approximate failure mileage was 50,000.

My 2021 Chevy blazer Lt v6, has a service bulletin extending warranty on thermostat malfunction, that also causes the fans to run after the car is off. My vechicle was experiencing this issue, went into my local dealer, they claim thats not my issue, I need a new radiator, that has never leaked, or the car running hot. Beyond that the radiator has a service bulletin, they can fail, do to poor quality from supplier, some were replaced under warranty, some were not. This vechicle has 47000 miles, I should not be responsible for this issue. Thank you [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Coolant smell when parked with engine running. Radiator was replaced under warranty at 16,000 miles Coolant smell again 49,000 miles. "Pressure tested at dealership with following notes: "Found radiator core on driver side seeping/leaking. provided estimate on cost. no repair made during this visit." Many forums on 2021 Chevrolet Blazer note poor quality in radiators. This would be the 3rd radiator in less than 50,000 miles on the vehicle.

At 48,000 miles, check engine light came on and loud fan sound continued after turning car off. Took car to dealership where I was informed I needed a new radiator and it is not covered by warranty.

This submission is an additional report related to NHTSA complaint #11714381. At approximately 55,000 miles, my 2021 Chevrolet Blazer experienced a sudden throttle body failure while driving. The vehicle entered reduced engine power/limp mode without warning and acceleration was significantly limited. This created a safety concern while driving in traffic, particularly when merging and crossing intersections. Diagnostic code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. Although the repair was completed, this failure occurred at relatively low mileage for a critical engine control component. A sudden loss of acceleration can pose a safety risk depending on traffic conditions. Since filing my original complaint, I have identified multiple similar reports online and in owner forums describing premature throttle body failures in GM vehicles with similar symptoms (reduced power/limp mode and limited acceleration). This suggests the possibility of a broader pattern involving this component. I am submitting this additional report so that NHTSA has a complete record of the incident and potential pattern of premature throttle body failures. If this issue is widespread, it may warrant further review or investigation as it affects vehicle acceleration and safe operation.

The 2021 GMC Blazer (and related Chevy Blazer models) is experiencing recurring radiator failures, often requiring multiple replacements within short timeframes. The radiator was replaced in March 2024 and in early 2025 I went for an oil change and complained of smelling coolant and asked if it could be checked and was told nothing was wrong. I was told again in November 2025 that it has a leak and went to have an oil change in February 7, 2026 and was reminded that the coolant was low and the radiator needs replacing when I was first told I did not believe it to be true as it has been replaced before and I asked that it be checked and was told nothing was wrong.

Around 55,000 miles, my 2021 Chevrolet Blazer experienced a throttle body failure. The check engine light illuminated and the vehicle entered a reduced power/limp mode condition. Throttle response was significantly limited, and the vehicle could not accelerate normally. While the vehicle remained drivable, it took substantially longer to reach speed, which could pose a safety risk when merging into traffic or crossing intersections. Diagnostic trouble code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. This component is a critical engine control system, and failure could affect acceleration and vehicle control, posing a potential safety risk. The failure occurred well before expected service life and required a costly repair. The component has been replaced and is available for inspection upon request. I believe this may represent a premature defect and should be investigated for similar failures in other vehicles.?

Thermostat issues, gives warning steering assist decreased and then eventually check engine light, vehicle thermostat does not react/reach normal temperature, fan continues to blow after car is turned off for 5-15min, AC does not blow cool air or warm if heat turned up

Radiator failure caused power steering assist to not function properly and insufficient vehicle heat function. Engine electric fan would run continuously after vehicle shutdown.