2021 Chevrolet Blazer

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.

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.?

For about a week and a half my car had made a high pitched wheezing/hubbing sound when started cold. This occurred at all temperatures cold and warm. Yesterday December 13th I went to run some errands and about a mile into my drive my 2021 3lt 3.6 V6 Chevrolet Blazer lost the ability to power itself. There was no electrical problem however the power train lost power all gears drive and reverse. I was able to get off the roadway without incident. I scan my check engine light and had several check engine lights including a P 0796.

My 2021 Chevrolet Blazer experienced a radiator failure at approximately 42,000 miles. The radiator and cooling system malfunctioned, causing coolant loss and triggering a warning light on the instrument panel. The failed radiator is available for inspection upon request. This defect put my safety and the safety of others at risk because a compromised radiator can lead to engine overheating, sudden loss of power, or even steering assist reduction while driving. These conditions increase the likelihood of an accident, particularly at highway speeds. The problem was confirmed by my Chevrolet dealer, who diagnosed the radiator as needing replacement. They initially quoted $1,800, later reducing the cost to $915.90 after acknowledging that approximately 20 customers per month at their dealership alone are experiencing the same issue. This indicates the defect is widespread, at least regionally, and may be systemic across the model. The vehicle has been inspected by the dealer service department, which is an authorized GM representative. No police or insurance inspection has occurred. Prior to the failure, a warning lamp illuminated on the instrument panel, alerting me to a cooling system issue. This was the first symptom I noticed before bringing the vehicle in for service. I believe this premature radiator failure represents a systemic defect in the 2021 Chevrolet Blazer’s cooling system. It occurred well within the 5‑year/60,000‑mile warranty period, yet the dealer claimed the radiator is not covered. I am requesting NHTSA investigate this issue, as it appears to affect many owners and poses a significant safety risk.

In September 2023, when getting my vehicle serviced for a routine oil change, I was told there was a leak in my radiator. They replaced the entire thing under warranty. On November 15th, 2025, while driving on the highway heading home from out of town with my children, an error flashed up saying “steering assist is reduced – drive with care” Upon arriving home, the fan on my car was running on high for a solid 10 minutes after turning the car off. No recall but Special Coverage N252508350 covers the thermostat replacement. Upon inspection by a mechanic, I was informed that the radiator is also leaking again in the exact same spot as it was previously. It should be noted I have never seen leaking fluid in my garage/driveway. I’ve driven less than 10,000 miles since the radiator was replaced previously. If there is a known problem with the coolant system which can cause overheating and steering assist issues, why isn't the faulty radiator and thermostat recalled. The radiator is cased in plastic to aluminum. Plastic can easily catch fire if a car overheats. The casing also prevents an owner from even knowing if there is a leak since the plastic is catching leaks - the mechanic informed me that's why I didn't know about both times it leaked. This is a 4yr old car with 46k miles, twice replaced radiator and thermostat. A recall should be issued since both problems could potentially cause a fire from an overheated engine & loss of steering assist while driving. A google search quickly showed me thousands of other Chevy Blazers from 2019-2021 with reoccurring thermostat and radiator issues. I feel unsafe driving in my vehicle but still owe too much to even trade it in for something else. I've owned dozens of vehicles in my lifetime, used and new and keep them 8-10yrs and have never had to replace a thermostat and radiator. This vehicle is dangerous due to GM/Chevy's cheap radiator model and thermostat which could overheat and catch fire

Car was running fine yesterday, today does not want to start. Thought it was the battery, bought anew battery. Still wouldn't start. Rest of cat is getting great power. Code reader is reading its a fuel pump control moduler which just so happens to be in an open recall for my exact year of vehicle yet my vin number does not pop up on the GMC website under active recall. I have a 2021 chevy blazer .

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.