2021 Chevrolet Blazer: engine overheating

Filed Sep 16, 2026 · Engine, Wheels · MI

My 2021 Chevrolet Blazer has experienced repeated problems involving the cooling system and is now exhibiting recurring symptoms that concern me about the vehicle’s reliability and safety. In 2023, the vehicle required a radiator/cooling-system repair. In 2024, it again required radiator/cooling-system repair, which was performed under warranty. The vehicle is now experiencing an abnormal humming/clicking noise from under the hood. The problem initially occurred primarily after rain but has become increasingly frequent. When the noise occurs, the air-conditioning system stops cooling properly and blows warm air. The check-engine light has also illuminated intermittently. The exact component currently malfunctioning is unknown. The vehicle remains available for inspection. Because the symptoms involve the engine compartment and follow multiple previous cooling-system repairs, I am concerned about the possibility of overheating, loss of proper cooling-system operation, an unexpected breakdown while driving, or another mechanical failure that could place the occupants or other motorists at risk. Authorized Chevrolet dealerships previously inspected and repaired the vehicle’s cooling system in 2023 and again in 2024. Despite those repairs, significant symptoms have returned. The current problem has not yet been definitively diagnosed, so I cannot state that the present failure is the same component previously repaired. The warning symptoms include the abnormal under-hood humming/clicking, loss of cold air from the air-conditioning system when the condition occurs, and an intermittent check-engine light. The symptoms have become more frequent over time. I am reporting this because of the recurring nature of the problem and the vehicle’s history of multiple cooling-system repairs. I request that the federal safety agency document and evaluate this complaint together with any similar complaints involving this model and model year.

Filed Dec 7, 2025 · Engine, Transmission · MI

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 the federal safety agency investigate this issue, as it appears to affect many owners and poses a significant safety risk.

Filed Nov 24, 2025 · Engine, Steering · IL

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

Filed Oct 9, 2025 · Electrical, Steering · MI

Request for Recall Review – 2021 Chevrolet Blazer Steering Assist and Cooling Fan Issue Hello, I am writing to report a recurring issue with my 2021 Chevrolet Blazer and to request that this concern be reviewed for possible recall or warranty coverage. The vehicle frequently displays an “Action Required: Steering Assist is Reduced. Drive with Care” message while driving. Additionally, after shutting off the vehicle, the engine cooling fan continues to run for up to 20 minutes, as if the vehicle is overheating. This issue has occurred multiple times and raises concerns about potential problems with the steering assist system, cooling system, or electrical sensors. I’ve noticed that other Blazer owners have reported similar experiences online, which suggests this could be a broader issue. Could you please confirm whether there are any existing recalls, technical service bulletins (TSBs), or warranty programs addressing this condition? I would also appreciate guidance on the next steps for inspection or documentation. Vehicle Information: Year/Model: 2021 Chevrolet Blazer

Filed Apr 28, 2025 · Engine · PA

Took 2021 Chevy Blazer to a Chevy dealer for small leak. 25000 miles and dealer said I have a leak in the radiator and needs to be replaced. If I didn't notice the small leak the engine could overheat, and possibly start a fire.

Filed Mar 5, 2025 · Engine · 95,000 miles · TX

The contact owns a 2021 Chevrolet Blazer. The contact stated that upon turning off the vehicle, the fan remained engaged for approximately 10 minutes. Additionally, the contact stated that the A/C system was intermittently inoperable. The contact stated while driving at an undisclosed speed, the vehicle made an abnormal sound, and the contact noticed that there was a coolant leak onto the floor of the vehicle. An unknown warning light was illuminated. The vehicle was taken to East Houston Auto Electric, where it was diagnosed that the thermostat was stuck and needed to be replaced. The vehicle was not repaired. The dealer and the manufacturer were not notified of the failure. The failure mileage was approximately 95,000.

Filed Oct 17, 2024 · Engine · MO

The Radiator has a crack in the upper left front of the core causing the fluid to leak and lose pressure causing the engine to overheat. This is a manufacture defect that has not been addressed as of 10/16/2024. The leak was discovered by a certified GM mechanic at a dealership when doing routine maintenance and inspection. The vehicle has never had any indication or advisory light that would alert the operator. As the engine overheats it can cause many of the other components of the vehicle to disable, including but not limited to the ADAS systems as well as power steering and/or collision safety components. This is a manufactures defect with the aluminum radiator that needs to be addressed immediately. Given the information from multiple GM dealerships the amount of newer low mileage Blazers that have been confronted with this problem is unprecedented. This not only creates a danger for the passengers of the vehicle but also every other vehicle on the road.

Filed May 3, 2024 · Engine · MI

I have a 2021 Chevy Blazer which has had to have two radiators replaced with less than 50,000 miles on the vehicle. The first time was in March of 2023. I took my vehicle in for an oil change and the technician told me the radiator was cracked and all of the coolant was drained from the vehicle. It must have just run out because I regularly check my fluids and the vehicle was not overheating prior to the appointment. The vehicle had about 32k miles on it, so the radiator was covered under warranty. Now in April of 2024 with 49k miles, I take my vehicle in for another oil change and the radiator is cracked, again, with coolant leaking. The technician told me two things that are concerning about this. 1.) This is a known issue on the Blazers that they’ve done multiple repairs on. 2.) There is a piece of plastic under the radiator that catches the coolant when it leaks, making it hard to notice an issue because the coolant doesn’t pool on the ground underneath. My service advisor went to bat for me against GM, who partially paid for the second radiator. This brought my installation cost to $235, even though it was no longer under warranty. Radiators cracking is a serious safety issue because if the driver doesn’t notice the engine overheating, it could cause a vehicle fire putting the occupants and surrounding environment in danger. There are no warning lights on the vehicle to tell you if there is low coolant, other than noticing the temperature gauge when it is too late. I don’t know if GM didn’t install rubber bushings to absorb the impact of bumps on the road, or if it needs some rubber washers on the bolts, but something is missing. Online forums will confirm that this is an ongoing issue for owners of the Chevy Blazer