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2021 Chevrolet Blazer engine complaints

Page 2 of 3: complaints 11 to 40 of 46, newest first, as owners wrote them.

See the summary of 2021 Chevrolet Blazer engine problems: which part fails, at what mileage and related recalls.

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 28, 2026 · Engine · CA

Both camshaft carriers failed due to a manufacturing defect. According to the federal safety agency bulletins 21-NA-240 and PIP5755, the oil leak from the cam carrier is caused by improper sealant application during manufacturing. Although the dealer addressed the issue, it was clearly not a problem that arose from normal use. The leak had the potential to worsen and lead to a fire hazard. Chevy of Montebello confirmed the issue and repaired the vehicle for over $7,500. There were no warning signs, as the leak was difficult to detect on the driveway. The low-oil warning light came on the day before we took the vehicle to the dealer.

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 Apr 12, 2026 · Electrical, Engine · WI

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

Filed Mar 12, 2026 · Engine · MI

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.

Filed Feb 19, 2026 · Electrical, Engine · CA

This submission is an additional report related to the federal safety agency 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 the federal safety agency 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.

Filed Feb 9, 2026 · Engine · OH

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.

Filed Jan 30, 2026 · Electrical, Engine · CA

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.?

Filed Dec 29, 2025 · Engine · MI

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

Filed Dec 15, 2025 · Acceleration, Engine · WA

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.

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 Nov 16, 2025 · Electrical, Engine · NC

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 .

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.

Filed Sep 25, 2025 · Engine · MI

Radiator leak, leaking antifreeze

Filed Sep 19, 2025 · Engine · WI

Was informed at today's oil change that my radiator is leaking and it's something that they are seeing a bunch.

Filed Aug 6, 2025 · Engine · KS

At routine oil change dealer noticed radiator was leaking. 60,840 miles Took it to an independent repair shop who confirmed radiator needed to be replaced. Has also seen same on other 2021 Blazers. No visible signs of leaking (fluid on garage floor) or warning indicators. No recall issued on this, however, seems to be a common problem on 2021 Blazer based on Chevy forums. Due to safety issues, vehicle is currently in shop for the needed replacement repair.

Filed Jul 21, 2025 · Driver assistance, Engine · CA

The first incident started on 08/16/2024, 2 days after buying the vehicle used from Dealership. I started getting notifications stating "Service-Front Camera not available" and sure enough, I no longer had a front camera, which then means I no longer have front collision alerts. Then I started getting the random notifications to drive carefully because drivers assistance has been reduced, and now my vehicle's fan will randomly run for up to 30 minutes after it has been shut off and even after a less than 2 mile drive to gas station and back home, it does this. Last item is the vehicle pulls to the right, and I have not hit anything nor has it ever been in an accident prior to my purchase, and my brakes squeal horribly, which shouldn't be happening condidering I haven't even driven the vehicle 5,000 miles in the year since I bought it !

Filed Jun 17, 2025 · Brakes, Engine · CA

I am reporting a serious safety concern involving my 2021 Chevrolet Blazer, which experienced brake failure while driving, without any warning lights or diagnostic alerts from the vehicle’s onboard system. This created a highly dangerous situation for myself and others on the road. Prior to this incident, I brought the vehicle to the dealership after consistently hearing squealing or screeching noises when braking. The issue was dismissed and attributed to a change in federal regulations limiting the use of copper in brake pads—without any further inspection. This resulted in a missed opportunity to diagnose what appears to be a deeper mechanical failure. After the brake failure, service technicians discovered that the vacuum pump had failed, which impacted braking performance and also caused engine damage. While I’ve since learned that GM has acknowledged vacuum pump failures in several vehicles manufactured between 2014–2018 (via formal recalls), the 2021 Chevy Blazer is not currently included in those campaigns However, the symptoms and outcome I experienced are strikingly similar to the documented defects in older GM models. The lack of early diagnostic detection, coupled with dealership dismissal of clear warning signs, signals a potential emerging safety defect in this newer model that may not yet be officially recognized. Given the safety-critical nature of the braking system and the failure of both mechanical and procedural safeguards, I strongly urge the federal safety agency to investigate whether this issue is more widespread in recent GM models, including the 2021 Blazer. Other consumers may be at risk without knowing it.

Filed Jun 16, 2025 · Electrical, Engine · IN

On the way to work my car said “driver assist is stopping drive with care” about 2-3 times. Upon getting out of my car it sounded like my car was still running. I turned it off and on a few times and it still sounded that way. I had to go inside or I would be late so about 20 minutes later I was able to come back and check on it and the noise stopped. It was coming from the hood. Upon googling I figured it was something to do with a faulty temperature gauge which correlated with the signal from the car as well as the sounds. It seemed like this is a very common occurrence for these cars. I called the dealership and they said they fix these everyday and the man knew exactly what was wrong before I could even finish describing it. Unfortunately I don’t know the cost of this and have already had several other things to repair in my home recently so this will be detrimental to my finances if this isn’t covered. On the way home it did it again along with no AC in the 90 degree heat and then the engine light came on. We had to open the hood and leave the garage door open to prevent any possible harm that may do in the garage. This could be very dangerous for me as I drive my car everyday to work and can’t afford to rent a car for several weeks while this one isn’t working. And I’ve only had it for 6 months. Now my husband and I have ti figure out how we are each getting to work with one car until we get this fixed or we borrow a family members car.

Filed May 3, 2025 · Electrical, Engine · TX

The steering assist stopped working. The defrost stopped working because the ac stopped working. The temp gauge stopped working. Error code P0128. I have since found out all this is caused by a faulty temp sensor.

Filed May 3, 2025 · Driver assistance, Engine · CT

"Driver Assisted Reduced Use Drive With Care Message" comes on when it is over 70 degrees outside. The temperature gage reads zero, A/C does not work, when the car is turned off the fan runs on high for an extended period of time. Showing code P0128 Used car purchase, came on 3 days after receiving vehicle from the dealership. Reset the code came on again 2.5 weeks later (5/3/2025) when the outside temperature was in the 70's

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 Jan 18, 2025 · Electrical, Engine · TX

This is re: dash warning that came on saying "Action Required, Steering Assist is Reduced, Drive with Care" on 2021 Chevy Blazer, 28.800 miles. First happened 1/15/25 & each time car is started it is on now, plus the Check Engine light is on now. The fan of the motor runs for 5-10 minutes once car is shut off also. I have read of the power steering locking totally up on other Blazers that this has happened on, making this a very big danger and risky. I am not sure if it is power steering, electrical, or engine issue, but believe with so many reports out there and it causing a danger to people driving, GM/Chevrolet should put a recall on this and look at these before people are killed (if not already due to this). I am taking mine to Chevy dealer to have it looked at, but many people may not have that option.

Filed Dec 19, 2024 · Engine, Fuel system · WA

On [XXX], I was driving my Blazer up to our local Museum to grab some information. The Museum is about a mile and a half from my house. When I had left my house, the car was driving like normal. I pulled into a parking spot at the Museum, and I went to shut the vehicle off, and I thought maybe the check engine light had come on but wasn't completely paying attention to the dash. About 10 minutes later I went to restart the vehicle to leave and I noticed the check engine light on. Since the vehicle seemed to be driving okay I thought I could make it home and check the car's computer to see what the issue was. As I was leaving the parking lot I stopped at the end of the parking lot to look before pulling out onto the road and the Blazer said shift to neutral and restart the vehicle. When I did that the vehicle would not start. It would just crank and crank and then it would finally start for a few seconds. I was going to back my vehicle up out of the road but each time I would try the car would die. I am very thankful this did not happen on the highway or even on the freeway. A friend and myself had to push my vehicle back into a parking spot. The DTC code is a P023F. When this happens, you can't technically shift the vehicle into neutral to push it out of the way because the car has to be running to shift. I was able to force it into neutral, however. I made an appointment with Awesome Chevrolet in Chehalis WA and had to have it towed to the dealer. They stated it was the fuel pump module. I had at that time 18,388 miles on the odometer. Unfortunately, I no longer feel safe with this vehicle in case it happens again. Where I am hours from home or on a 2-lane road or freeway. The fuel pump module failure appears to be a known issue with GM vehicles. The fuel pump module was replaced and was able to be replaced under warranty. I hope that it does not happen again. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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 Jun 15, 2024 · Engine · MI

Leaking coolant from bad radiator “just out of warranty”. Roughly $2000 repair estimate

Filed May 7, 2024 · Engine, Transmission · 63,000 miles · NY

The contact owns a 2021 Chevrolet Blazer. The contact stated that oil was leaking from the vehicle. There were no warning lights illuminated. The vehicle was taken to the local dealer, where it was diagnosed that the cam shaft carrier needed to be replaced. The vehicle was repaired, but the failure recurred. The vehicle was taken to an independent mechanic, who determined that there was a separation in the transmission, oil cooler line, valve, and hoses that needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and submitted a complaint. The failure mileage was approximately 63,000.

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

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