2021 Chevrolet Blazer
The Verdict
The 2021 Chevrolet Blazer has 123 owner complaints filed with NHTSA. The most reported issues are engine (51 complaints) and body (23 complaints). With a Klunk Score of 69/100, it earns a "Solid Pick" rating. If you're shopping for a Chevrolet Blazer, consider the 2005 model year which has 87% fewer complaints.
Safe Bet
The 2005 has 87% fewer complaints
View the 2005 Chevrolet Blazer dashboard →
Klunk Score: Solid Pick
Fewer complaints than most vehicles. Generally dependable, but check the top problems below.
How is this calculated?
The Klunk Score ranks this vehicle year against all others in our database based on total owner complaints filed with NHTSA. 100 = fewest complaints (top tier), 0 = most complained-about. Scores above 60 are better than average; below 40 means more problems than most.
Get notified if a recall hits this car.
We email you when NHTSA issues a new recall on the 2021 Chevrolet Blazer. No spam, no marketing.
Under the Hood
Each number is a complaint. Darker = bigger problem.
By Category
By Severity
Worst Problems
Complaints
July 4th the car had gas, turned over, but would not start. I had it towed to a repair center who towed, did diagnostics and came up with the codes for a bad fuel pump control module. It was replaced and the car starts. There was no warning. Problem was confirmed by an independent service center. All documentation is available.
fuel pump control module failed at 26000. recall number N252516900. This is a recall that other 2021 blazers have ben part of. Over 300000 recalls so far. GM says my car isn't. Ridiculous. They dont want to acknowledge their fault. I need a formal statement that this module should be recalled for my car.
The thermostat malfunctioned causing an error message regarding “steering assist is reduced”. When I parked and turned off, the engine fan continued to run. When car was restarted, the temp gauge inside was stuck at C. Took to dealership and they assessed. They repaired the thermostat under power train warranty, however there was a crack in the radiator (top) resulting in the need for a new radiator. This vehicle had 35,000 miles on it. Upon research online, it seems there are MANY people who have had this same issue and worse. It appears cars produced during COVID era are most affected. Chevy refused to warranty the issue. The dealership offered a small cost reduction (due to our loyalty). The thermostat and the radiator issues seem to be well known by Chevy, they just refuse to accept responsibility. Now we are out thousands of dollars on a basically “new” vehicle.
The thermometer and thermometer sensor are glitching . The engine temp needle will not rise at all, the engine fan will run the whole time driving and then when it is turned off will run for 10 min . Right before this happens a notice shows the guided steering is being limited. I disconnected the battery and it reset , I drove and there were no issues , next time I started my car the engine temp needle stayed down and the van started again. This car has 36k miles on it. I just bought it 2 days before it started happening
Lost coolant temp so replaced sensor with one from auto zone and worked for one then pegged to cold again fan runs 100% so went and bought another coolant temp sensor from Chevrolet installed that worked two pegged back to cold again fan 100% now going to pay $700.00 dollars to remove the two sensor wires for the harness all the two the Ecm heard with it being wrapped in the coil wires it gets electromagnetic static due to degradation of wires. Also Radiator started leaking after couple years but they want $3100.00 dollars for that.Was told extended warranty ran out three days before they discovered radiator leak.
The vehicle showed an error on the dash which stated "Action Required Steering Assist is Reduced Drive with Care" I tool the vehicle to the dealer I purchased it from McClusky Chevy at Kings Auto Mall in Mason Ohio. They informed me that the error code is C0460:58 and GM has a service bulletin 20-NA-215 which advises to replace the Steering Gear due to internal component interference. No one explained to me that this could cause catastrophic failure and lead to a crash before I left the dealership. They could not replace it as they said they do not have the part and it is on national backorder. Additionally they told me the repair would cost me $3,400. The vehicle has 42k miles on it and this repair is not under warranty as the warranty that would have covered it expired in March of 2026. I have taken the vehicle to a different GM dealer - Tom Gill GMC in Fairfield Ohio - they are waiting on the part and I have a case opened with GM regarding the costs. You would think that if there is a risk of a catastrophic failure which could cause harm to my self or someone else - the dealer would have an obligation to tell me so before i drive off. If not legally, certainly morally.
Driving on straight road going speed limit. Heard a pop behind me like a tire pop. Car fish tailed uncontrollably and ended up crashing into a Ranch Fence on the right side of the road. 2 of my kids and myself had injuries. When we got off the vehicle witnesses and I saw A rear link broken which keeps the tires straight.
I am reaching out regarding an ongoing issue with my 2021 Chevrolet Blazer. The vehicle is experiencing a noticeable stutter or hesitation when shifting between second and third gear. In addition, there are instances where the vehicle accelerates unexpectedly or more aggressively than intended. This behavior is particularly concerning, as it presents a potential safety issue during normal driving conditions. These concerns have become increasingly noticeable, and I am concerned they may indicate a transmission or related mechanical problem that requires prompt inspection and resolution. Please advise if there are any known service bulletins, recalls, or warranty coverage related to these issues. For reference, the vehicle has been properly maintained and this behavior is not consistent with normal operation. Given that this is now the third major issue I’ve experienced with this vehicle, I am hoping this matter can be addressed without additional out-of-pocket expense. After additional research, I have learned that other owners have experienced the same issue. Others have stated the following: 1. Hesitation, stuttering, or jerking between gears Owners of 2020–2021 Blazers report hesitation and jerking during acceleration, sometimes described as gears “shifting in and out rapidly.” Forum users mention sluggish shifting or slipping feelings, especially at certain speeds. Others report hard or delayed shifts at low speeds (like 15–25 mph). 2. Shuddering / vibration (often tied to torque converter) There are repeated mentions of “shudder,” “surge,” or vibration during acceleration. Some cases were linked to: Contaminated transmission fluid Torque converter clutch (TCC) issues One owner said the problem felt like a bad torque converter and required service attention. 3. Unexpected acceleration / lunging Drivers across GM vehicles (including similar transmissions) report: “Jerking,” “bucking,” or “lunging” during acceleration Some describe needing to
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?
Both camshaft carriers failed due to a manufacturing defect. According to NHTSA 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.
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.
123 total