2021 Chevrolet Blazer Owner Complaints

On [XXX], my 2021 Chevy Blazer broke down in the middle of traffic in a left turn lane when it tried to auto-restart. I was left stranded for 2 hours and had to call the local police to direct traffic around me. Upon towing to a local auto shop, and then another two to Carl Black GMC in Roswell, Georgia, I learned that the engine had completely seized due to a leaking radiator. They quoted me $14,000 in repairs between the radiator and a new engine. The vehicle had approximately 84,000 miles at the time and GM offered $3,000 to help with the engine. The car never threw a check engine light prior to the engine completely seizing. The coolant temperature gauge in the car also never showed temperatures above normal. At a few points, the car fan ran loud after turning the car off and I thought this might have been electrical. I sanded and cleaned the ground connection to the chassis which seemed to fix the issue. I also learned of Special Coverage N252508350-Engine Coolant Thermostat that was issued by GM which indicated this condition could be caused by a coolant engine thermostat that could open at a low temperature. I had planned to get it completed along with the fuel pump control module recall at my next opportunity. This issue with my car left my stranded in the middle of a busy highway with cars zooming around me. GM has known about the issue of leaking radiators in 2021 Chevrolet Blazers for years and has never done anything about it. Between their shoddy electrical systems and the radiator, these cars are of significant risk of seizing up in the middle of traffic with no warning like mine. GM has refused to replace these radiators or issue a recall becaus the repair is $2,000 and affects multiple lines of vehicles.

NHTSA ID

11775638

Incident

Oct 29, 2026

In February 2023 we noticed coolant on our garage floor. Car was taken to GM dealership was told radiator seams were leaking. Replaced radiator February 14th 2023 and car had 14,597 miles cost covered by GM warranty. On October 8, 2026 vehicle taken to second GM dealership for driver assist not working be careful. The cooling fan loud when car was turned off. Dealership told us the radiator was again leaking on the seams and will need third radiator (original plus two replacements). The car had 44,328 miles. Cost quoted was $2,125 plus tax and fees. Called GM service line and filed a complaint. They told me car is out of warranty and to ask dealership to give me a payment plan and/or reduce the price. After multiple calls to dealership they said they would give me a 15 percent discount as I am a loyal customer. My wife drives this car and transport two children almost daily. Worried we will lose drive assist when in use possible causing potential issues or accident.

NHTSA ID

11773173

Incident

Oct 8, 2026

Torque converters are going out and causing people to need new transmissions. I was told by dealership that evaluated mine this is a known problem! I’ve also encountered others who have same issue with their cars.

NHTSA ID

11772869

Incident

Aug 8, 2026

My wife and I were just driving and suddenly the motor started stopping installing. We managed to get over toward the curb and shut the motor off and restart it. Then it ran normal. When it did stall out, and we made it to the curb, it shut itself off. That was yesterday then this morning it started to do it a little bit when we left the house.

NHTSA ID

11771904

Incident

Oct 17, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at 35 MPH, a loud cracking sound was heard and there was gray coming from underneath the hood. The contact parked the vehicle. Additionally, the steering wheel failed to turn in the intended direction. Upon opening the hood, the contact noticed gray smoke under the hood. The contact's minor child was occupying the vehicle during the failure. The vehicle was taken to an independent mechanic, where the contact was informed that the AC compressor had melted, requiring replacement of the AC kit and expansion valves. The vehicle was repaired; however, the failure recurred and the ESC warning light illuminated on the instrument panel. The contact stated that the vehicle was unsafe to drive. The contact associated the failure with an unknown recall; however, the VIN was not included in the recall. The failure mileage was unknown.

NHTSA ID

11771320

Incident

Sep 27, 2026

Steering assist reduced light came on, fan kept running after shutting off, brought to dealer to see if it was covered under the gm special coverage for thermostat, they say the radiator needs to be replaced for a leak. I looked it was leaking a bit on the top driverside corner, not actively leaking but a bit of corrosion where it had. So they want to replace the thermostat(covered under gm special coverage), the fan and radiator also replaced. From what I have read online this is a known issue with these radiators leaking at the seams. People end up replacing the radiator multiple times and still leaks. How can they get away with selling these cars with junk radiators and not recalling.

NHTSA ID

11770208

Incident

Oct 9, 2026

The main instrument cluster where the speedometer and fuel gauge etc etc reside went blank during operation of the vehicle. I wasn't able to pull over safely until my destination was reached. Restarting the car seemed to "solve" the issue.

NHTSA ID

11768271

Incident

Jun 17, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed and making a turn, the vehicle lost braking functionality. The brake pedal was depressed to the floorboard. After exiting the vehicle, the contact became aware of a fluid leak underneath the vehicle. The "BRAKE Failure" warning light was illuminated. The manufacturer was notified of the failure. The vehicle was taken to a local dealer, where technicians diagnosed a fluid leak from the vacuum pump, causing the brake failure. The contact referenced NHTSA Campaign Number: 19V645000 (Service Brakes, Hydraulic) as a possible cause for the failure. However, the VIN was not included in the recall. The dealer replaced the vacuum pump, and the vehicle was repaired. The failure mileage was 120,000.

NHTSA ID

11768040

Incident

Sep 28, 2026

Mileage

120,000 mi

My 2021 Chevy blazer is leaking oil at 70,000 miles Chevy only recalled under special warranty for camshaft carrier it appears Chevy put in a glue for them seals that comes off unfortunately they don’t recall all blazers just some but I am having the same issue as that special warranty. It’s a safety concern because no oil in the car can blow up the engine .6500 to repair

NHTSA ID

11767069

Incident

Sep 25, 2026

Vehicle Information: 2021 Chevrolet Blazer 2.5L engine, VIN [XXX]. Odometer 118000 miles.Description of Incident: While operating the vehicle, the mechanical brake vacuum pump experienced a catastrophic internal failure. The drive gear housing shattered violently without warning, shearing off the end of the connecting engine camshaft. Because this was an instantaneous mechanical failure, the vehicles computer did not trigger any dashboard warning lights, check engine lights, or safe mode protocols prior to the failure.Safety Hazards and Component Damage: First, the total destruction of the vacuum pump caused an immediate compromise to the brake booster vacuum lines, resulting in a sudden, dangerous loss of power braking assistance. Second, the sheared camshaft breached the engine valve cover or head, causing the engines pressurized oil system to instantly dump all engine oil externally onto the ground. Third, shrapnel or violent structural torque from the instant engine seizure punctured or severed the adjacent transmission cooler fluid lines and compromised brake fluid lines, causing total loss of transmission fluid and brake fluid simultaneously.Request for Action: This failure mirrors the exact mechanical defects documented in GM Technical Service Bulletin 21-NA-268 and previous GM vacuum pump recalls like NHTSA Recall 19V-645, which excluded the 2021 Blazer. I am filing this report because the lack of an electronic warning indicator before a catastrophic mechanical brake and engine failure poses an extreme, immediate threat to highway safety. GM must expand recall coverage or issue a Special Coverage Adjustment for this model year. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11764895

Incident

Sep 13, 2026

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 NHTSA document and evaluate this complaint together with any similar complaints involving this model and model year.

NHTSA ID

11764652

Incident

Sep 16, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that a technician identified a radiator leak during an emissions test after smelling an abnormal coolant odor. The technician confirmed that the coolant had leaked from the vehicle. Prior to the discovery by the technician, the contact’s husband observed white smoke coming from the engine. The fluid levels were checked and were normal at that time despite the smoke. Additionally, the contact stated that the message "Steering Assist Reduced" was displayed on the instrument panel prior to the failure. The vehicle was not repaired. The dealer provided an estimate for the repair with 15% goodwill assistance towards the cost. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was 46,860.

NHTSA ID

11763020

Incident

Aug 1, 2026

Mileage

46,860 mi

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving 40 MPH, the vehicle stalled and was unable to be restarted. The vehicle was towed to the residence. The husband was a mechanic and discovered the 350-amp fuse failure. The fuse was replaced, and the vehicle was repaired. The dealer was not contacted. The manufacturer was made aware of the failure by phone. The failure mileage was approximately 68,400.

NHTSA ID

11761571

Incident

Aug 19, 2026

Mileage

68,400 mi

My 2021 Chevrolet Blazer RS equipped with the 3.6L LGX V6 experienced catastrophic engine failure at approximately 90,200 miles. The vehicle had no prior warning. The dealer diagnosed the timing chain / lift/ cam damage. I am requesting investigation into whether this represents a safety or durability defect affecting other vehicles

NHTSA ID

11759058

Incident

Aug 5, 2026

Car will not crank, stalled while cranked, throws code P023F

NHTSA ID

11758918

Incident

Aug 15, 2026

While idling in my driveway, the engine started to shake and the check engine light came on. Got it diagnosed and was told by a private repair center that we had lost compression in cylinder 4 and that it was not worth the repair and we needed to replace the engine. Got it towed to the dealership, Bill Fox Chevrolet, for a 2nd opinion and they confirmed what the private shop had said. Because the vehicle was well maintained with regular preventative maintenance, it was deemed the failure was not the fault of the owner. GM extended a goodwill warranty to help cover the cost of the engine replacement (70% coverage. We were 1 month and 2,000 miles past our warranty). They never told us root cause, only that it would have cost more money to repair it than it would be to get a new engine. The Blazer had been running fine up to that point and was my wife's main mode of transportation. The Blazer only had 62,000 miles on it when the failure occured.

NHTSA ID

11758482

Incident

Feb 2, 2026

All 4 tires exhibit signs of dry rot impacting the inner sidewalls of each tire. The outer layer is showing significant signs of sidewall separation. There is no sign of damage visible on the exterior side walls, if an inspection was not done on this date 08/20/26 the driver and others would have been at significant risk of injury or death due to catastrophic failure. The worst separation occurred in the front drive / steering tires. While lesser damage was visible on the rear tire the damage was also significant. The driver side rear showed the least damage with only a 2 inch separation. The other 3 tires showed 12 inches or greater separation. Images are available for review.

NHTSA ID

11758374

Incident

Aug 20, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at approximately 50 MPH, the vehicle struck a deer, causing severe damage to the vehicle's front end. The contact stated that smoke was coming from the center of the steering wheel; however, the vehicle's air bags had not deployed. The contact was transported to the local hospital and treated for chest injuries. The vehicle was towed to a local collision center. No further information was available. A Police report was filed at the scene. The cause of the failure was not yet determined. The local dealer and manufacturer were not yet contacted. The failure mileage was 52,661.

NHTSA ID

11753752

Incident

Jul 29, 2026

Mileage

52,661 mi

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed, and the transmission was slipping gears before the vehicle lost motive power. The contact stated that the vehicle failed to drive forward or move while in reverse. The check engine warning light was illuminated. The vehicle was towed to the residence. The contact, who was an independent mechanic, diagnosed the failure as a clutch solenoid failure. The contact stated that the transmission needed to be replaced. The vehicle was not repaired. The contact referenced an unknown recall; however, the VIN was not associated with a recall related to the failure. The dealer was made aware of the failure but provided no assistance. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 100,000.

NHTSA ID

11751752

Incident

Jul 16, 2026

Mileage

100,000 mi

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.

NHTSA ID

11749371

Incident

Jul 4, 2026

XXX 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. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11749347

Incident

Jul 4, 2026

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.

NHTSA ID

11745926

Incident

May 27, 2026

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

NHTSA ID

11745573

Incident

Jun 21, 2026

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.

NHTSA ID

11742425

Incident

May 6, 2026

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.

NHTSA ID

11738765

Incident

May 4, 2026