Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2020 Chevrolet Blazer owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2020 Chevrolet Blazer. The contact stated while driving at approximately 55 MPH and driving up an incline in the road, the check engine warning light had illuminated. The contact stated that the vehicle was shuddering. The contact stated that the failure only occurred while driving uphill. The contact had only recently taken the vehicle to a local dealer because the check engine warning light was illuminated. The vehicle was diagnosed, and the dealer determined that the thermostat and the engine control sensor needed to be replaced. The vehicle was repaired. The contact stated that approximately 1,800 miles after the first repair, the check engine warning was illuminated again. The vehicle was taken back to the same dealer. The vehicle was diagnosed, and it was determined that the air flow shutters had been damaged and needed to be replaced. …
6/12/2024 In Damon Parking lot in Rochester MN. Going less than 10 miles an hr- cars in front of me and behind me looking for a parking spot. Stop and go at times. Went to turn corner to go from one level to the next and my BLAZER took off "like a bullet". No control over accelerated speed- hit outer cement wall and slammed into 2 parked empty SUVS. Could not go any farther. The 2 SUVs slammed into cement wall in front of them. Injuries to both my passenger and myself. I have no idea what happened - it was so fast- I do know I had no control over accelerated rate causing accident. My 2020 Chevy Blazer was totaled- It was inspected by American National Insurance CO. Absolutely no warnings. Police report did not include any witness. Blazer is in the hands of the Insurance Co. …
The contact owns a 2020 Chevrolet Blazer. The contact stated while driving approximately 45 MPH, the instrument cluster went black, and the vehicle stalled. The contact stated that there was no warning light illuminated or an audible chime heard. The contact stated that several attempts were needed to restart the vehicle. The vehicle was restarted, and the message "Vehicle in Transport Mode" was displayed. The contact stated that the failure was intermittent but reoccurred. The contact stated that the vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. The manufacturer was informed of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 92,000.
The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with VVT sensor failure. The sensors were replaced; however, the failure recurred. The vehicle was taken back to the mechanic, where a solenoid was replaced. The vehicle was repaired. The contact was informed that if the failure recurred, there might be an internal engine failure. The dealer was not contacted. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 70,000.
The contact owns a 2020 Chevrolet Blazer. The contact stated that while operating the vehicle, the check engine warning light intermittently illuminated, and the vehicle hesitated while accelerating. The vehicle was taken to the local dealer to be diagnosed, and the contact was informed that the catalytic converter needed to be replaced. The vehicle was not yet repaired. Additionally, while operating the vehicle, the engine temperature rose to HOT. The vehicle was taken to the local dealer, and the thermostat was replaced. The manufacturer was notified of the failure. The failure mileage was 119,000.
The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the steering wheel became inoperable. The contact stated that the steering wheel became difficult to turn with a reduced steering message displayed. The vehicle was taken to the dealer, where it was diagnosed that the thermostat had failed, which caused the steering wheel to fail, and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 54,000.
The contact owns a 2020 Chevrolet Blazer. The contact stated while driving approximately 30 mph, there was an abnormal noise coming from the vehicle. In addition, the check engine warning light was illuminated, and the vehicle failed to operate. The vehicle was towed to the dealer but was not yet diagnosed. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 15,000.
My 2020 Chevy Blazer began demonstrating possible problems with the transmission in November 2021 which have continued to date. The RPMs will rapidly increase and the car will feel as if it is jolting forward. If driving below 20 mphs, when I try to accelerate to a higher speed, the car will drag and then skip forward. I have videos showing this and have taken it to the dealership on two occasions but it couldn't be replicated and no codes show during diagnositics. The car is currently being repaired (at the dealership since 3/18/22) due to 3 separate concerns that are co-occuring which seems quite strange to me. The thermostat has gone bad, causing my check engine light to come on while driving (and having to have it towed). The car is also not recognize my remote key to operate the car. I am also getting "steering assist reduced" notifications while driving. …
Approximately three weeks ago, our 2020 Chevrolet Blazer's check engine light came on. It has a little over 63,000 miles on it. I took it to a private service garage where they diagnosed the code as P0128, or coolant system issue. They concluded that it was the thermostat. I did some checking on the warranty and it turns out that the warranty on this car expired at 61,066 miles. I then took it to Serra Chevrolet in Grand Blanc, MI where they diagnosed the same error code, or P0128. They took the car back to give me a service estimate and when they returned they diagnosed not only the thermostat as defective. This has become a common problem with this car and the 3.6 liter engine in particular. We have been told that this is a "known issue" by two different General Motors dealerships, specifically in their respective service departments. …
Ongoing Engine and Steering Sensor Issues - 2020 Chevrolet Blazer I am filing a complaint regarding repeated safety and mechanical issues with my 2020 Chevrolet Blazer. The vehicle's check engine light frequently turns on and off, and I have been informed by technicians that it is related to the thermostat system. This issue negatively affects the vehicle's performance and reliability. Additionally, the "Steering Assist is Reduced - Drive with Care" warning continues to appear while driving, even when weather and road conditions are normal. This error is reportedly due to a steering control assist sensor, and it raises serious concerns about the safety and handling of the vehicle. The alert causes uncertainty and could potentially impact the power steering functionality, creating a hazardous driving situation. …
Engine complaints in other Blazer years
Frequently asked questions
How common are engine problems on the 2020 Chevrolet Blazer?
NHTSA has 73 complaints about the engine & cooling of the 2020 Chevrolet Blazer, 33% of the model year's 222 complaints. The component named most often is exhaust system › emission control › catalytic convertor (1 mentions).
Is there a recall for 2020 Chevrolet Blazer engine problems?
No. NHTSA lists no engine & cooling recall for the 2020 Chevrolet Blazer, though it has 3 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2020 Chevrolet Blazer engine problems start?
Half of the complaints with a recorded mileage happened before about 70,000 miles, and 38% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 2 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.