2020 Chevrolet Blazer engine problems

Filed Oct 22, 2026 · Engine, Steering · MI

2020 Chevy Blazer LT 3.6 L V6 I'm filing this complaint regarding multiple concerning mechanical and safety related issues with my 2020 Chevy Blazer LT that I purchased brand new and currently have 54,224 miles . Without warning, My vehicle developed several problems simultaneously. The check engine light came on, The engine cooling fan started running continuously at high speed, the AC stopped blowing cold air and is warm air, the steering assist reduced came on and my chevy app notified me that I have an engine cooling system malfunction and to service now. It's showing a P0128 code when I had it checked. After doing some research, I discovered GM issued a thermostat special coverage program for certain vehicles 2021-and newer models. Mine isn't part of it because of the year and isn't covered by the power train warranty for the same reason even though they all have the same engine. I only have 54,000 miles! I'm very concerned over the steering assist being reduced! What if the steering goes out while I'm driving? I have my grandchildren all the time. I need my car! There are several other complaints on here for the same vehicle and the same problem! Why isn't the 2020 Blazer covered under this special coverage program? The dealerships all say it's a well known problem! I believe this issue deserves investigation !

Filed Oct 8, 2026 · Engine, Steering · TN

The thermostat is malfunctioning along with engine temperature coolant sensor. This causes the temperature gauge on the dashboard to be completely disabled and not moving off cold, it disables the air conditioner, makes the engine cooling fan to run extremely high nonstop, and places the vehicle into an unpredictable limp mode or fail safe mode. This was identified as faulty by GM and they have issued a special service bulletin that they will repair it up to a 150,000 miles or 15 years or reimburse customers up to $1200 on 2021 models. The 2020 models use the same engine and parts but they refuse to include them which is an unfair exclusion since they admitted to a faulty part. 2020 should be included with the same 150,000 miles and 15 year coverage or reimbursement.

Filed Oct 1, 2026 · Engine · IL

The radiator and thermostat on my 2020 Blazer had to be replaced at less than 35,000 miles. It was out of warranty and the Chevy dealer charged me $3,500 to replace them. Internet sources state that this is a common problem with this car. I complained to Chevy corporate and they refunded $1,000. I do not feel this was a fair settlement due to the fact that it is a common problem.

Filed Sep 14, 2026 · Engine · 119,000 miles · OH

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.

Filed Jul 10, 2026 · Brakes, Engine · AK

I was driving and steering reduced drive with caution notification and brake assist notification came on and then engine light and the temp gage went to cold and stayed there. My steering stiffened up making it hard to steer. This is a known problem with the Chevy blazers and it had to do with the thermostat needing replaced.

Filed Jun 23, 2026 · Electrical, Engine · IN

The vehicle experiences a constant cooling system failure that appears to be related to the thermostat. Beginning at approximately 40,000 miles, the engine cooling fan started running continuously at high speed whenever the vehicle is operating. At the same time, the air conditioning stopped functioning properly and the vehicle began displaying a warning message indicating that steering assist is unavailable or reduced. The vehicle is available for inspection upon request. This condition creates a safety concern because the steering assist warning indicates a potential reduction or loss of power steering assistance, which could increase steering effort and make the vehicle more difficult to control, particularly during low-speed maneuvers or emergency situations. The warning appears during normal vehicle operation and can distract the driver. The ongoing failure of multiple vehicle systems raises concerns about the safe and reliable operation of the vehicle. The problem has been present continuously since first appearing at approximately 40,000 miles and is fully reproducible. The condition occurs every time the vehicle is driven and has not corrected itself. Symptoms include the engine cooling fan running continuously, loss of air conditioning, and a steering assist warning message. Based on reports from other Chevrolet Blazer owners experiencing similar thermostat-related failures, this may represent a common defect that warrants investigation and consideration for a safety recall.

Filed Jun 5, 2026 · Driver assistance, Engine · AR

Engine temp gauge bottoms out because the thermostat is stuck open, causing the air to stop working. Also a warning that the steering assist is reduced. Eng check light comes on with a code P0208. This a known problem with an extended service # (N242484760) but only if your vin is listed. All vehicles with this problem should be covered

Filed May 27, 2026 · Engine, Transmission · MI

Engine temp gauge stops working causing the air to stop working and the cooling fan to rev to highest rpm. Also a warning that the steering assist is reduced. Eng check light comes on with a code P0208. This a known problem with an extended service # (N242484760) but only if your vin is listed. All vehicles with this problem should be covered

Filed May 23, 2026 · Engine, Steering · IN

P0128CODE P0024 CODE SECOND Cam Shaft sensor failure Thermostat failure, stuck open Electrical issues from low battery power Failure to shift to park when shutting off vehicle

Filed May 18, 2026 · Engine, Steering · MS

P0128 code produced when scanned. Cooling fans on high. No ac. Steering Assist Warning. Had to replace the thermostat. ECM also replaced and caused the tire pressure sensors to fail and had to replace the tire sensors. There is a recall on models 2021 to 2025 but none on the 2020 for the thermostat. I have paid $3500.00 to have my vehicle fixed.