Engine And Engine Cooling Problems of Chevrolet Blazer - part 1

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.

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The contact owns a 2023 Chevrolet Blazer. The contact stated that while driving 10 mph and pulling into a parking lot, the sun gear and the drive shaft fractured. The vehicle became inoperable. The vehicle was pushed to a safe place. The check engine warning light illuminated after the failure. The contact associated the failure with NHTSA campaign number: 23v172000 (power train). The vehicle was towed on a flatbed to the local dealer. The vehicle was not diagnosed or repaired. The dealer provided an estimate for the transmission replacement. The manufacturer was contacted and confirmed that there was no recall coverage on the VIN for the failure. The manufacturer referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 107,000.

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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.

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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.

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.

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.

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.

The check engine light came on with a warning that said "steering assist reduced drive with care". The temperature gauge went to cold and the air condition quit working.

Thermostat stuck open radiator broke. Told by 4 gm dealerships, this is a very common problem in a gm 3. 6l v6. Gm even claims it's common in its tech advisements. The "stuck open" glitch (p0128 code).

Car is overheating with multiple engine codes. Unable to drive. Car power is reduced and shortly after will start overheating.

Vehicle safety defect complaint – 2023 Chevrolet Blazer to whom it may concern, I am submitting a formal safety defect complaint regarding my 2023 Chevrolet Blazer. This vehicle has exhibited multiple system failures that present a serious risk to driver safety and public roadway safety. The vehicle was purchased new on July 20, 2023. Beginning on April 21, 2025, at approximately 27,610 miles, the vehicle developed a progressive defect initially presenting as oil-related issues. Despite multiple repair attempts, the condition worsened and required a full engine replacement in January 2026. Following the engine replacement, the vehicle continued to experience critical safety failures, including engine stalling, reduced engine power warnings, and electronic stability control (esc) alerts. On April 26, 2026, the vehicle experienced a driver assistance system malfunction in which it attempted to steer off the roadway. I was forced to manually disable the system to maintain control of the vehicle. On April 27, 2026, the vehicle exhibited a fuel system failure, including fuel leakage and fuel odor, along with multiple simultaneous warning indicators: • reduced engine power • service esc • steering assist reduced / drive with care • power assist driver system disabled this combination of failures presents both a fire hazard and a loss-of-control risk. Additionally, I was informed by the dealership that a high-pressure fuel line, a one-time-use component, was not replaced during the engine installation. This raises concerns regarding improper repair and continued unsafe operation of the vehicle. The vehicle has undergone multiple repair attempts and a major powertrain replacement, yet continues to present serious safety concerns. Due to these ongoing issues, I do not feel safe operating this vehicle. I respectfully request that NHTSA review this matter for potential safety defects that may impact other vehicles of the same make and model.

The contact owns a 2024 Chevrolet Blazer. The contact stated that while driving 20 mph with 100 miles of charge, the vehicle stalled and shut off. The screen was black, unresponsive, and failed to start. The vehicle was towed to the local dealer, where it was diagnosed with a power module failure. The part was on back order. The electric module was previously replaced. The vehicle was not repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was 10,381.

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I have a 2022 Blazer with a 3. 6 engine. The thermostat has failed and dealer says only certain Blazer vehicles are covered under aspecial warrnty exstesion. I know several people having the same problem. I have a check engine light, with a scan shows code p0128(thermostat0. I also have a display of power steering assist reduced and tempature gauge stays much lower than normal. . When you turn vehicle off the high speed cooling fans remain running ub=ntil battery is dead.

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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?.

A/c quit working, "caution power steering assist . . . . Working, temperature gauge reading zero ( far left side of gauge. Pf62f code set. Repair shop says very common. $800 to repair due to removal of plenum and other component including water temp sensor and thermostat while your there. $100+. 63k miles on vehicle.

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.

I have received this warning a few different times “steering assist is reduced". Which causes my vehicle to not blow cold air when ac is on. Fans are louder than normal. And when I turn off my vehicle fans continue to run for roughly around 8 minutes.

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.

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 vehicle will not shut off when you shift to park. You are forced to sit in the vehicle for extended periods of time attempting to get the vehicle turned off. Apparently chevy is familiar with eat problem and there are pending class action law suits in ohio. According to the dealership chevy has acknowledged there is a defect but no recall has been issued. We have had this issue for about two months and it is getting worse.

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My drive assist stopped working. Then my air conditioning stopped blowing cold. Then the temperature gauge stopped working. Upon turning the car off the fan continued to run for several minutes. Took to repair shop where it required a new thermostat housing, coolant temp sensor and coolant flush. The total cost for repair was $1,131. 52. The car has 37,000 miles on it. Barely out of warranty. This is a well-known issue among chevy owners.

Just took my car to the chevy dealership today and had them go over the car because I keep getting the message steering assist has been reduced and the fan is constantly running at the highest speed and it also makes it where I can not use the a/c or heat in the car! I don’t know the code off hand but it has something to do with the cam shaft and the thermostat for the antifreeze! from what chevy told me today it is a $9000 job to tear down the left side of the engine because the camshaft carrier gasket is leaking oil! which is probably why that code is popping up. Or from what I was told today it could be from the battery which I believe they were trying to shift blame. Either way this camshaft stuff really needs to be investigated!!.

I was driving to work as I normally do and work is only 15 miles away from home I get to work turn into the parking lot stop to scan my badge and I hear knocking noise I thought it was coming from the truck in front of me but after he moved on I still heard the noise and I found a parking spot as soon as I could and the engine light on the dash came on and the motor that was knocking is definitely my Blazer with only 11,222 miles on it. I always keep up on my vehicles maintenance in fact I just had the oil changed at ray skillman gm dealership2/16/26 it had 10,960 miles on it. Before that I had the oil changed at ray skillman 08/20/25 it had 7,720 miles on it then and before that. The very first oil change 22/ may /25 the mileage was 5,354 on it was at hare Chevrolet where I purchased this Blazer rs brand new it had 34 miles I always get the oil changed when it gets to 25%.

| issues first appeared recorded on 3/9/2026, while odometer read 49,663 miles. Check engine light was caused by error codes p0128 and p01f0. This causes the following issues: * check engine light to appear on the dashboard. * engine temperature gauges to be unreliable at times or completely non functional at others, as it will constantly read the engine temperature "cold". * air conditioning unit to become unreliable at times or completely non functional at others, and only blow hot air. * radiator fan will be stuck running at max speed despite current engine temperature. * a "reduced steering assist" message will periodically appear on the dashboard. * a "service esc" message will periodically appear on the dashboard. * remote start will becomes non functional. | car was taken to a license Chevrolet dealership and had full thermostat housing and thermostat sensors replaced. Dealership confirmed all replaced parts are working correctly and as intended. After picking up the vehicle from the dealership, and driving car for roughly 30 miles, the check engine light appeared on the dashboard again causing all previous issues to return. | several other chevy Blazer 2020 owners have complained of the same issue online, and in forums such [xxx] . | information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Electronically controlled thermostat and sensor fail or get stuck at a much lower coolant temperature causing the dash to display the “steering assist is reduced drive with care. ” it isn’t just a message, the steering is much harder to use potentially causing an accident. The ac completely doesn’t work causing potential for sensitive, elderly, or young children and pets to overheat inside, it’s significant risk of injury or death from the hot summer temperatures. The engine coolant temperature gauge is all the way down on c position which isn’t registering how hot/cold the engine gets potentially causing damage to the vehicle and a total loss of the vehicle entirely due to damage from the engine overheating. Gm sent out letters to 2021 Blazer owners which included a special coverage number n252508350 applying to people with this year having this problem and they have until 2036 or 150,009 mi to get the repairs made free of charge, they just bring the document with the special repair codes to the dealer and they fix it free of charge. After doing research online, this problem is affecting all years of the 2019+ Blazers with the 3. 6l v6 engine and other known problems with other models and years of their other lineup of cars, it’s very widespread across their platforms. So what are people supposed to do when it isn’t the 2021 year? pay an $800+ repair bill to gm when they know it’s more widespread than just this year/make? this is a scam. I can’t even do the repair myself because I’m having trouble finding the correct parts online and not only that the repair is extensive, the whole top half of the engine needs to be taken apart just to get to the thermostat, we’re talking the airbox and intake manifold, all the plastic parts and shrouds and sensors covering engine, the fuel rail and injectors, pipes and clamps, engine coolant needs drained and refilled. It’s a major fix. I’m reporting this complaint to raise awareness and hopefully gm will do the right thing.

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.

2020 chevy Blazer rs 3. 6l having intermittent issues with ‘check engine’ light activating and giving code p0128 - indicating “coolant thermostat (coolant temperature below thermostat regulating temperature)”. Symptoms include: - temp gauge drops to reading “c” (cold), - ac blows warm/hot air, - dash displays message, “steering assist is reduced, drive with care”, - radiator (electric) fans run full speed. It seems that the computer is interpreting the engine coolant temperature sensor drop as a ‘stuck open’ thermostat, thus the indicated code. However, at the same time it also appears to assume a bad coolant temp sensor, and failsafes to disable the ac and set the radiator fans to max to avoid potential overheating. The problem with this is that this can occur after driving for some period that the engine is suitably warm, then I can pull off the road, disconnect the battery for a few minutes, and everything goes back to normal operation. A broken thermostat would not behave this way. * this happened in Mar 2025 - after disconnecting the battery about 5-6 times over about a 1wk period the code cleared and we were able to pass inspection. The issue did not reoccur until about the same time this year. It has been recurring periodically since. * after reading numerous postings on this issue, with numerous different vehicles that have this engine and computer, I have no faith that the dealership will provide a solution other than charging me to replace the thermostat, and ending up with the same problem a few weeks later.

Faulty thermostat. Check engine light comes on due to thermostat getting stuck open and needing to be replaced. This is terrible for the engine and the environment.

On two separate occasions the vehicle lost all power while driving. On December 5, 2025 turning on to a main road from parking lot the vehicle shut off with no prior warning lights. Shifted vehicle to park. No power to anything, unable to unlock doors, unable to turn on hazard flashers, stuck in the middle of the road at night. Waited a minute and pressed the start button and vehicle started with no problem. Again, on February 24 , 2026 making a left turn in intersection, without any warning the vehicle shut off… no power at all. Stuck in middle of road with no lights , no hazard flashers ,unable to get out of the car. Few minutes later vehicle started again. The vehicle did not stall while stopped, it completely lost power while moving. Reported problem to west herr Chevrolet of hamburg NY , brought vehicle in to dealership on February 25, 2026 and they were “unable to duplicate the concerns” the dealership paperwork states that the vehicle stalled while stopped, this vehicle lost all power while it was moving. We now have the vehicle back in our possession but are extremely concerned for our safety and the safety of others.

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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.

When shutting off the car, the fan continued to run. I started the car up again to see if this would allow the fan to turn off. No luck. The steering assist was dis-enabled on the dash. I took my car to the dealer to find out that it has a bad thermostat and that my radiator was leaking. The thermostat was covered but I had to use my extended warranty to pay the additional repair. My deductible for my extended warranty is $300. 00. My daughter has a 2021 chevy Blazer and the same situation happened. There was a recall and all her parts were covered.

Thermostat housing replacement + dexcool: p0128, thermostat stuck. Was told this can cause engine to overheat.

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.

On February 4, 2026, my wife drove to the bank, a trip of about 10 to 15 minutes, and turned off the car at the atm. When she tried to leave, the vehicle wouldn't start. After a while, she opened and closed the door and locked and unlocked the car twice with the remote control, and the vehicle started and she was able to drive, but all the warning lights on the dashboard remained on. It is currently at a Chevrolet dealership for diagnosis.

Radiator leak from the bottom left corner (driver side). Slow leak over time, no visible damage (per the service department), likely a manufacturing issue. Entire radiator required replacement.