Toyota Highlander overheating problems

Filed Oct 26, 2026 · Engine, Transmission · MD

While driving, my vehicle experienced a severe and sudden failure of the Aisin UA80F 8-speed automatic transmission. The transmission exhibits erratic and hard shifting, severe hesitation, and a dangerous delay in acceleration when trying to merge into traffic or accelerate from a complete stop. Frequently, the engine revs high, but the transmission fails to engage the gear promptly, resulting in a sudden, violent lurch forward when it finally catches. Furthermore, the vehicle intermittently loses motive power entirely while in motion, forcing me to coast to the side of the road. A loud, high-pitched whining noise is audible from the transmission assembly, and diagnostic checks indicate internal mechanical overheating and premature component wear.

Filed Sep 30, 2026 · Transmission · 130,000 miles · CA

The contact owns a 2018 Toyota Highlander. The contact stated that while driving 75 MPH, there was an audible chime followed by the message "Transmission Overheating". The vehicle started jerking and hesitating while depressing the accelerator pedal. Additionally, there was a burning odor coming from the vehicle. Due to the failure, the contact pulled off the highway and allowed the transmission to cool down. The vehicle was restarted, and the message disappeared; however, the vehicle continued to hesitate while depressing the accelerator pedal. The contact continued driving 70 MPH, and the transmission message displayed again. The vehicle was then taken to a dealer, and the failure was associated with Customer Support Program: ZJC. The contact was informed that the vehicle was not included in the program. The manufacturer was notified of the failure, and the contact was provided a case number. The manufacturer confirmed that the vehicle was not included in the CSP. The failure mileage was approximately 130,000.

Filed Sep 27, 2025 · Engine, Transmission · CA

On September 2, 2025, the vehicle’s Hybrid System shut down on cold start and the vehicle would not start. A dealer inspection reported coolant had entered cylinder #4, allegedly causing the engine block to warp, the cylinder head to crack, and the head gasket to fail. This was a sudden catastrophic engine failure on a five-year-old vehicle with no prior overheating warnings, no dashboard alerts, and no performance issues in the days leading up to the failure. It is highly unlikely for an engine block to warp without sustained overheating, yet the failure occurred on a cold start. The dealership itself described this as a “premature failure” in their service report. At approximately 26,000 miles, the vehicle’s coolant thermostat failed and was replaced under warranty. If the thermostat stuck closed even briefly, the engine could have experienced one or more silent overheat events that never registered on the dashboard. In aluminum blocks, even short bursts of high localized heat can create latent distortion that doesn’t cause immediate problems but can eventually lead to catastrophic failure years later. Safety Risk: – Vehicle became disabled suddenly without warning. – Engine failure occurred without overheating symptoms, creating risk of sudden shutdown during use. Problem Confirmation: – Engine failure confirmed by a Toyota-authorized dealer. – Dealer service report explicitly called this a “premature failure.” Warning Lamps / Symptoms: – A check engine light appeared briefly three days before failure, then cleared on its own. – No overheating warnings or drivability issues were observed prior to failure.

Filed Feb 18, 2025 · Engine · MO

2GR engine family in general used in Toyota and Lexus, may have a MANUFACTURING defect as per google about the 2GR-FE engine subtype Yes, the Toyota 2GR-FE engine, a 3.5L V6 found in many Toyota and Lexus models, is known to have a recurring issue with head gasket leaks, particularly where coolant leaks externally from the engine block due to corrosion around the cylinder head where the coolant port is located; this is considered a common problem with this engine type. Key points about the 2GR head gasket issue: Leak location: Coolant typically leaks outside of the engine block, visible as stains on the block surface, rather than internally into the combustion chambers. Cause: Corrosion around the cylinder head near the coolant port, often exacerbated by road salt and old, acidic coolant. Prevention: Regularly changing coolant and occasionally hosing down the engine block, especially if you live in a region with heavy winter road salt. Repair: Replacing the head gasket usually requires removing the engine, making it a major repair job. So TOYOTA should be held liable for REPAIR COSTS and LABOR as well as the PAIN and SUFFERING a consumer has to go through, seeing all the drama of the TOYOTA

Filed Mar 14, 2024 · Seat belts · AZ

The ECU requires a reflash or replacement. The hybrid batteries over heat and regen braking randomly shuts off during braking or before/after due to overheating becuswe the cooling fans do not engage past level 1 or 2. The fans in fact never go full speed unless commanded by a Toyota service tech via the software during fan testing. Upon testing I noticed they not once went high enough to be audible and thus overheated. Manu forms indicate this is a common issue and requires 180-$300 for a reflash and/or replacement of the compu) ECU to alleviate this issue. Second issue I've found is the 3rd row seat belts just like some other MY Highlanders have their restraints cut at the shackle holding them to the body of the vehicle. I have seen several sheered this way including my own vehicle.

Filed Mar 14, 2024 · Engine · AZ

The engine burns Coolant and yet doesn't overheat. The engine on cyl 4 misfires. Changing the head gasket didn't repair the issue, replacing all fuel Injectors and ignition parts didn't either. Heads inspected and passed. Compression testing passed. Always misfires on cyl 4. No repair aside from an ecu reflash or replacement seems to be possible. 4 shops looks at it and couldn't find any reason why it was misfiring and no traces of water were found in the interior, on the floor, in the oil or exhaust in the cooling system.

Filed Jan 3, 2024 · Engine · GA

The issue started when the car was over 84,000 miles. The engine burns excessive oil. I have to add oil every 2200 miles. When I press on the gas pedal to rev the car, oil come out of the tail pipe. When I went to the dealer that they are aware of the issue but they did not make any recommendations. Online several owner of this model have changed the engine or replaced pistons. I have never gotten the check light on even when no oil is on the dip stick. I have to check the oil every time I fill up my gas tank as a precaution. My concern is that I could be stranded or the car overheat and cause a fire.

Filed Nov 18, 2022 · Engine · NC

This is the second major failure I have experienced with my 2017 Toyota Highlander. I have already filed a complaint about the transmission failure earlier this year. On November 14, 2022, I noticed a knocking sound coming from the engine. My husband was able to ascertain that the noise was coming from the water pump and that the water pump gasket had failed. He checked the coolant fluid and all coolant fluid had leaked out, both the reserve tank and radiator had NO coolant fluid remaining. If I had continued to drive the vehicle, it would have overheated and possibly caused more damage. Thanks to the cooler temperatures we have in November, I did not experience the engine overheating. There were no warning lights or any other indicator that something major was wrong with the vehicle. We called our Toyota dealership and were told that the vehicle which now has 50,100 miles, is out of warranty and we would be responsible for the repair. The normal life of a water pump is over 100,000 miles and with this complete failure of this major system, I do not trust the safety of this vehicle with this being the second major system to completely fail in this vehicle.

Filed Jul 7, 2022 · Engine · FL

I can see many complaints similar to mine on line since the car was built in 2006. Driving on a 7hr trip when engine light came on and car overheated. We had to pull over on a busy highway and wait for car to cool down and light to go off. It was scary since I had my child in the car and traffic was moving at 60 mph. The next day I had the Toyota dealer charge me $160.00 to tell me coolant and oil were leaking from the head gasket and the bolt corroded and listed out causing a sealing issue. We just had the car in their shop doing thousands of dollars of maintenance and had a full inspection done in preparation for this trip. We also had fluid leaks from the engine twice before at 65819 miles and again at 84458 miles. No mention of this issue was ever brought up by dealer. I have full records and always did maint as suggested. so now the dealer says it will need a used engine at a cost of $9,000+. I am now without a car. This car should have been recalled and repaired, now it is totaled it. Thank goodness we were not injured or hit by another car on the interstate. sorry unable to send a copy of repair estimate done at Daytona Toyota 386‑255‑7475

Filed Jun 8, 2022 · Engine · AZ

When bringing my 2021 Toyota Highlander Hybrid AWD with ~18,000 miles on the odometer to the Toyota dealership for a flat tire and recall, they performed a routine multi point inspection. They found the inverter radiator was punctured and was leaking coolant. They said to fix it would be $1,640. The service representative text me “the technician also noticed that the inverter radiator is leaking coolant, which is a very important and vital part of the hybrid system. It looks to be that a rock from the road was the source of the damage, which since moving down here [AZ] I’ve seen happen quite often….I would strongly advise against driving the vehicle that far (~200 mi) for fear of it overheating and causing more damage. The technician said will end up happening is…the vehicle will overheat and shut down to save the inverter from further damage. This is a very, very important part of the hybrid system. “ When I asked the technician how a rock could cause the puncture and cause the coolant to leak without my knowledge, she said “it sits right behind the front grill and it’s pretty easy to get hit by a rock when you’re driving.” I told her that sounds like a design flaw and asked if there’s a part that can protect this from occurring again. She didn’t know of any Toyota parts to reduce this reoccurrence, but suggested I could look online to buy an aftermarket part. What’s alarming are the photos of the damage and the coolant spraying out from the leak all over the inverter radiator, how much coolant was lost due to this damage, and that I never had a warning light or notification. The car was driving fine and had no warning lights until I got a flat tire the day before the Toyota dealer found the inverter puncture.