2025 Toyota Grand Highlander: engine overheating

Filed Sep 28, 2026 · Engine · TX

Engine temperature overheated during long idle on an out of town event. The vehicle put in park and engine running in idle with AC running. Vehicle coolant temp reach high mark in the red area. Vehicle temp alarm gave a warning to shutdown. I estimated the car idle time 40 min due to traffic accident ahead. The incident occurred on 9/11/26. The car was taken to dealer 9/17/26 for checkup/diagnose the issue. Dealer stated, they could not duplicate the issue. But they did my find the vehicle computer log, the engine registered high temp.

Filed Sep 18, 2026 · Engine · OK

A piece of road debris/rock struck the radiator/heat exchangers in my 2025 Toyota Grand Highlander Hybrid that immediately damaged the radiator/heat exchangers to result in coolant leakage and sudden loss of propulsion and terminated the engine from moving and required a tow to a Toyota dealer and thus a replacement of the heat exchanger/radiator. It came apparent from their experience that the design of the front-end grill has large, open apertures and no protective screen between the grill and the vehicle’s heat exchangers. Had to file an insurance claim under comprehensive coverage that required me paying a deductible for repairs and NOW stress in future driving experiences.

Filed Sep 8, 2026 · Engine · 14,300 miles · MT

The contact owns a 2025 Toyota Grand Highlander. The contact stated that while driving approximately 35 MPH, another vehicle struck a rock, and the rock went through the front grille of the vehicle and punctured the inverter radiator, causing a coolant leak and a loss of motive power. The message "Hybrid System Malfunction" was displayed following the loss of motive power. The vehicle was towed to a dealer, where it was diagnosed and determined that the inverter radiator had sustained a puncture and needed to be replaced. The vehicle was repaired. The contact associated the failure with the federal safety agency Action Number: DP26006 (Engine and Engine Cooling). The failure mileage was approximately 14,300.

Filed Sep 4, 2026 · Body · 12,200 miles · OH

The contact owns a 2025 Toyota Grand Highlander. The contact stated that while driving 60 MPH on the highway with a three-year-old child in the vehicle, the message "Pull Over Immediately and Shut Off the Vehicle" was displayed. The contact was able to pull over to the side of the road and waited for a tow truck in hot weather. The vehicle was towed to a dealer, where it was diagnosed and determined that the radiator was punctured by a rock that had gone through the front grille and caused a coolant leak. The dealer determined that the radiator needed to be replaced. The vehicle was scheduled for the repair. The contact informed the dealer that the failure was a common issue associated with the federal safety agency Action Number: DP26006 (Engine and Engine Cooling); however, the dealer informed the contact that the manufacturer was not aware of the issue. The failure mileage was approximately 12,200.

Filed Aug 22, 2026 · IL

My wife was driving and a small rock passed through the front grill puncturing the radiator and causing her check engine light to come on. Within 5 minutes the coolant leaked out and the car was undrivable. We took it to Bredemann Toyota in Park Ridge who replaced it.

Filed Jul 14, 2026 · Electrical, Engine · NM

Radiator issue summer of 2025, when in back to back traffic at low speeds my vehicle overheated at a stand still took vehicle in to dealership with no real answers. The following summer 2026 same scenario but the engine was smoking. Took into dealership and they stated the connection for the radiator fan was disconnected which meant it was not colling the engine. A month later the AC is blowing hot air when AC is set to the coolest setting, scheduled another appt with dealership likely another radiator issue. Fuel gauge inaccuracy. Manual states 17 gallon tank capacity but my car states empty and can only fill the tank with 14 to 15 gallons. Dealership had no help and stated it does that to protect the hybrid engine. Transmission shifting issues, in the summer hotter temperatures I notice at times the transmission has difficulty shifting in lower gears and really revs up the RPMs to shift sometimes. At times the the transmission shift is jerky or harsh when going speeds form 20- 40 mph.

Filed Nov 4, 2025 · OR

There is a coolant leak in the hybrid radiator caused by a puncture. When taken to the dealer, they said a rock must have punctured it. The dealer currently has the part. Me, my husband, and 2 children were driving on I-5 when the car stopped accelerating and a "hybrid malfucntion" code and "engine malfunction" code started flashing. Prior to this, there were no warnings. I was thankfully able to full over safely, but we were stuck on the side of I-5 for at least an hour waiting for a tow. I am reading online that this is an issue with the car and seems to be a design flaw. The gaps in the grill are too large, and there is no mesh or anything else behind the grill to protect the front end of the car.

Filed Aug 20, 2025 · TN

Apparently, a rock flew into the front grill striking the radiator (which is located directly behind the grill) and put a hole in it. This caused fluid to leak and fortunately during a routine maintenance check (my first service) on 8/15/25, it was discovered. The car was deemed not safe to drive until repairs were made. I submitted it to my insurance company and they inspected it and verified the issue. The radiator was replaced by Toyota at the dealership where I purchased the vehicle. They said they heard of a few cases, but I went online and discovered several vehicles that had this happen. Apparently the grill on the new highlanders is the issue - it has wide openings and the radiator is directly behind it. I am purchasing a bra and some mesh to place behind the grill in order to prevent another incident. No warning lights or indicators came on and the dealership said it would've eventually when it got hot enough. Fortunately, most of my driving was local after the incident occurred so the vehicle didn't have time to overheat. I am thankful it was discovered before I was stranded.