Toyota 4RUNNER overheating problems

Filed Sep 23, 2026 · Engine · TX

Head gasket failure. 2005 toyota 4runner generation are notorious for head gasket failure. Due to the poor manufacturing of the gasket it has been deteriorating and has allowed coolant to leak into the cylinder causing misfires and possibly more damage internally. including permanent mechanical breakdown or a completely ruined engine block. High risk of Hydrolock, Damaged Engine Bearings and Sludge, Severe Overheating, Catalytic Converter Failure. Any of these effects cause by this head gasket failure will be extremely dangerous to happen while driving. The vehicles is being taken to a independent mechanic 09/28/2026 for conformation diagnosis. And possible repairs. The check engine light showed the following code-P0300, P0302, P0304. The only symptom where misfiring and coolant levels depleting. The vehicle has not been inspected by the manufacturer, police nor insurance representative. Noticeable misfiring around the beginning of 2025 has just became more aggressive since 2026

Filed Jul 13, 2022 · Engine · OH

Vehicle radiator light came on, shortly thereafter (5-10 min) vehicle overheated. Waited for vehicle to cool down, then drove home. The following day drove the vehicle to dealership. After an inspection the dealer stated the heads are cracked and needed to be replaced. When I asked how this could happen to a car that is regularly serviced with only 90k miles his response was "the original heads were made of weaker metal, the replacement ones are upgraded. We haven't had any come-backs on the ones we've replaced". I then asked, well how many vehicles has this impacted? Sounds like this should be covered under a recall? His response "We've had quite a few in the past month or so, seems to be happening when vehicles get to the 70-80k range." Sounds to me like Mazda knew the heads were made from inferior products which is why they upgraded the part on newer models.

Filed Apr 19, 2022 · TX

On 4/8/22, the rear window of our 2009 Toyota 4runner just shattered and fell apart for no reason. We took it to get replaced at Safelite on 4/13/22 and one of their techs asked if we knew what caused the glass to break and we told him we had no idea. We told him it just broke out of nowhere from some strange reason, and he told us that it looks like the window breaking was caused by the overheating of the rear defroster and that it was a common issue with 2009 4runners. We were in shock to find this out and are grateful that our son or dog was not in the back seat when this happened. I found out online that Toyota issued a recall for this issue (Warranty Program ZG7) and I spoke with a Toyota customer service rep to see if we could be reimbursed the $100 we paid out of pocket for this manufacturer's defect and they said the warranty program ended in 2018 so they couldn't help us. We were very disappointed to be told this because this is obviously still happening with these 4runners and it's a major safety issue as well.

Filed Oct 22, 2021 · Engine · CA

Engine, no sign of overheating ... Overheated within 3 months of ownership on my way to work with my wife's Conclude the headgaskets were blown. Toyota doesn't acknowledge recall. . Plus send a recall for v6 4runners headgaskets

Filed Apr 15, 2021 · Seats · 88,000 miles · TX · 1 injury

I turned in the ignition and wasn't even around the block from my home, when I noticed my seat overheating along with a strong burning electrical/wire smell. The heat was hotter than the highest setting because it was uncomfortable to remain seated. I checked the power switch, which was off, then toggled it anyway to see if it would turn off. I had to pull over as the seat was too hot and feared it injure me and/or would ignite. After turning off the ignition, the heating stopped. However, I got back in and started to drive, it heated up again. I returned home to look under the seat but didn't see anything unusual, except for the strong burning wires smell. Also, my skin was red with a lingering sting in two areas where the heat was more intense. I conducted on online search about the problem and discovered others experienced the abrupt overheating seats.

Filed Jan 15, 2021 · Electrical, Visibility · 66,300 miles · SC

2006 4runner rear glass exploded/shattered after using defrost - was denied reimbursement despite this being a known issue and faulty defrost connector. After dropping my 5 year old son off for school on 1/15/2021, I pulled up to a stop sign and heard a loud crash from the back of the car. I looked in the rear view mirror and the back glass had completely shattered and pieces were coming off into the back seat. Nothing had hit the window from the inside or outside - this happened spontaneously. Right before this happened, I had the rear defrost on for approximately 10 minutes to clear the rear glass while driving. The defrost was off when the glass exploded. I contacted my local toyota dealership who informed me that this was a known issue but that the extended warranty coverage for this had ended on april 30, 2018.toyota released a tsb (technical service bulletin) and offered an extended warranty and free replacement for vehicle owners who experienced this problem starting in 2017 but is since expired. The connector for the defrost located in the rear glass is found to be faulty and can short out or overheat, causing the glass to shatter. Being that this is a major safety concern and thankfully my 5 year old son wasn't in the backseat at the time, avoiding injury from the glass, I decided to contact toyota customer experience. A case was opened, however, they wouldn't offer any compensation or assistance with getting the glass replaced. We are without a vehicle until this can be repaired and I am now forced to pay for it on my own since toyota isn't agreeing to help at all.

Filed Dec 3, 2019 · Electrical · 2 miles · TX

Rear hatch window shattered due to overheating of defroster. Overheated while in motion. Shattered after parked.

Filed Mar 11, 2017 · 135,880 miles · OR

Driving to work on 3-6-17. It was 34 f at 8:15 am. Turned on the rear window defroster about one mile from home. Drove another 0.5 miles and stopped at red light. About 15 seconds into the red light my rear window imploded and fell into the rear cargo area. Vehicle was stationary and no other vehicle struck me. Drove back home and cleaned up the glass and saw no evidence of a rock or pellet or bullet with the glass or in the vehicle. Online discussions indicate the rear defroster may have overheated and shattered glass. I have 3 photos on file in computer, but not in correct format. Tried to upload, but was not able to do so.

Filed Dec 27, 2016 · Engine · 155,000 miles · MO

I was driving down the highway after getting off the interstate when my vehicle began to overheat. I luckily noticed and pulled over before incurring more damage and warping the engine head. I have heard multiple times that these 4.0 v6's toyota made have head gasket problems. After getting it towed back to the mechanic on thanksgiving, I was told I had a blown/leaking headgasket. I have never drove this vehicle over 3k rpms and find it ridiculous it would fail under such good condition.

Filed Nov 10, 2016 · Body · 48,000 miles · NC

The hatch latch has melted and presents problems in unlatching. The dealer denies this is a problem. Especially in cooler weather, I am often not able to open the rear hatch. My research indicates that many owners of this model experience the same issues. There is some concern that the cause is faulty wiring that overheats the material. Also, the replacement part is the same as the original; therefore, not resolving this issue. This should be a safety concern and should be remedied by the manufacturer.