There are 2 owner-reported engine complaints for the 2012 Toyota 4Runnerin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
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.
TL* THE CONTACT OWNS A 2012 TOYOTA 4RUNNER. THE CONTACT STATED THAT WHILE DRIVING AT AN UNKNOWN SPEED, AN ABNORMAL SMELL EMITTED INTO THE VEHICLE AND IT BECAME EXTREMELY HOT AROUND HIS FEET. THE CONTACT STATED THAT THE VEHICLE MADE A LOUD POP NOISE AND AFTER MERGING TO THE SIDE OF THE ROAD HE NOTICED FLAMES COMING FROM THE FRONT PASSENGER SIDE OF THE VEHICLE. THE VEHICLE WAS TOWED TO A DEALER. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 49,000.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026