Two problems related to engine exhaust system have been reported for the 2005 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Toyota 4Runner based on all problems reported for the 2005 4Runner.
Engine loosing coolant. Vehicle brought to an independent service station which determined that the vehicle has head gasket failure. 3. 0 v6 engine. Coolant being lost through exhaust system with usual symptoms of this problem. Vehicle has just over 100k miles. Appears this is around the mileage that gasket failures occur. This is a problem for which Toyota previously identified a limited number of vehicles for a recall. However in reviewing this website it appears the problem was ongoing beyond the vehicles identified. Although this is an older vehicle, if it had been recalled and fixed I most likely would not have had this problem. Toyota notified but is denying any responsibility for faulty gaskets beyond identified vehicles.
If the back window is open and the air handler is on recurculate exhaust gets pulled into the car.