Tahoe4runner
New member
Toyota 4runner 2002 SR5 - After a recent trip to San Francisco from Lake Tahoe, I ran for 4 hours at 70mph with no problems. Upon hitting heavy traffic it started to overheat and VSC and TRAC and check engine light came on. After picking up speed again it cooled down. Coolant level is okay but looking rusty and in need of a change / flush. Radiator has been replaced 2010 due to a crash.
My thoughts on diagnosis, If this were a water pump or thermostat issue then this would result in consistant overheating irrelevant of driving speeds. However this only seems to be happening around town driving conditions.
This leads me to think it could be the cooling fan, Im aware of hard wiring it to the battery to check the function of the fan but also is it possible / common for the relay's to fail telling the fan when to engage ? Is there a temperature sensor on the engine which sends the signal for the fan to engage, If so should I try this before the relays ?
Worst fear of it been the head gasket, but want to eliminate these things first.
Thanks.
My thoughts on diagnosis, If this were a water pump or thermostat issue then this would result in consistant overheating irrelevant of driving speeds. However this only seems to be happening around town driving conditions.
This leads me to think it could be the cooling fan, Im aware of hard wiring it to the battery to check the function of the fan but also is it possible / common for the relay's to fail telling the fan when to engage ? Is there a temperature sensor on the engine which sends the signal for the fan to engage, If so should I try this before the relays ?
Worst fear of it been the head gasket, but want to eliminate these things first.
Thanks.
