99 taurus overheating

[blkmonday]

ok heres the scenario, my father has a 99 taurus wagon with 115k on it...recently the car overheated to what looked and acted like a bad coolant tank cap. it kept coming loose and losing pressure causing it to overheat. well i replace the cap and drove the car to work today only to have it overheat on me again. it seemed fine on the highway but after getting on the main roads it was boiling over again and steam was coming out of the pressure cap. the car has always had the typical taurus no heat problem. it has had the water pump replaced and a few lines and a thermostat replaced. i did howerver replace the coolant with regular green anti freeze 50/50 mix (im old school and not sold on the other stuff)but this has worked fine for over a year now since the pump was replaced (the old pump propeller looked like a saw blade it was so damaged). there are no visible leaks in the system and the engine doesnt pass white smoke so i dont think its a head gasket. any clues where to start from here? oh yea the electric fan runs fine too.

[reekor]

The car should have a plastic air dam under the rad support, sometimes people break them off by pully up over parking blocks, see if it's still in place. If that is okay and in place, your fan might not be triggering at the right heat range. Other then that the new thermostat might be bad or installed upsidedown.

Originally Posted by blkmonday

ok heres the scenario, my father has a 99 taurus wagon with 115k on it...recently the car overheated to what looked and acted like a bad coolant tank cap. it kept coming loose and losing pressure causing it to overheat. well i replace the cap and drove the car to work today only to have it overheat on me again. it seemed fine on the highway but after getting on the main roads it was boiling over again and steam was coming out of the pressure cap. the car has always had the typical taurus no heat problem. it has had the water pump replaced and a few lines and a thermostat replaced. i did howerver replace the coolant with regular green anti freeze 50/50 mix (im old school and not sold on the other stuff)but this has worked fine for over a year now since the pump was replaced (the old pump propeller looked like a saw blade it was so damaged). there are no visible leaks in the system and the engine doesnt pass white smoke so i dont think its a head gasket. any clues where to start from here? oh yea the electric fan runs fine too.

[TaurusKing]

What is the "typical" Taurus no-heat problem??? All of mine have had hot hot hot and cold cold cold climate control... most likely the core is partially plugged, if not then a blend door issue,, flush the entire system ,pay very close attention to the bypass hose setup behind the engine, cause of many issues with cooling... flush the core separately,, stop overheating the engine, you'll trash it,, gauge runs up, get out and walk.. put a new thermo in for the h of it... also use the green only, nothing else, no dexcool whatever you do.. if the fan turns on and the temp gauge drops, how much depending on your current running conditons, it's fine..