1995 taurus overheating

[audi4k]

how are you all doing?

I have a question that is probably pretty common but i had no luck searching the forums for an answer. I have a 95 taurus 3.0 liter vin code "U" that is overheating at stops and low speeds. Otherwise it runs well below normal operating temps. at highway speeds. I know i have a small leak in my radiator end tank, but i often check the coolant level to make sure that it doesn't run low. I have replaced the water pump, thermostat and have done a drain and fill to date. I do get some squeaking from the serpentine belt. My thoughts are that i have a bad tensioner pulley, my cooling system is under-pressurized and is causing fluctuation in the coolant temps., the thermostat is set to open at the wrong temp (or is faulty all together), or i have air pockets in the engine block. I'm at a loss at this point, and am trying to avoid buying and installing a radiator right now... but if it is what i have to do, then so be it. Any help would be greatly appreciated.

Thank you,

Andy

[audi4k]

2 bad thermostats in a row..... go figure! running it without a thermostat for the time being.

[awlkrsn]

It could be that you need to purge the air from the system , could be an air pocket or have it presure tested for head gaskit leakage . Don't run it without a thermostat NOT GOOD will cause an air turbulance which is like trying to put out a fire by pouring gasoline on it . My 2cents

[stangluver]

Absolutely not a good idea to run it without a thermostat. Its not uncommon to get bad,new stats. They are mass produced. My experience is 1,purge the system, 2 the radiators are way underrated and should be replaced with larger capacity after-market ones. Just my opinion

[jonmark1985]

Originally Posted by audi4k

2 bad thermostats in a row..... go figure! running it without a thermostat for the time being.

heat the thermostats in a pot of hot water on your stove, use a thermometer to verify the temperature at which the thermostats are opening.

Alot of circle track guys remove the guts from the thermostat.

Personally it doesn't bother me to run without a thermostat. Some people claim that the coolant moves to fast and doesn't absorb enough heat in the engine. Everyone has their own ideas. I'm just not on board with this one.

[wiley692]

the overheating at stop and low speeds could be the fan not running. find and disconnect the temperature sensor for the PCM. on my 3.8L it is on the rear center of the engine near the upper radiator hose. the fan should come on low for a few seconds then speed up to high speed. this checks to see if the the computer is capable of running the fan or not. by unhooking the sensor the computer goes into a high fan default mode. if it doesn't either the fan is bad, or the relay module. if it does come on at both speeds plug the sensor back in and let the engine warm up and see if it ever comes on on its own. if not it is probably the sensor. mine won't come on until it gets to the 2/3 position but i am having different issues with mine. hope that helps BTW, don't LEAVE the sensor unplugged. that is just for testing and emergency purposes and will kill the gas mileage

[wiley692]

One more thing, there should be a circuit breaker between the fan and the relay module. don't bypass that breaker. if your fan is bad it will overload the relay module and burn it up. i found that out the hard way!