I have a 91 escort gt with a 1.8l dohc.
the car over heated about three weeks ago. I replaced the thermostat and the sensor on the thermo housing, now the car almost overheats before the fan kicks in..any adivce?? thanks
But don´t forget the obvious...What temp is the thermostat rated?Alot of shops sell there lowest temps. first Often giving people the minimum requirements when they get low"well won´t that one fit?"yes but what´s the thermostat open at?
I took the thermostat out and it still does it. the ratio is 50-50 antifreeze and water. the thermo was rated at 195
thats what the system calls for at pep boys but lord knows The system has been wrong many o times. I checked mitchell on demand to have the same thing.. Im begining to suspect a faulty
fan. after this Im going to stick with brakes this has been a nightmare.
Im however interested in learning more on the air lock theory..Thanks
sorry forgot to add,
yes the cooling system has been flushed, the top and bottom hoses have been replaced. and the thermo was installed properly. Ive done a pressure test on the radiator cap and it was fine...thanks
Ok, not to insult Kenny in any way, but I hope you didn´t go with his idea about taking the thermostat out. That is a big No No. The thermostat keeps the coolant in the engine log enough for it to absorb all the heat it can, whil at the same time allowing the coolant in the radiator too cool down enough to actualy cool the engine once the thermostat opens. Removing it could cause it to over heat quicker by not allowing the coolant to stay in the radiator long enough to cool down. As far as "Air lock" goes, If you have an air pocket in the engine, then there is essentially a spot that isn´t getting cooled properly since water isn´t touching the part with the air pocket, it can´t absorb the heat. I have read in a number of places as well as done this myself, but if you drill a hole about 1/8 inch round in the flat part of the thermostat this will allow any air to escape while the thermostat is closed, but yet allow enough of a restriction to keep the water in the radiator so it will cool down. Hopefully this helps a little bit.
we used to just run em with the radiator open and when the thermostat opens slowly add mix until it wouldn´t hold more then turn on the heat full blast and maintaun the level it takes alittle while but when you get no more bubbles coming to the radiator cap you know you´ve got em all,you will also be able to observe the fan and take the temp to find out when it turns on.