1993 Overheating

[Grezo]

For those familiar with my car, mainly Rod, you know it has its good times and bad. Now we are having an overheating issue. We have removed the thermostat and the car is still overheating.

The Car starts to over heat as soon as the car slows, or when we are sitting still. We have checked the Fan, its running fine. Our thoughts are it is the water pump, but the freeze plug has not blown out, which my uncle says will break when the water pump is not working properly. My question is, can the water pump be broken and the freeze plug remain intact?

[shorod]

Can't say that I've ever heard of a faulty water pump causing a freeze plug to pop out. In fact, the only ones that I've experienced to fail in my admittedly short automotive career were due to corrosion and started leaking. In the Taurus the water pumps tent to corrode themselves, the impeller starts to essentially dissolve. There have also been some folks on this forum that have also installed new water pumps only to find the impeller is backward and therefore they don't pump properly.

Does the car truly overheat (boils over) or the temp gauge just gets well above the "normal" range? When you confirmed the fan runs, was that with the A/C or defroster on, or with the climate control turned off? There are several settings in the HVAC system that will request the A/C and therefore enable the radiator/condensor cooling fan.

Since you had the system open to remove the thermostat you could currently have air trapped in the cooling system causing a "false" reading of the Engine Coolant Temperature (ECT) sensor as it tries to read the temperature of the air in the system rather than being immersed in coolant.

You might also check the integrity of the pressure cap to see if it is maintaining the proper cooling system pressure.

-Rod