not sure this goes here but heres the prob. I have a 91 z with a 5.0 tpi and the problem is when I drive it on the highway the temp goes to 220-250 but if I drive in town it stays at 150-200 it does not have any leakes that I can see and does have coolant in it,,,any thoughts

thanks
steve

 

What shape is the drive belt in? May be slipping and not turning water pump properly! Be sure the radiator grille isnt blocked be debris. Is your thermostat good? Is radiator cap holding proper pressure?

 

quick question here, where is the thermostat located?

wait a minute, think I found it, is it the circular thing on the left side of the engine bay, with 3 tubes going into it?

 

Follow the upper radiator hose to the top of the engine. The hose will be clamped to a big metal fitting. It's got two bolts on it. The thermostat is under that. Let the engine cool before you take those bolts loose, and take the radiator cap off just to be sure there's no pressure. Antifreeze is not good for your face, especially at 220 degrees.

 

You will also want to drain your antifreeze down some before pulling the radiator hose off the thermostat housing.

 

You should also check under your car to make sure that you still have your air dam attached.

I think that "generally speaking" if your car overheats at idle then your radiator fans don't work and if it overheats when driving and you've got plenty of coolant and a good water pump it's generally the air dam.

 

Put the damn air dam back on.

 

the damn air dam is on the car,,the belt is ok I was thinking it might be the pump or themostat but coolant is circulating to best of knowledge so I am not sure what it is