1975 Jeep Cherokee - Always runs hot

I have a 1950 Willys Jeepster that has a 1975 Mustang 302 V8 and it is always running hot. I put a
new bigger radiator in and it still runs hot. Short trips even make it get up to 200 degrees! Someone said to remove the thermostat since I live in Florida and don’t need to worry about cold weather. I read some older comments on this subject and it is not clear to me if I should consider removing the thermostat or not. Thanks, Eileen

What kind of fan are you using? If electric, is it switching on?

Also is the radiator surface area large enough? I am thinking that the physical size of a Mustang rad is larger than a Willys Jeepster. Could you check surface area measurements? If you have an electric fan do you have the wiring hooked up to provide the correct airflow direction?

Is the thermostat opening ?

What is the temp difference between upper and lower radiator hose ?

Are you sure it’s running hot ?

Do you have the correct temp sending unit for the gauge you are using ?

200 deg F coolant temp isn’t overheating, within normal operating range. My truck of similar vintage is also a 302, tends to run on the warm side in stop and go driving. Just comes with the territory for that era’s technology. Removing the thermostat won’t be effective, forget that idea. One way that will work to moderate the temps during stop and go driving, replace the passive belt driven fan w/an electric cooling fan. This will likely require replacing the alternator as well.

Asking a cooling system specialty shop to access the situation could do the trick too. Perhaps all that’s needed is to flush the radiator of years of accumulated debris.


Since this is a custom install, I have to ask - are you using a fan shroud and is it positioned right? Friend of mine put a Ford 302 into a Jeep CJ years ago. Didn’t use a fan shroud and the fan wouldn’t pull enough air through the radiator at low speeds so it would heat up around town. Temp was fine on the highway, though.

As for the thermostat, I really don’t think removing it is going to correct your problem, unless it’s sticking closed. You could remove it and see as a test. I’ve heard differing opinions on running without a thermostat long term. I don’t think it would cause issues on a 1975 302 in FL in the summer. Might be hard on the oil in the winter, though. It should be able to run without overheating with the thermostat in place though, so I think something else is going on.


Keep in mind all that air that must come through the radiator must leave somehow. You filled a lot of that airflow space with engine! Louvers in the hood would help.


Looks like another one and done post, no reply to the questions any of us have asked.