Overheat

[Craig0ry]

I'v got a problem with my 91 xj overheating just from driving around town and even on the highway, whats usually the problem?

[Davisrats]

could be lots of things. I would start with a flush and a new thermostat.

look carefully and the cores of the radiator, if they are plugged get a radiator.

Does the manual fan work? once the engine is worn turn off the jeep and try to turn the fan by hand it should have some resistance. Is there oil leaking from the fan clutch? Does the fan have the shroud?
does the electric fan come on? When?
Does it run good? Lean will make it heat up.
Ron

[Craig0ry]

The electric fan kicks on sometimes but not when its needed, iam planning to flush the radiator and get a new thermostat hope it will help iam on kindof a tight budget right now

[Nate]

Same problem here....

This is what you have to do......

1. go to your local radiator shop and do an "open system" conversion....cost me $110.00. Use your stock radiator and just have them weld a filler neck on it....no need to get the "trick" radiators. then buy a universal overflow tank from any autoparts store and have them install that. If you want a heater still you can get a heater valve from a newer XJ (i think 93) otherwise just bypass the heater

2. get an Aux elect fan from a newer XJ ( the ones with curved blades)

3. 195 degree thermostat

4. New fan shroud

5. install an adjustable thermostat switch for the new fan

dont "flush" your radiator.....get it roded out and have your block pressure flushed.

all this fixed my problem!

[Navy-Jeepster]

Also, take a look at your catyletic convertor.
My dad had one go bad, that was causing too much back pressure, and causing his XJ to overheat.
All of the other things had been tried, and then a guy happened to be under the jeep, and noticed the cat was bad.
Once that was taken out, and a straight pipe put on, the overheating stopped.

He did not worry about replacing the cat. He was in a state that did not have emmisions testing.

Navy-Jeepster