i have 89 cherokee 4.0 over heating ,new tstat,heater core water pump, hoses, radiator, clutch fan, electric fan. no lose of power no smoke no water in oil gots me stumped any info would be helpful thanks

When you say overheating, what do you mean? Is it pegging the temp gauge, or is it puking coolant?

puking the coolant

Bud, I couldn't help but notice you didn't mention replacing the radiator cap; I've seen many of them cause an over heat/coolant puke problem. If that doesn't fix it, I'd look for signs of a bad head gaskit. Let it set over night, then pull the spark plugs and check for rust forming on the electrods; any rust forming is a sign of water in that cylinder. I'd also perform a compression check and post the results on here. Another check you can do is take it to a station that does smog testing and have them check the coolant for hydrocarbons. The only way hydrocarbons can get into your coolant is a bad head gasket or a cracked head. Hope this helps.........

Easiest check for compression leak is to park in such a way that the FILLER hole for the coolant is the highest place on the engine.. Then fill it to the brim and start it.
Have a hose handy with a small flow of water going. As the engine runs the level might get a bit lower KEEP IT FULL.. As it runs small bubbles will appear in the coolant if it has a compression leak.. However if the filler hole isn't at the highest point while doing this test you won't see the bubbles.. If these bubbles do appear they positivly come from a compression leak.
I don't know of a cap causing constant overheating in an otherwise good system.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

this jeep has the pressurized tank and i replaced the tank and the cap. so far the jeep shows no signs of a bad head gasket. but that is what i thought it was and took it to shop and they said head gasket was good.

You didn't answer the question.. Does it PUKE or just show hot on the gauge?
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Throw out your old radiator, and replace it with a new one.

BJ his second post was "puking the coolant"

AHHH I stand corrected.. Then the ONLY answer is to do the bubble test as I outlined above.. With all the new parts he has installed either he isn't getting it FULL of coolant when filling or he has a leaky head gasket..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />