So I have a heating problem with my 92 xj only when I am running four wheel drive I have replaced the radiator and water pump and thermostat and all the sensors and now every time I am in four wheel drive the temperature starts to heat up real fast and ain't sure what is causing this any help would be great.

 

I'm guessing you're going slower than hiway speed when you're in 4 wheel drive and get the heating up issue, maybe crawling along? How much does it heat up? Over 220? Coolant overflowing? At slower speeds there's less air flow thru the radiator and that's where your clutch fan comes in to draw more air thru it. I've heard of people using a rolled up newspaper to try to slow down the fan (at idle and very carefully, i'd imagine) I don't think you should be able to slow it down much if it's working properly, but there's probably a better safer method to check it. If your jeep has an aux. radiator fan, it should come on when the temp gets above 220 or some such number.

 

Yea it only does it when I am crawling and I have a clutch fan and aux fan I was going to 2 core radiator and get rid of the 1 core but didn't know if that would fix the problem but I will look in to the clutch fan also thank you for the info

 

And it is almost to 250 when heating but it is not going into the over flow ether so could the radiator cap be bad?