My 94 xj 4.0 is overheating. I have a new water pump (ive tried a even different one), new temp sensor, new temp switch for gauge, 3 electric fans, all turn on, mech fan has a brand new clutch, new head gasket, has 50 miles on it (thought that was the culprit), head had no cracks or warped, new radiator, i am not running a tstat at all, because itll let me drive from point A to B without it overheating to fast, and i have to keep the heat on high to be able tp drive a little bit longer. When i have a tstat in it, i havent been able to get one to open, its very strange, so i just took it out, and still overheats. I dont know what else to do

 

You have a mechanical fan and 3 electric fans? How'd you fit all that in there?

Do you have a fan shroud in place on your mechanical fan? Are you running 50/50 coolant/water mixture? Have you verified the temperature with an infrared heat gun and not going strictly off the gauge?

 

Jeez and I just read that you can't get a tstat to open... Where are you buying them from? Sounds like you've been getting defective tstats. Try getting one from the dealership

And when you say you are overheating, is the coolant actually boiling over into the overflow bottle? The XJ gauges arent known to be 100% accurate all the time. You want to verify the temperatures

 

Okay so i just bypassed the heater core, and put a new rad cap on, and still overheating. Im on the side of the rd right now. Fan shroud yes. No i have not physically used a temp on the water, i know its HOT to the touch tho

 

And yes its going to the overflow

 

And its about 60% water, 40% antifreeze

 

It sounds like your systems not pressuring up. When you did the head gasket and Rad , have you pressure tested the system. My 4.0l is 18 psi

 

Well it keeps pressure, i left my jeep for 2-3 hours and the hose was still very tight until i took the cap off. But now either the motor is locked up or my starter is out. Fingers crossed for the starter

 

I would think with a properly functioning radiator cap and cooling off for 2-3 hours, the hoses would be soft.

 

Well its a brand new rad cap, 13psi

 

Have you ver tried flushing the block? It could be so gunked up in there that even having a new water pump and whatnot it still can't flow good from the gunk. Have you ever used radiator leak stop stuff? I know from personal experience that that stuff stays in the system forever unless you flush it real well. Which is what I did and now I never overheat.
Is your tranny overheating causing the heat exchanger in the rad to heat up the water?

 

Well i put all new fluid and filter in the trans, but i guess its possible, and i recently had the engine completely out about a week or so ago, and brand new radiator, so no i never used stop leak