I know its a jeep thing to have them fun hot but im just getting tired of it and to darn hot in the summer! I have a 1990 xj, 4.0. I replaced the thermostate, coolant resiviour, thermostate housing but cant get it to stay cool. My next thinking is the radiator. I've looked up the factory replacement but am also thinking about a 2 or 3 core aftermarket one. Any thoughts or suggestions?

 

Welcome to CF from Tj... Try burping the radiator cause you may have an air pocket in there...Tj
http://www.lunghd.com/Tech_Articles/...BurpAirMod.htm

 

Get the "open" radiator system for a 94+ cherokee... It works great!! I have NEVER overheated under any condition since I swapped out the old crappy closed bottle system. Parts you will need... 94+ Radiator & Cap, Heater Control Switch, Coolant recovery Bottle, 5/8 heater hose.. The only thing you will lack is the coolant temp. sensor for the fan that connects on the bottom of the Radiator. Mine runs below normal operating temperature, even in the summer. I wired my fan with a manual override switch, but since it cools so dang effectively, I never have used it....

 

So putting the 94 sytstem on the 90 works? I understand Ill have to wire up an override for the fan and thats not a problem. How was putting the 94 system in? Does it mostly just fall into the old systems place or do you have to fab some stuff. Covering all bases on this one.

 

NO FABBING REQUIRED!!


Only difference is the Pressure bottle goes "bye Bye' and so do your broken bottle/pressure & coolant loss problems..... That tangle of hoses is gone.... I put the overflow tank I got back where the pressure bottle was, but I needed to buy a longer hose for it to reach... The only difference in the radiators is 1) the new one has the radiator cap and 2) there is no connection for the fan switch temp sensor. but they are the same dimension.

You will need: I just used 1994 for the year.
*Radiator
*Radiator Cap
*Heater control valve
*Coolant overflow bottle (I used the one from Advance Auto Parts {the smaller one fits nicely where the pressure bottle was})
*Long piece of hose 7' +/- for coolant bottle. not sure of size...
*Heater hoses (reuse your old ones if you are careful)
get some 5/8 hose anyhow...... You'll prob have to cut the hoses off of the heater core in/out lines.....
*Clamps.

Usually not a bad Idea to do a full flush and replace your T-stat since the system is all apart anyhow....... Of course check your upper/lower hoses and replace if needed, and make sure your coolant/mixture is at least 50/50 and no less than 70/30. Coolant/Water. Water Corrodes, Use distilled or just refill it with a good 50/50 and be done with it!

Good luck.....


Halfway decent write up for the Rad swap.... http://www.jeepforum.com/forum/f11/p...estion-834546/ Not to bad, you can get the gist from it.....


Override switch link.... http://www.olypen.com/craigh/auxfan.htm
and if you go to the "tech" page {at bottom} on his site there is other neat tricks, mods you can make and helpful writeups and such there too....

 

I'd almost bet that replacing the possibly 20+ year old rad, water pump and fan clutch (with what u have already replaced), it would cool like new again. Didn't XJs run cool when they were new, like most new vehicles?????

 

i took the t-stat out of mine, but keep in mind that i live in florida so i don't need that help with warm up. also when i had over heating issues in my 89 the coolant bottle would look like its about to explode , turns out the problem was that the hoses were connected to the wrong places on the heater core/heater valve/ pressure bottle/water pump/ t-stat housing, so check your hose routing first cause it's free.

 

look in fabrication under renix radiator upgrade standard shift

 

you have to rubber hose the tranny lines if yours is automatic

 

forget what i said, it got freaking cold down here all of a sudden and my jeep took forever to warm up. that is after i fixed the main source of my overheating problems. the t-stat is now back in.

 

1. Consider converting to an open system as mentioned.

2. Your radiator and your water pump are DEFINITELY still suspects here. Swapping both of them out to new is not a bad idea. These parts are not that expensive if you can do the work yourself. Do yourself a favor and do both while you have everything torn apart...

 

@ Radar: Where in Florida??? Did I ask this before?? I'm in St. Auggie.....

Bryan.