HOT blooded XJ

warblade666 · **Posted:** Tue Jun 27, 2006 12:02 am

I have had my XJ since Feb 2005. Last summer it was running a little hot when temps got over 90deg. and very hot when wheelin (at night) even in 70-80deg temps.

I have installed a new water pump, 180 deg thermostat, fan clutch, flushed the cooling system, and now installed a new CSF 3-core HD radiator (it still had the stock 1-core) & trans cooler.

Temps here have hit the 90's last week & low 100's this week. It is still getting to hot, 200+ in town, and still going up. The stock auxil fan doesn't come on till 220deg WOW. I wired it to a switch so I can turn it on & off when I want. After about 20-30 min of driving (even with the electric on) it stll wants to run around 200-210 deg in town & on the freeway.

It stays right at 180-190 deg on just the clutch fan as long as the temps stay under 80 deg. I still have to turn on the electric when I go wheelin, even in 65 deg temps.

It doesn't have a bad headgasket or any cracks. Doesn't use any oil or coolant. No leaks, knocks, rattels, or pings. It has good vacuum & compresion.

ANY ideas?????

I'm at a loss here.

wolfheartak · **Posted:** Tue Jun 27, 2006 2:34 am

4.0's are supposed to run at 210...

-Marisha

JJsTJ · **Posted:** Tue Jun 27, 2006 7:22 am

Yep, 210 is normal for a 4.0L. Mine will run over that pulling hills in the summer but until it hits the red I don't worry.

warblade666 · **Posted:** Tue Jun 27, 2006 12:16 pm

That just seems to hot to me.

Two of my freinds here have Wranglers, One a '92 YJ on 35's he uses a 180 thermostat and never gets past 190 deg even when wheelin in 100 deg temps. The other has a '99 TJ on 31's that runs a 195 thermostat that stays right at 200 deg all the time.

I had heard that XJ's run hot because of there smallish 1 or 2-core stock radiators, but with a new 3-core I was hopeing it stay below 200 deg. Or at least level off at 200 and stop there. I just don't feel comfertable when out on the trails hitting 220-240 deg with both fans running.

Is it the computor that is still trying to "warm up " the engine to 210???

I have seen the Jetchip's modules that come with a 160 deg thermostat. Anyone ever use one ?

JJsTJ · **Posted:** Tue Jun 27, 2006 12:22 pm

JUst because the thermostat opens sooner doesn't mean it will run cooler.
UNless it runs at 230-240 for extended periods or shows other signs of problems, I really wouldn't worry about it. The only thing that might help a little is adding some vents to the back of the hood to allow some hot air to escape. OThers have tried it w/ mixed results.

Guyute1210 · **Posted:** Wed Jun 28, 2006 1:16 pm

JJsKJ wrote:

JUst because the thermostat opens sooner doesn't mean it will run cooler.
UNless it runs at 230-240 for extended periods or shows other signs of problems, I really wouldn't worry about it. The only thing that might help a little is adding some vents to the back of the hood to allow some hot air to escape. OThers have tried it w/ mixed results.

There is a guy over on Erie Jeep People (www.eriejeeppeople.com) that installed louvers <SP> on his XJ. Not only does it look good, he doesnt park it in a garage, adn has had no problems with his temp or issues with water since installing them. Might want to pop over there and inquire with him.

JJsTJ · **Posted:** Wed Jun 28, 2006 4:56 pm

I am familiar, i have a set of hood vents from a Turbo Lebaron sitting in the garage. So far, knock on wood, I do not think it has run hot enough to bother w/ installing them so the project is on hold. I probably will eventually, but I am planing on running a temp probe underhood before and after to see if there is an actual change. Another easy, chepa, quick fix is to just add a small spacer or couple washers between the hood & hinge around the bolts to allow the back of the hood to sit up enough to allow the hot air to escape. I might try that too to see how if it works.

warblade666 · **Posted:** Thu Jun 29, 2006 10:29 pm

Does anyone have any good photos of some dual electric fan setups on Cherokees?

I have been searching the web and only found a few, most were right hand drive, not USA.

It's been a week now that I installed the new 3-core. The temps on the freeway have came back down to where they were before (180-190deg) at 65-70mph. Still jumps to 210-220deg on hills and some times in town.

I tested the electric fan the other day....

It didn't come on till the temp gage went past the last line (240?) before RED 260deg. Had to coast down a long hill to get it back to 210, And the fan shut off well before the temp got down to 210. More like 220-225 deg.
Maybe the gage is wrong. I was told it should come on at 220 and off at 200.

Anyone know were the temp sender is on a '96??

All I can find is the coolent temp senser.

deserthorizons · **Posted:** Mon Jul 03, 2006 7:36 pm

Here is some of the best advice I have ever read on the "other" forum..

it has a few different scenarios on what would cause overheating when..
and a few fixes.. check it out..

http://www.jeepsunlimited.com/forums/sh ... p?t=656646

desertliberty · **Posted:** Wed Jul 12, 2006 12:00 am

Quote:

Here are some reasons your cherokee would overheat (240+f) at idle but not at 30+mph:
Fan clutch worn out
Old coolant
Aux. electric fan not turning on
blocked radiator or coolant passages
Low fluid level
Low engine oil level
Water pump impeller wearing causing low flow at slow speeds
clogged radiator fins or air blockage to radiator
Damaged fan shroud
Retards who upgrade engines and leave stock cooling system

The last line just kills me.

One thing that I didnt see in all these posts is, What year is your XJ? If it is a Pre "91" and has the closed system Check to see if the Stupid plastic cap is not allowing pressure to escape from the Stupid plastic bottle. Ok I am getting off my Stupid soap box now.

Brian

nickmv · **Posted:** Fri Jul 21, 2006 9:57 pm

definitely check the sending unit, although I'm not sure where it is. I had a 95 XJ Country and the temp guage was haywire all the time. 4.0's, which in my opinion were a heck of a lot better than the 3.7 in the KJ, always ran pretty hot.

warblade666 · **Posted:** Sat Jul 22, 2006 3:54 am

It is a '96. It seems to be doing better now. Finaly got all of the air out after the new radiator.

Went wheeling in the sand last Saturday, 90+ deg heat. I kept my auxil fan on with a toggle, and stayed under 200 deg.

Today got up to 113 deg, and I stayed at 190-210 all day running around town without the auxil fan.

HOT blooded XJ

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