[WILSONRIVERFISH]

Jeep drives fine moving but when parked and idiling yesterday the temp went up almost full high temp. I shut it off waited for it to cool down and then thought i would see if driving it helped well it did the temp went down real low and all was fine. Im wondering if the overflow bottle was overfilled? also the top radiator hose was as hard as a rock. Im kind of thinking that the t-stat got stuck closed and help for this newb would be great

[cygnus58]

maybe your electric fan isn't working.
if it seems fine at other than idle, and the ambient temp was in the 90's. it will need the electric fan to work after a few minutes of idle.

[WILSONRIVERFISH]

the fan is turning and doing so fast. It was almost 102 degrees yesterday.

[curtjames37]

Could be the fan clutch on the mech fan.

[rustywrangler]

If the top hose was hard as a rock then you may want to look into a new thermostat. 195* one.

[NYCXJ90]

have you recently added coolant? if so did you burp the system? check to see if your coolant pressure bottle's cap is on tight and not leaking or cracked. any loss of pressure and the closed system is near useless at idle.

just to be clear... the electrical fan (drivers side) is kicking on normally? (usually at around 210-220*) check it with the AC/ Defroster off. If it's not coming on it could be the temp sensor in the radiator. There's a way to test the fan clutch on the mechanical fan, run a search, should come up.

if you determine both fans are functioning correctly then you have a flow problem.

check for weeping/moisture around the bottom of the waterpump, if it's leaky you need a new pump and might as well throw in a new t-stat.

[pgdyk]

Could also be your guage, if it went to full high temp, coolant would be overboard, right?

[WILSONRIVERFISH]

ok I didnt know about the second fan on drivers side! Also im thinking there is pressure being released

[curtjames37]

If it's not holding pressure then that is most likely your problem. Closely inspect the cap/pressure bottle for cracks or leaks and replace if necessary.

You can also try burping the system:

BURPING the COOLING SYSTEM
http://www.lunghd.com/Tech_Articles/Cooling/BurpAirMod.htm

[WILSONRIVERFISH]

yeah coolant was spilling out! It was hot but went down real fast after just a little driving and some lead foot action. It was only idiling maybe 5-10 minutes. I will inspect the cap and hoses, replace the t-stat, water pump and maybe even replace the top and bottom radiator hose. Or should I move to the open system?

[pgdyk]

Well before you go spend a fortune and slap on a bunch of parts, try and find the root of the problem. Test the electric fan like stated before, If you are sitting there idleing and it is overheating, it may be an airflow problem, your radiator could be clogged with debris, mud, leaves, grease, etc, hose it down gently. Also, do you have a fan shroud? The plastic cover that protects yourself from losing a hand to the mech. fan, it also directs air through the radiator, instead of around it.

[WILSONRIVERFISH]

nope the fan shroud is gone!

If possible and if you know of a link to but a new one give it up otherwise ill search around for a junkyard that has one.;

[pgdyk]

My girlfriends 89 xj overheats while idleing for even just a minute at the drive-through without a shroud, its impossible to take out in rush-hour. It's fine and dandy on the freeway. I would look around a few junkyards, if no luck, you may have some luck with a shroud from another jeep, maybe a cj or something, maybe even a ford? Ive had to go to the dealership to get a shroud. Anyway, thats probably the problem, along with your electric fan not coming on at high temp, or it doesnt move enough air to cool everything down fast enough. I'd get this fixed, especially if you have an automatic, it is cooled by the radiator.

[_Cody_]

i dont have an electric fan on the drivers side :O
is that bad? I think the guy before me took some a/c stuff from under the hood, and could have taken that.

[AZ Jeff]

Originally Posted by _Cody_

i dont have an electric fan on the drivers side :O
is that bad? I think the guy before me took some a/c stuff from under the hood, and could have taken that.

Yes, that's bad. ALL 4.0 XJ's NEED the electric fan to supplement the mechanical fan when driving in hot weather and/or stop and go conditions.

Get a replacement in ASAP.