88' overheet jeep

kay, well i know there are lots of posts on here about overheating, but im to lazy to search for one that relates. well my 88 cherokee was overheating, so i changed the 'stat, waterpump, and the rad, and well its still overheating.

so can anyone help me by telling me what else could cause this.
The jeep is 6 cyl. 4.0, with a closed system

Usually, I tell lazy people to F O, but since you are honest about your motives, here goes.........

(This is from another forum, but very useful)

Ok...there seem to be too many threads with "my xj is overheating" or "yet another overheating thread" or "it only overheats when..." and I am going to try to answer them all and maybe we can get this to become a sticky or maybe posted somewhere.

All cherokees from the factory have a cooling system which is designed to remove heat from the engine and transfer it away. Coolant being pumped by a water pump flows through cooling jackets/passages in the head and block of the engine. It flows around exhaust and intake ports and around the cylinders. From there it goes to the radiator which had hundreds of small fins to increase surface area and that allows as much air as possible to take heat away from the coolant and the cycle repeats istelf over and over.

Chrysler opted for a mechanical clutch style cooling fan to draw air over the radiator to cool at idle and slow speeds. Some models depending on options also have an electric fan for optional A/C or towing package which turns on with a/c (on 2000 and 2001 xjs it turns on with a/c only when pressure in the lines goes past 300 psi) or when coolant temperature exceeds between 218-224 degrees F.

When working correctly and all parts are maintained, this setup works great.

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


If your cherokee overheats on the highway 240+F:

Clogged passages
Stuck closed thermostat
Towing a heavy load up a grade on a hot day w or w/o ac on (temp. overheat)
contaminated coolant
bad waterpump
clogged radiator fins
blocked airflow
brakes sticking/ebrake on

If you overheat on the highway and NOT at slower speeds / idle:

partial blocked passages not flowing enough for highway engine demand but flows enough at idle.
Radiator blocked or fins clogged for same reason above
Brakes sticking
Overloading


Also, xj's have tight engine compartments and they will run 220ish in the summer with a/c on or off and that is NORMAL for xj's. Other vehicles have different coolant temps that they are designed to run well at so dont do too much comparing such as " my Taco runs 210 even though I beat it half way to hell) Thats great...I only like taco from taco bell and the one she gives me...but anyway

Another thing to note...fan clutches run about 40bux new depending where you go. With personal issues there is no TRUE way to test a clutch because they fail soo many ways (trust me). Next time your engine is getting very hot, open the hood and feel the air the fan is pulling...rev er up some and if its not hurricane force, then replace that clutch. With the new body style xj's they upgraded the E-fan to a higher flow rate...so that might be an option for upgrades.
Please add on if you have anything extra.

ok what if the jeep has pretty much no heat inside when i turn on thr heat full blast

You have air in the system and have to burp it.

Yup! I would agree with Saudade, I think that you have air in the system, the one way I have found to"burp" the systemis to remove the uppers rad hose from the T-stat housing, pour your coolant into the upper rad hose, this will force any air in the engine block out throught the T-stat houing. Once you get a steady flow of coolant reconnect hose, fill coolant to proper level and run engine. Might try leaving your cap off for a couple minutes to get and air out that might still be there, then cap it and let the system pressurize. If it still heats up and you aren't getting any heat from the heater, you might have a problem withthe coolant passages being clogged and will have to take it to a professional to ge the system flushed( my 00 XJ had this problem) Also, DON"T add regular tap water to the coolant! This raises problems, use the 50/50 mix that they sell. I use Prestone, but what ever you use should be fine. Also, look for leaks around the bell houing, My 8 had a heating problem, ened up being a leaky freeze plug on the backside of the engine block. Hope this helps.

i haved filled my 89 with coolant and did not "burp" the system. Some people say to take out the temp sensor but it is very low on the engine. I have a hanyes manual and the factory shop manual and either one has any mention about "burping" the system. Does it really make any difference????

could my heater core be fucked, and be blocking circulation.

89ltd: "burping" by any method merely means removing any entrapped air in the system. I never bother removing the temp sensor. Instead I get mine hot with the heater on at fast idle, which generally gets the air into the coolant bottle. Sometimes, I just drive around town on short errands. Once cooled, I top off the bottle and repeat as needed until the bottle remains full (to the full mark that is).

I learned about this the "hard way". My coolant bottle burst one day and I replaced it and refilled the system. After that, my XJ would overheat at idle but not while moving. It would also not overheat with the A/C running. This was due to the elec fan not coming on when the A/C was off. Once I stated moving, the higher engine rpms got enough coolant flowing to cool things off a bit. I thought the elec fan sensor was bad and removed it to replace it. I placed a pan underneath to catch the coolant while I tried to make a quick swap. To my surprise, no coolant came out of the fitting when I removed the sensor. I replaced the old sensor, and fiddled with the large hoses until I saw a big air bubble enter the bottle (actually, I saw all the coolant in it disappear). I topped it off (repeated this several times) and suddenly my fan started coming back on.

As posted earlier by MagicRat, overheating can be caused by many things. The symptoms should dictate the troubleshooting one does to determine the cause. Lazyboy will need to get off his butt and go check a few more things.

Thanks, just wandered if I should do somethiing to mine. It runs at around 100 deg. cel. or just under, its half way on my temp gauge.

well i did do some checking, and i noticed that when the jeep is running hot, almost overheating in the red the upper rad hose on the passenger side and the side of the rad are really hot, but the drivers side lower rad hose and that side of the rad are pretty much cold still, so does thios mean that i have a clog somewhere????

Are you sure you routed the belt properly?

http://www1.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/15/16/b1/0900823d801516b1.jsp

Just an observation. I've been on this forum for about 6 months now and I beleive this is the first time I've seen someone use that kind of language.

Anyway. The upper hose could be hot from steam, not coolant. I would get some clear tubing and put it in place of the heater hose coming from the t-stat. If you don't see flowing coolant with the heater on, then you need to track down why.

I didn't read this whole forum so im not sure what exactly is happening but my cherokee was overheating too, not all the way just to about half way or slightly above. but newayz i installed an auxilry fan that u can turn on by a switch in the console and it comes on automatically when temps get to high. After i did this it really hasn't over heated except on some rare occcassions that im either racing or running it to hard in the trail.