SERIOUS HELP NEEDED, : / please guys im lost

alright... well its to the point where im almost literally ready to park my jeep and throw the keys in to the ocean.... im soooo sick of this problem im having. ill start from the beginning.

about 6 months ago i was at work and i replaced my thermastat. i then drained and flushed my cooling system. i put the new antifreeze/water in the tank and it was good from there. then GRADUALLY. when i would come to red lights/ or go through the drivethrough for food. my temperature would slowly pass 210 degrees. i would look down and it would be a SLIGHT bit hotter. the longer i wait. the hotter it gets, but when i put it in neutral and rev the engine for about a minute...the temp goes down. also when i start moving the temp goes down. currently. its gotten to the point where it is no longer gradual. when i come to a red light it overheats ALOT faster than it used to. but when i drive its fine again. im completely stuck and dontk now what to do. i KNOW its not my thermastat because i changed it roughly about 2 months ago. my water pump isnt leaking and my fans are both working. the only thing i can possibly think of it being is my radiator. i was thinking it could be all clogged up and may be time for a new one ? does this sound like a logical diognosis ? im sorry to be asking soo much guys its just i dont know what else to do.
my jeep is a 1989 jeep cherokee pioneer. i have a 6.5 lift / and no engine upgrades.
i have new battery/starter/ all wires/ i hope this is enough info thanks for your time guys and i hope you can help me


thank you... matt

you might want to check that your clutch fan is actually working correctly, and maybe get rad. flushed. Are you using the shroud for the mech.fan? That not being on mine caused alot of my overheating problems.

yes the shroud is on the fan. they are also both working correctly. ive already checked them. they both turn on and off when needed.

You are over due on a radiator replacement.No need to switch to the open system,just replace the radiator.
Wayne

you say that "both turn on when needed", are you running dual elec. fans?
If they are working right, then I would suggest that you get the rad. flushed.

If you have a clutch fan, then I would first suspect that. From the posts it is unclear as to whether you have a clutch fan or not. If you do, take some safety wire and wire the fan/clutch so the clutch is bypassed and the fan always works. If that doesn't fix the overheating at an idle, I would take a different tact. I would pull the plugs and do a plug check. You may have a signifiant vacuum leak, causing it to run hot at an idle. Surprisingly this is fairly common. A quick check has to do with your A/C and defrosters. Does your heater or A/C only put air out the defroster vents. If so, you most likely have a vacuum leak. A vacuum leak can also show up as a high idle.

Since your temps are fine at any driving speed, that tells me that the radiator is doing fine, you just aren't getting enough air flow or you are running lean at an idle. If it would overheat pulling a long hard hill at speed, I would say the radiator is clogged.

Make sure that there is no air in the cooling system and is completely full in the radiator and about half full in the overflow. I would also go for a new radiator but check other options first that could be the problem. Did you replace any hoses when you flushed your cooling system? If you replaced the lower hose with a hose that doesn't have the metal coil inside it might be calapsing on you and causing your problem.

Kim

its an automatic so i dont have a clutch fan correct ???

i have 1 smaller electric fan and then one big metal one. so i still dont know what to do. old_man said that its probly not my rad but some other people say i should change it.

another thing. how do i know if there is NO air in my system ??? i mean the overflow tank is about half full, but how do i nkow if the radiator is full ???

Thats how mine started....gradually...then WHAMO couldn't cool it down.....bad radiator, got one from www.radiatorbarn.com (I think). short money, under $110 and delivered the next day, less than 24 hrs. Good luck.

The big metal fan is the mech. one that "old man" is talking about using the wire to "lock-out" the clutch on. As for how to make sure there is no air in the system, that I am not sure about, because all of my stuff gets the "new" style rad. within a week of becoming mine, along with brakes, etc..
The radiator gets changed becuase everyone of these things that I get is "all original" under the hood, and usally the rads. are stopped up.
Ren

Having a clutch fan has absolutely nothing to do with having an automatic. The metal fan you have is driven by the serpentine belt. Between the fan and the pulley that the belt turns is a finned aluminum mechanism about 8" in diameter and about an inch or so thick. This is the fan clutch. They routinely cause problems like you describe. My troubleshooting proceedure was to wire the fan such that the fan clutch can never release. It will make a lot of noise at speed but it will make the fan spin at an idle, like it should when it is hot.

Bottom line is that the fan clutch is most likely shot. An engine generates more heat driving under load than at an idle. The reason you don't boil over while driving is that the ram air effect is blowing air through the radiator. On the highway, you don't even need a fan at all. If the radiator is plugged, no matter how much air gets blown through the radiator, you will overheat, but in your case, you say at any driving speed at all, you are not having overheating problems. That tells me that the fan clutch is shot, plain and simple. It isn't sucking enough air through the radiator at an idle. Lots of people will tell you that you can test the fan clutch by trying to turn it by hand when the engine is not running, but my years of troubleshooting have taught me not to trust that diagnostic method. Personally, I would hit the salvage yard, or pop for a new fan clutch. They are $35 at Autozone.

Many XJ's don't even come with the elecric fan and it shouldn't even be needed to keep it cool at an idle.

I had the very same problem with my Mazda Prodege'. Different vehicle but it still is the identical problem. It would accually boil over at stop lights and drive throughs. I checked my fans and the ops checked good. It came down to bieng the thermo switch that controlls the elec fan. When you come to a stop have the A/C on. This forces the fan to stay on. THat is a temp fix. Check the Hayes manual or if you lucky enough the FSM. I'm not sure about the 89 but do all of the ops checks in the Hayns manuals and I can almost bet its the themo fan switch.

Good luck

On the 89 its called coolant temperature switch

thankyou old man. it sounds like u really think its my fan clutch. i understand what your saying and im probably going to go ahead ahd just get the new fan clutch first since its on 35 dollars. if this doesnt work then ill head toward the radiator... by the way is installation hard on that ???

3 Row CSF Radiator at autozone. Like $140 and warrantied out of the store. They are on-line too. Check E-bay. Mine works wonderful. The clutch fan is another huge issue especially where it over heats when sitting still. The way to check it is when the motor is hot , turn off the engine then try and turn the fan. If it turns it is shot. The fluid when heated up makes the clutch engage and it shouldn't turn which mean when the engine is running it does turn with the pulley. When it doesn't engage it just kinda spins loosely and doesn't create the forced air. If that doesn't make sense PM me and I'll research and find a more professional explaination.
Good Luck !

The install isn't all that hard, but is notorious for claiming a little skin off of the knuckles. It is a tight squeeze getting in there to get the bolts out. If I remember right, it helps to pull the plastic radiator shroud.

thankyou for your help everyone i think im giong to just buy a new fan clutch and replace it. hopefully its easy to replace

Actually the easiest way I've learned is removing the radiator first. I bent the crap out of my fins on the radiator, which I ended up replacing after wrecking it right after the clutch fan swap. It can be done with out , but like old_man says it is knuckle skinning job. You might just take the top support piece off the radiator and the brackets so you can push it back a little out of your way. Don't pull it all the way out or then you have a hellava time getting the rubber grommets back in place the radiator rides on for support and shock absorbing.
If it is still Overheating after that I would really look into a new radiator. Not really worth having yours boiled or cleaned it probably wouldn't last long and no warranty.
Good Luck !

I definitely agree with old man's diagnosis. Only other thing that I think it could possibly be is the water pump. It might not be pumping enough coolant at low rpm, but you say the pump isn't leaking so probably unlikely.
Is your belt tight? If it's slipping that would explain the lack of coolant flow.

K

generalleexj said:

thankyou old man. it sounds like u really think its my fan clutch. i understand what your saying and im probably going to go ahead ahd just get the new fan clutch first since its on 35 dollars. if this doesnt work then ill head toward the radiator... by the way is installation hard on that ???

Click to expand...

might as well do both while you're there
a new radiator is one of the best gifts you can give your engine and your Jeep