waterpump diagnosis/overheating problem cont'd...

[dingus]

1042947

ok... my jeep is still overheating, now after replacing the thermostat. i'm gonna pull out the radiator thursday to check that out, but i'm wondering about the waterpump too... when the car is idling, it overheats. when its moving, it doesn't. when the AC selector is anywhere but "off" (the one with like, AC HIGH, normal, bi-lev, heat, defrost) it tends to make a squealing noise from the front. i don't think its the serpentine belt kuz it was just replaced. the hot-cold selector has no effect on this.



i tried running some "radiator stop-leak" which i've heard mixed opinions about, and i'm gonna take the radiator out and flush all the crap out of it, hopefully it just needs a good cleaning. also, when i look down the overflow tank, i can see the particles of this stop leak crap just floating around... i don't like that at all.



i'm now running a 180 degree thermostat, if that helps. do you think my waterpump bearing is going bad? [addsig]

 

[bob]

1042948

sounds like your belt is not tight enough. also after your engine gets really hot turn it off and see if the fan blade moves if it does you have a bad fan clutch.

[addsig]

 

[dingus]

1042957

well last night it died on the way to the shop. i dropped it off around 9:15 pm, and it stalled out and coasted down the street for a while, and i realized that when i stepped on the gas that it was off. so i shifted it out of drive into neutral and turned the key, and mashed the gas. it had basically no power whatsoever, but it chugged into the parking lot where i switched it off and dropped the key in the slot. i'm sick of dealing with it now. hopefully i didn't fry the piston rings (which might explain the lack of power, no compression

) arg... and maybe the head gasket went too.



so, i'm pondering replacing the motor. its a '90 cherokee 4.0 litre, but its a non-high output. will any I6 motor swap in here? i'm not interested in changing the wiring harness and all that nonsense, but it'd be nice to put in a nice motor from a newer cherokee. i'm currently at 144,xxx miles. how much do these motors cost, anyway? are there any other motors i should consider?[addsig]

 

[dingus]

1042979

ok... (well, besides the fact that i'm talking to myself here) i have an update...



the jeep needed a new radiator. damn that stop-leak crap! oh well... 330 bucks later, the jeep is running 'normal' again... its fine! i paid the shop to do it because i don't have a free moment until next week to put one in, and i need it every day until then. so much for that. the damage was something like 150 for the new radiator, and about the same for labor/diagnosis.



i didn't get a chance to wash the jeep before bringing it in, and the guy at the desk asked me 'where have you been offroading?'... and i'm like "i can't tell you"... haha.. it was COVERED in mud...



-nate[addsig]

 

[balloo93]

1043033

What year XJ do you have? Just curious if they installed a open or closed style radiator.[addsig]

 

[dingus]

1043061

'90 XJ ltd... i wanna say its closed (meaning there's no fill cap on the radiator itself, there's the overflow tank)[addsig]

 

[balloo93]

1043244

Man, not to be a downer, but you should have considered a open cooling system convertion. Real easy to do, the hardest part is on the pocketbook.



Have you considered a stroker motor? There are quite a few article out there about the 4.6 and 4.7 stokers. They seem like they would be pretty reliable. About all you'd need is a 4.0HO head and a better exhaust header or a HO header and it would scream. I think when I was just looking around, I had found a couple of rebuild kits for at or around $300-350. That doesn't include taking it to a shop and having it vated and honed.



If I had to guess you'd probubly be able to just get a good rebuild on your stock 4.0litre for around $600 (maybe cheaper) if you did the assyembly yourself.[addsig]

 

[dingus]

1043252

yeah, i'm not adverse to more power... but i'm happy with it now... i'm more concerned with getting my new lift on

if i were to do anything serious to the motor i'd get a newer high-output 4.0 motor...



rustys' 3" spring pack lift is on the way...[addsig]

 

[balloo93]

1043270

Full packs, or AAL's?[addsig]

 

[dingus]

1043283

full packs... my rear springs are sooooo sagged right now it wouldn't work with aal's...

[addsig]

 

[SoggyBottom]

1048053

dingus,

I've got a '95 XJ with the exact same symptoms as yours. Jeep didn't mess around with a good design for 10 years, but it looks like they didn't fix any problems, either.



Anyway, I'm gonna try replacing the thermostat in the hope that a $20 fix will avoid a $330 radiator. Did you ever figure out where the coolant was leaking from that time you pulled over and it came flooding out all over your driveway? That happened to me yesterday. I still can't figure out why the temp goes back to normal when I'm driving, but skyrockets whenever I idle or slow down.



Anyway, just wanted to let you know your troubles are appreciated by this jeeper.



-George[addsig]

 

[bob]

1048066

check your fan clutch! also your raditor might be clogged. [addsig]

 

[MudderChuck]

1048071

Generally gets more air when you are moving and cools better, also the water pump, pumps more coolant as long as the motor is hot enough to open the thermostat.

Don´t know about the 95´s per say but alot of the XJ´s have a low profile (sharp bend) thermostat housing and a low profile thermostat that seems prone to messing up. On many models and with after market thermostats you have to be carfull how you put that thing in there as sometimes it can deform when installing.

Sometimes when the system has a little leak, or the coolant resevoir goes empty, the system picks up a little air that migrates to somewhere where it shouldn´t be and slows down the coolant circulation. Parking it with the nose up on a steep hill and reving it a couple of times seems like the easiest remedy.

The secondary, electric cooling fan, should come on sometimes if the motor is overheating. If it doesn´t, it is usually a faulty thermoswitch, left side of the radiator, which can be jumped to provide continueous electric fan, on many models. Or possibly a fan relay.

Between the radiator layers on the outside but hard to see, though the radiator looks clean from the outside, there can be mud, crud and organic material (sometimes snow)that is slowing down air flow. Can be checked with a strong flashlight shinning from the motor bay side of the radiator, towards the grill and following the light closely with your eyes in kind of a grid inspection. Cleaning it out can be difficult without bending the fins on the radiator with high pressure water.

Don´t know about how cold your part of the country is, but partial freezing of the coolant (wrong mix) will sure cause a motor to overheat. Worth checking especially if it is an intermittant problem.[addsig]