Possibly Running Hot ?

[restrorob]

Hi all,

I bought a 93 XJ 4.0 with 156000 on the clock.

I drove it lengthly today for the first time and noticed the temp gauge shows a 220 running temp. Is this not a little high ? What would be a normal running temp on these Jeeps ?
I did search for about half hour and found no answer, But I did see they do like to run on the hotter side. Boy they skimped on these radiators !

[Ray H]

220 is a little high. 210 is generally a reasonable temp for these engines to run. The cooling system in a Cherokee is adequate when new and everything is in good shape. As they age, it gradually becomes less than adequate. There are a few things that could be effecting your cooling and they will have different symtoms. If its running hot while sitting still or moving slowly, its most likely the mechanical fan thermal clutch. If it runs hot while cruising, its probably a radiator issue.
I think the biggest problem with the XJ cooling system is the small sealed engine compartment. Theres just not enough fresh air moving through the radiator because it has no where to go.
Ive installed a 3 core radiator, hi flow water pump and t-stat housing and mine still gets up to 220 if its hot out and sits long enough. At about 220 the electric fan kicks on and cools it back down but If I pop the hood open, it never goes above 200.

Of course another problem you could have is the gauge or sensor. They a notoriously inaccurate.

[restrorob]

Thanks for the info., Driving down the road it stays on 220 but I stopped and let it idle for about 5 mins. and when I got back in it was a little above 220.

I have no problem replacing everything in the cooling system to prevent a overheated blown engine. I've found a new 3 core radiator at a good price but what's your thoughts on a adjustable thermo activated electric fan to do away with the clutch fan ? Less drag on the engine ? Maybe adjust it to kick in at 195/200 ?

[AlohaBra]

Ray's post is good...

Start with a radiator if the fins are rotted out and a new thermostat.

I just changed my t-stat..it was 10 years old and the gasket was leaking...it was running at 210...now it is at 209 F....

On the temp sensor...pull it out and clean the thread and the sensor part and see if it changes anything...

Aloha..

[Ray H]

Originally Posted by restrorob

I have no problem replacing everything in the cooling system to prevent a overheated blown engine. I've found a new 3 core radiator at a good price but what's your thoughts on a adjustable thermo activated electric fan to do away with the clutch fan ? Less drag on the engine ? Maybe adjust it to kick in at 195/200 ?

My thoughts on an electric fan, Hmmm...
I always take heat for this (pun intended). I dont like them, but I dont like power windows either, so Im just old fashion that way.
I actually installed a flexilite 110 (if memory serves) a few years ago when I put my 3 core in. My experience was that it didnt pull as much air as a stock mechanical fan with working clutch. I saw no increase in cooling. I pulled the electric fan out after about a year and installed my mechanical fan back in. I will say that the engine seemed to rev faster with the electric fan but I really didnt see a change in mileage or any actual power gains. Lots of people like the electric fans, they are a common modification. Im in the minority so Im not going to tell you they are good or bad, just relaying my experiences. I think the best mod to start out with is a nice 3 core or even a big 2 core radiator. (may as well install a tranny cooler while you do the radiator). After that, a good bang for the buck mod would be hood vents to get rid of the hot air. Vents are becoming popular now that XJs are getting up in age and not as many people are afraid to cut the hood up.

[restrorob]

Thanks Ray and Aloha,

So the plan is 3 core radiator, T-stat & clean temp sensor and fan clutch.

Question on the trans. cooler;
I noticed in the cooler line a big crimped on high pressure hose, Doe's it actually need this big hose ? I have a little seep at the crimp. Can I cut the steel line behind this big hose to add the aftermarket cooler ? Must I use high pressure hose to install the cooler ?

On my truck below I just flared the end of the lines to keep the "standard size" P.S. return hose I used from sliding off.

[Ray H]

Originally Posted by restrorob

Thanks Ray and Aloha,

So the plan is 3 core radiator, T-stat & clean temp sensor and fan clutch.

Question on the trans. cooler;
I noticed in the cooler line a big crimped on high pressure hose, Doe's it actually need this big hose ? I have a little seep at the crimp. Can I cut the steel line behind this big hose to add the aftermarket cooler ? Must I use high pressure hose to install the cooler ?

On my truck below I just flared the end of the lines to keep the "standard size" P.S. return hose I used from sliding off.

Most aftermarket coolers will come with section of hose so that you can cut and splice where you need. I wouldnt see a problem cutting the hard line, just make sure the rubber line isnt in contact with anything it shouldnt be. Are you sure its leaking at the crimp? The usual leak point is the quick disconnect fitting.

[restrorob]

Originally Posted by Ray H

Are you sure its leaking at the crimp? The usual leak point is the quick disconnect fitting.

Well as they say, "A pic is worth a thousand words"





So there's no problem with cutting both lines before the large hoses and routing the new ones through the core support to the cooler right ?

[Ray H]

Nice pic.
I dont see a problem cutting that section out and running a longer rubber hose.

[restrorob]

Thanks for ALL the info. Ray and Aloha.

Got the plan, Now time to get to work !

[AlohaBra]

Hey Rest...what we usually do in the shop is to grind the swedge off of that hose in your picture and replace the hose.

Then we put worm style clamps on it. If you are paranoid about the hose slipping off, I would put some glue on the pipe (like weather strip adhesive or silcone sealant). Make sure you let the glue dry.


BTW a transmission cooler is cheap insurance.