Any Jeep Cherokee 4.0 Gurus out there?

[Mucho_MPG]

Picked up a 92 Jeep Cherokee with the 4.0 inline 6 cylinder. It has 200K on it, and I got it for practically free.

Previous owner says he replaced the head gasket and water pump but hasn't driven it much since he did that. The truck has sat for the past 12 months.

Well, the truck runs smooth and pulls strong, but like clockwork the temp gauge moves to the red and I have to shut her down. This happens approximately every 15 minutes. I notice every time I park it and come back after a half hour or so, I have about 4 or 5 ounces of coolant dripping from the upper transmission housing.

Any ideas on this? The four wheel drive in it works great so it would be nice to occasionally use it to go to work in when it snows heavily. I am only willing to put 300 or so dollars into this truck to solve this overheat problem.

I plan on flushing out the coolant, replacing thermostat, etc., and might try to live with the slight coolant loss. If not, then off to the junk yard for her but I really don't want to do that.

Thanks guys!

 

[Eddie]

There are two water pumps availiable for the 4.0. One turns CW & the other CCW. I wonder!!!!!

 

[Gary Allan]

Quote:
I notice every time I park it and come back after a half hour or so, I have about 4 or 5 ounces of coolant dripping from the upper transmission housing.


Well, that coolant isn't coming from there. The back of the head maybe. I dunno if there's a sand core plug there or not (never got around back there. It's tight) ..but even that should start leaking immediately upon start up ..and that still wouldn't explain the 15 minute wait for the over heat event. The head gasket issue tends to make me think it's a deeper issue. That is, something wasn't done right with the refit and they gambled and lost with the work performed.

I sure that you've opened the hood when the overheat occurs and found nothing spewing out of anywhere ..so this kinda confounds simple narrowing down. The coolant leaking should be able to be duplicated with a pressure tester.

 

[Mucho_MPG]

I think you are spot on Gary. I think that there is a deeper problem at work here. I think the guy (who is in his early 20's and says he is a mechanic) probably didn't do the head gasket correctly and/or he overheated it a few times, slapped an HG on there and I am now dealing with a warped head. Too bad as the vehicle looks nice and I have always wanted a Jeep.

I'll post the findings of my investigation of this problem.

Thanks guys!

 

[Mucho_MPG]

Gary, my dad took the rad cap off and blew into it. His exhalation caused an immediate drop in fluid level, so I have got to track down that leak down first thing Monday.

Interestingly enough the new car sticker still in the glove box reads that the vehicle sold for 22,672 back in 1992. I figured back then this vehicle would have been under 20K.

 

[Chris142]

Yes there is a freeze plug in the rear of the block. Gotta pull the trans to get to it.

The 4.0 has a special coolant fill procedure to help get the air out of the system.

Remove the heater hose thats connected to the thermostat housing at the housing. Put a funnel in the hose and pour your coolant into the hose, through the heater core untill coolant begins to come out of the nipple on the housing where the hose goes.

Put the hose back on and fill the radiator or degas bottle. Run it 20 min or so, watch the guage, shut it off. Walk away. Check the level and fill as necessary.

If your just pouring water into it w/o doing the heater hose trick you will have a hard time getting all the air out.

 

[Gary Allan]

Quote:
Yes there is a freeze plug in the rear of the block. Gotta pull the trans to get to it.


Glad you know, Chris. I've never seen the naked back end of one of these.


Even if this required ONE or the OTHER (either a reman head or pulling the trans to do the freeze plug- if that's what it is) it would be worth it to me for the rest of the vehicle in good shape. Neither of those procedures are that expensive or complicated to perform. Both would probably render the thing parted out junk.

 

[meep]

Before panicking, note that fluid can roll down the slope of the engine towards the rear.

Check T-stat housing for leaks. Inspect water pump. May need a new T-stat (195*) anyway. The housings corrode from the inside, consider just replacing the housing for $15. Check heater hoses at engine-side for leaks at clamps. Also check cyl head torques, maybe they aren't correct (115 ft-lbs).

Bottle of stop leak (prestone) helped me.

M

 

[HawkeyeScott]

"Interestingly enough the new car sticker still in the glove box reads that the vehicle sold for 22,672 back in 1992. I figured back then this vehicle would have been under 20K."


That sure does seem pricey. I have a 1987 Grand Wagoneer that I bought with the original window sticker in the glove box. That vehicle's MSRP in 1986 was nearly $25K at a dealership in Omaha, NE. I was amazed.

 

[Mucho_MPG]

Thanks for all the great suggestions guys. I will try to take a look at the water pump housing, thermostat housing, heater hoses, etc. If all else fails a guy will buy it from me for 600 bucks. Head gasket work scares me as I do not have the technical know how, tools, etc. to perform this kind of surgery. Hopefully, it is something easy and requiring little mechanical aptitude to accomplish. LOL!

 

[mstrjon32]

I got the window sticker with my used 1999 Cherokee Sport - $25K. There are plenty of options it's missing, too. I'd imagine a fully loaded model would have set you back nearly $30K.

 

[NYEngineer]

I don't know... The fact that you like this thing and it generally runs good, You may want to try and fix it.

I hate to see otherwise good cars parted out.

 

[D189379]

Originally Posted By: Mucho_MPG
Thanks for all the great suggestions guys. I will try to take a look at the water pump housing, thermostat housing, heater hoses, etc. If all else fails a guy will buy it from me for 600 bucks. Head gasket work scares me as I do not have the technical know how, tools, etc. to perform this kind of surgery. Hopefully, it is something easy and requiring little mechanical aptitude to accomplish. LOL!



I replaced the entire cylinder head on a 4.0 without any training or help. It's within most peoples ability.

 

[Mucho_MPG]

Me and Dad did the following today on the old Jeep:

1. Replaced thermostat with a new 195 degree one

2. Flushed radiator again with the 10 minute flush stuff

3. Bled out entire system both from the heater hose and from the coolant temp sensor located on the thermostat housing

4. Refilled with 12 quarts of 50/50

Well, I drove it around for about 20 minutes and this time it did not overheat. However, the temp is still on the high side (just past the 3/4 mark which is about 225 degrees. It stayed there pretty good, so I'll take that over 260 degrees like happened yesterday.

So it is getting better. The only last thing we can come up with is that is needs a new radiator. Other than that, I am at a loss. I have a guy coming over Sunday to buy it for 600 bucks if I can't solve the overheat problem, so at least it will go to a good home instead of the wrecker.

 

[Mucho_MPG]

Originally Posted By: D189379
Originally Posted By: Mucho_MPG
Thanks for all the great suggestions guys. I will try to take a look at the water pump housing, thermostat housing, heater hoses, etc. If all else fails a guy will buy it from me for 600 bucks. Head gasket work scares me as I do not have the technical know how, tools, etc. to perform this kind of surgery. Hopefully, it is something easy and requiring little mechanical aptitude to accomplish. LOL!



I replaced the entire cylinder head on a 4.0 without any training or help. It's within most peoples ability.


It is not within mine. Very little in the way of tools, and I am far from being mechanically inclined. My Dad could do it, but he is 68 years old and I will not impose by having him attempt something like this. He has already helped me out immensely on this Jeep already.

 

[Gary Allan]

Make it a quality time project for old time's sake. You provide the muscle. He provides the knowledge.

 

[Mucho_MPG]

You know, that just might just work.

After 45 years of working on planes, he might be able to teach me something on cars as some of the stuff crosses over a bit.

 

[Zaedock]

XJ's typically run on the warm side. 225 isn't uncommon. My YJ Wrangler trail rig now sits on 38's, so I'll be building the Cherokee for mild trail use (Massachusetts + 38" tires = Fail).
My XJ usually runs about 200-205 on 80-85* days. I was planning to install hood louvers to expell some of the hot air trapped under the hood. As you've noticed, there really isn't a lot of room under there for good flow. There are a couple of companies out there that make decent rivet/screw on hood louvers.