After lunch, I walked out to the Jeep and saw a sizable puddle of something under the front end, about where the mech fan is. A quick check revealed it was a darkish, oily liquid. I also noticed it had some neon green mixed in. After popping open the hood, I see it's wet around the bottom of the radiator. An obvious wet spot/dark discoloration was about 2 inches up from the radiator bottom and appeared to have a drip trail. The tranny fluid is at ADD on the stick and there's almost no radioator fluid in the tank.

I am therefore deducing that the radiator sprung a leak in both the built-in tranny cooler and the radiator. Is there anything you can think of that might be the case? Busted hoses, perhaps?

 

Sounds like you lost the radiator. Sorry man. Its a fairly easy replacement job to do.

 

The radiators seem to go often on XJs. I have a '98 that I am changing the freeze plugs out on tomorrow and also have a radiator leak as well, so I am putting a new rad in also. Doesn't seem like too hard of a job compared to the freeze plugs which is just very tedious. I'm fairly new to mechanical work and have managed to remove the power steering pump, intake and exhaust manifolds that consumed my whole evening. Here's a pic of my freeze plugs and you can clearly see which one's leaking--you may want to check yours out as well.

 

It's possible it could be the water pump but it's prob. the rad.

 

If you do the radiator, do the water pump at the same time (unless it's been done recently).

And also consider a new 195 degree MOPAR thermostat, hoses, radiator cap. Every penny you spend on cooling system maintenance is money well spent.

 

Well said....... Food for thought the copper brass rad can be repaired readily as a plastic aluminum cannot.

 

I checked the water pump first thing, but I'm fairly sure it's just the rad. It doesn't really matter, I guess I'll put in a new water pump anyway.


Yeah, I suppose I might as well do all that. I just ordered a CSF 2 row all-metal from Radiatorbarn.com. I figured I might as well install an aux tranny cooler while I had the grill opened up. Then, I figured I might as well do the Putco headlight wiring upgrade and run the wires for some Hella 500s I want to mount onto the brush guard. Might as well, right?

 

While you have the water pump off might as well change the timing chain.

 

wouldn't worry about the timing chain but change the fan clutch its already off...

 

I've pretty much decided to change the power steering pump, too. It's been leaking and sometimes it works, sometimes it doesn't.

Wow, can there BE anything else to change?

 

Of more importance perhaps, the reason for such failure in the first place. When I took over the maintenance of our XJ, it was obvious that regular maintainance had been ignored, including regular coolant changes, with the proper coolant and distilled water mixture. The sludge flushed prior to parts replacement was vile. The coolant had become so acidic that it destroyed nearly everything in the cooling system.

Age alone does not destoy parts from within. Food for thought...

 

I thought about that, but finally attributed it to taking it off-roading in the recent freezing conditions and the age of the vehicle. As far as maintenance, I can only account for the time I've had it (early 2010) and I did a complete fluid change back then.

 

I had a small leak that I couldn't find. I finally went for it and changed the radiator, water pump, thermostat, tstat housing, and all the hoses. Worth every penny, my temp was always above 210 and now it sits below 200. This summer I was out in the mountains on FS roads and it never got above 200, it used to always get hot when I was up in the mountains.

 

My XJ has an odd issue, my temp fluctuates from about 180*-210* quite rapidly, it will suddenly drop then climb back up. It's been topping out in the 40's here lately so i'm not sure if it is a problem or if it is normal. I would think the gauge would stay about the same at a certain temp. This makes me think it could be 1 of two things. 1: the temp sensor at the back of the block could be bad (it has quite a bit of oil on it from a leaky valve cover gasket) or 2: the thermostat is bad and is sticking. Ideas? I recently found out the radiator in it is 1 year old so that is good. Does this sound like a reasonable diagnosis? Sorry to hijack the thread.

 

Same here in the prior ownership. We bought from a big-city type who never bothered to service the cooling system. Even though I changed the coolant and flushed the overflow bottle which was NASTY, the radiator died 6 months later due to chronic neglect.

Thankfully, the casting plugs are still in good shape, likely because well-meaning prior owners didn't put the "classic green stuff" inside. We ended up replacing the radiator with a new, copper 3-row unit from RadiatorBarn.com, OEM pump and thermostat, and Gates hoses all around.

Pat yourself on the back for the maintenance. Very few bother these days. I've glanced at engines at filling stations when owners pop the hood, and have been shocked at how badly they're neglected.