XJ Coolant system leak

Late last winter I had a freeze plug blow and the Jeep overheated a bit. Since it was very hard to get to I just replaced it with a rubber freeze plug. I dont know if that has anything to do with it, but it seems it might.

I now loose coolant and can smell it in the cab when the heat is on but the core still puts out good heat.

I'm not familiar with the heating system and am wondering if there is anything besides the core that could leak. Anyone have any suggestions or guesses?

Reply to
Matt Mika
Loading thread data ...

Reply to
FrankW

Would'nt I have a head gasket leak or something if the head warped? There's no water in my oil, no funny exhaust or anything out of the ordinary except I loose coolant and can smell it in the cab once its heated up.

I figure the problems with the heat>Hopefully you didn't warp the head after it overheated

Reply to
Matt Mika

Ouch!

I would first look really closely where the heater hoses go into the firewall on the passenger side for a loose clamp or pinhole in the hose.

Otherwise, smelling it inside means the heater core has gone bad. This isn't a fun job to change...... The console and whole lower dash have to come off to get at it. It is a 'full' days work usually.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Matt Mika wrote:

Reply to
Mike Romain

Yes, I've heard its a real PITA! But I guess its better than a warped head!

If the core still heats well and I can find the leak is it possible to just seal it with epoxy or something? Or should it definitley be replaced altogether?

Thanks

Reply to
Matt Mika

Reply to
FrankW

Nope, it only smells when the heat is on...

Yea, I was certa>It can't be your head (I needed to read your post more carefully)

Reply to
Matt Mika

Well, I would use some good radiator stop leak if the hoses are indeed tight and whole. All the hoses are on the engine side of the firewall.

The radiator stop leak might just do the job though. If not, then you may as well change it vs patching after going through all the trouble to get to it...

Mike

Matt Mika wrote:

Reply to
Mike Romain

Decades ago my then-(now ex-)wife had a Mitsubishi Sapporo that was leaking coolant from someplace high at the back of the engine. I figured it was a freeze plug in the head. When I got the head off (in the dark, without cover, in the snow) it turned out to be the head gasket. A tiny section by a water passage had failed towards the outside. No water in the oil, no water into the cylinder, no bubbles in the radiator tank, just a leak down the back of the engine.

Without running out to look at my 96 XJ to see, is there a way you can isolate the heater core from the coolant flow, pull the hoses and bridge the gap with hose somehow? That way you could run the Cherokee up to temp and see if you still get the coolant smell. It would suck big time for you to pull the dash apart only to find that the problem _isn't_ the core but is really the water pump dribbling just enough coolant into the wind to make it smell.

Reply to
Lee Ayrton

Another thought: Some (all?) model years of XJ have a coolant tank mounted up on the firewall, passenger side. They crack and leak. I would never have found the leak in my `89 if I hadn't passed my hand through the nearly invisable stream coming from a tiny crack. The loss was so slight in mine that it never left a drop under the truck. If you are lucky this could be the problem with yours, and the vapor is streaming up and into the fresh air intake for the cabin.

Reply to
Lee Ayrton

Thats a good suggestion. I can easily bypass the heater core for that experiment.

Thanks

Reply to
Matt Mika

Reply to
mic canic

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.