So I went to Napa today to purchase a heater core and hoses. The hoses he gave me couldn't have been any longer than 8 inches and both had bends in them. I told him to hold off on those because I could have sworn that the two hoses I needed, need to be able to reach from the firewall to the front of the engine bay. When I said something about them not being the right ones, he also said something about a valve that goes in between; which I was not aware of. Also, on my way out the door, I opened the heater core box to check it out... it looked like it was aluminum; I asked for/purchased the copper/brass one.

Does anyone have a diagram of the cooling system? Is there in deed some sort of valve that goes in line w/ the heater core? Do both hoses go directly from the heater core to the thermostat housing? HELP!

 

Sounds like PO may have eliminated the heater control valve.....lots of folks do. The factory eliminated the valve on '97 up XJs. The heater hose between the water pump and heater core is 5/8", the hose between the heater core and t-stat cover is 3/4".

 

There is a heater control valve between the heater core and the water pump/tstat.

It is fairly close to the firewall, 8 inch hoses sounds about right, 1 inlet and one outlet from the heater control valve to the heater core. The longer hoses connect on the other side of the valve to the tstat etc.

Not trying to be rude but could you not just poke your head under your hood and see that? Maybe you are at work, who knows. The heater core replacement is pretty involved, about a 8-12 hour job.

 

thats another possibility =D

 

WOH! First, your problem was? I can tell you from decades of actual hands on experience that a tube of Alumiseal might solve fogging from a pinhole in the heater core. Not the similar Bar's leak! Looks the same but might gum things up. The little tube, diameter of a quarter, NOT Bars Leak brand. That fine powder will not mess tings up, but WILL find it's way to plug pinhole sized leaks that can cause fogging and smell.

The guys are right, most of that phet IS phet. But guess what. Fine particles of aluminum will not hurt anything, and have for me stopped fogging and that smell. It does take time. Give a small 3 inch tube of it a week to see.

No doubt, don't use the gummy stuff unless you are selling it to Romney, but a little aluminum dust aint gonna f things up, and has saved me two or three magor headaches.

 

FWIW... I have had my head under the hood a handful of times; and from what I see, the heater core has been bypassed... one hose going directly from the inlet to the outlet of the heater core. the other hose goes from the inlet to the outlet of the thermostat housing. I do not see any sort of bypass valve near the firewall anywhere. Is it safe to say that I can just hook the heater core back up w/o the bypass valve... seeing as how they did away w/ it after '99?

 

What happened?

 

What?!? Yeah, you can run the hoses straight the heater core, lot's of people eliminate the control valve.

 

No kidding, what are you trying to say dude? Lol

 

Ahhh......it stopped leaking?

 

That wasn't so bad. My first attempt ever w/ a heater core and I would do it again if I had to. I managed to get the job done today, in 7 hours; that includes about an hour for lunch and two trips to the parts store. I am one happy Jeeper now... just in time for the Florida winter.

 

No s**t? What are you doen' Tuesday? Well done! Florida winter...second week of January isn't it?


Oh and YES, the alumaseal fixed mine.

 

??????????? Who are you talking to?
That must be some good stuff! Can I have some lol?

 

End result, I may have been able to just flush the alreadybypassedheatercore and made it work, but there is a nice 2 inch hole in the front left passenger footwell which led me to believe the core was leaking. On that note, I now have a heater core that will more than likely outlast the Jeep

 

there are shortcuts, you can pull the whole dash out in a few bigger peices, had it done in 3.5 hours.