Can I use a later XJ Heater Core

[howeitsdone]

Searched & Searched but couldn't find a topic.

 

A heater core is less expensive if I buy a '94+ type. Is there really a difference? The pictures look identical.

 

I am converting to open cooling and wondering if putting in a later model core would work. My current core is non-functioning so I have to replace anyway. If it matters, I don't have A/C. Also, does that matter? Wouldn't think so...

[Dickinson County Comanche]

I think it should work. Later heater cores will have a different size fitting than the one that you have has. I think all the heater cores from 84-96 were the same minus the fitting sizes

[Dickinson County Comanche]

Also have you tried flushing the core? My heat didn’t use to work but I flushed a ton of junk out and now it works great.

[cruiser54]

gross!! 

[howeitsdone]

That's pretty! lol

 

I haven't removed the dash yet, but this seems pretty telling already. Do the fittings go all the way through the firewall or connect to the hard lines in the firewall itself? I'm not concerned if the hose in the bay needs an adapter.

 

[howeitsdone]

Bump.

 

Trying to understand if the different fitting size will be an issue. Based on this diagram, it looks like a seal could cause issues so maybe I can just replace. Otherwise, wouldn't this eliminate the need for a hose adapter when converting?

 

[howeitsdone]

For reference, both of these parts confirm fit in a Comanche:

 

OSC 98024

OSC 98732

[AZJeff]

The heater core input/output pipes extend through the firewall just far enough so that heater hose can be slipped over them and clamped on.

 

The foam rubber seal you see in the diagram is intended to keep water and air from the engine compartment from getting into the cab of the vehicle.  It plays no part in the actual sealing of the coolant lines to the heater core.

 

Since you are planning on replacing your core, there is a good chance that foam seal will be trashed with dry rot when you try to remove the core from the seal.  If that happens, just get some other foam at a hardware store or fabric/sewing shop, and cut something to fit the space.  Use contact cement to hold it to the heater box.