Long story short that black 4-way plastic thing which sens the coolant into my heater core got a small crack in it and was leaking. Being as it is late March and was 70 degrees all last weekend I just took the thing out and looped the hoses so the coolant wasnt even heading towards the heater core anymore. But surprise surprise the temps taken a late plunge and it`s been near 30 in the mornings. Since I`m without that plastic thing I have just hooked the lines back together so the coolants just flowing freely into the heater core and back out. Aside from the fact I won`t be able to adjust the temp (Aside from turning the blower lower) will any harm come from this for the next week or so until I replace the plastic thing? (Whatever it`s actually called)

 

Except for your not being able to regulate the out-put temp of the heater/ac unit, running without the heater control valve won't hurt anything. IMO
Dan

 

Watch out when you go to replace that thing, Jeep must have made ten different versions of that part, lol. The hose barbs point different directions on some, the little vacuum valve points different ways or is made of different materials. Just bring the old one to the JY so you can match them up proper. Oh and you should be ok running it like it is temporarily.

 

I have strait line from pump to heater core and t stat houseing to heater core with no problem. I will just put a ball valve on it this summer to shut it off so no hot water comes in the cab.

 

Actually, in the later models of the XJ, they no longer exist. SO, no there is nothing wrong with getting rid of it. It is just something bad waiting to happen. There are a few threads over at the naxja forums about it, and not sure if there is a "write-up" or not.