twm3000

I was wondering what this part was called. My hoses hook up to it. It has two little pin holes in it and is spraying radiator fluid everywhere. Looks really easy to change out though.

timamybrown

Heater control valve.

twm3000

Could I get that at Auto Zone?

cruiser54

Yeah, but don't Just eliminate it.

Thanks to djb383 for this:

One thing you may want to consider, is removing/eliminating the heater control valve, if you haven't already. '96 down have the HCV, '97 up the Factory eliminated it.

During the warm months, with a HCV, (temp lever/**** never moved off cold) coolant sits and stagnates inside the heater core.....There's no fresh coolant/corrosion protection circulation through the heater core.

With the HCV removed/eliminated, coolant/corrosion protection flows through the heater core constantly when the motor is running, regardless of where the temp lever/**** is set.

Also, you don't have to remember to turn/slide the heat lever/**** when flushing/re-filling the cooling system because coolant is flowing to/through the heater core when the motor is running and the HCV is absent.

Be sure to plug/cap the small vacuum hose when eliminating the HCV.




HCV Removal



The heat is controlled by the blend air door. I've eliminated at least 10 of them here in Arizona and my AC always works perfectly.

Let's not have this thread turn into one of those where folks think theory and conjecture trumps actual field experience which has been proven time and time again, by numerous different people.

It flat works. Period.

I've already stated the other benefits of keeping coolant flowing versus being stagnant in the heater core and the dangers/disastrous results of having one fail unexpectedly whether you're poking around the engine bay or driving down the highway or trail.

extrashaky

I was slow, and Cruiser beat me to it. But here it is anyway:

You could, but it will break again. The good news is that you don't actually need it. In fact, they were deleted permanently from the later XJs because the almost nonexistent benefit they provide isn't worth the hassle. You can just take it out and replace it with hoses.

Search the board for HCV delete. There are a bunch of threads on the subject, and pretty much everyone who gets rid of it is glad he or she did.

If you're feeling irrational and decide you MUST replace it, apparently some of the 4-cylinder XJs came with metal HCVs that hold up longer. But just delete it. That's a lot easier.

twm3000

Cool. Thanks for all the input.

94XJAZ

I like the idea of removing an unnecessary moving/mechanical part, one less thing to fail. I bought my 94 about six, eight months ago for a desert toy and to drive around town, a DD when I want. It needed help, everything that can leak, was leaking! Yes I believe everything haha. Still have an oil leak, I believe it is either the distributor, oil sender or filter adapter. Back to the HCV. Does anyone that is intimately familiar with the Heat and AC system know or has looked at modifying the system to allow the heater core to vent outside when its 110 degrees here in AZ to help with cooling? I am NOT saying this IS possible, just wondering if we could figure out a mod to add an optional air door to the outside. I have learned the XJ needs all the tricks possible to keep it cool, turning on the heater adds cooling, it would be great to not get cooked alive while doing so.
Impossible-maybe
bad idea-maybe

cruiser54

Probably not worth it.

A well maintained cooling system should work fine. Do you do slow trail stuff? If so, think about upgrading to the ZJ fan clutch.

94XJAZ

I agree, probably not worth it but had to ask.
So in your opinion is the ZJ fan clutch a better route than going all electric?
I have replaced/upgraded my entire cooling system with a three row metal radiator, all new hoses, new Hesco Hi perf pump, Hi flow T-stat housing and a high flow 195 deg. thermostat. Flushed block and heater core. Still gets a little warmer than I would like when it's hot out(210). kick on AC and temp goes down to 195 ish. I have not yet vented the hood or changed to a HD fan clutch.
Yes on the trail stuff, I like AZ pin striping! Ha Ha

cruiser54

The ZJ fan clutch is cheap. And kinda loud. Napa # 272310.

Your cooling system sounds impressive!!

94XJAZ

I will probably try the ZJ clutch first.
As far as the cooling system goes, It makes me cringe when I see the temp up, I know it is killing the poor thing! So I figured it was money well spent. Take care of it and it will get me home.

cruiser54

Having been around 4.0s since they came out, I'm quite comfortable with the operating temp.

twm3000

Both my hoses were 5/8 so all I had to do was remove the HCV and connect the hoses. HCV gone!

My vacuum line was already just hanging there. I capped it but there was nothing coming out of it.

DFlintstone

X2^, yes! what he said. As long as the AC is working, there will be no temp increase in the cab from the hot water circulating in the heater core. Agreed!

I'm not sure how eliminating flow through those little tubes help's them from clogging up with crud in the system? With the valve closed, bits of rust or silicone or whatever, won't even go there...one might think. (or not)

cruiser54

Think stagnation.......

And what are you doing up so early?