RPetty2

How hard is it to change the heater control valve? This is a new part to me ,and have a new one to put in, anyone have steps and pointers for me? Thanks Ricky racer jr

Avar928

Pretty hard actually. Very time consuming.

First you have to take out the air box and the MAF and then...oh, wait...that's it...because it's right there underneath the air box on the passenger side near the fire wall.

I have an early '86 and it literally took me 10 mins, and just that long because I kept rinsing the draining coolant out with water.

Make sure to replace the short hose as well with the heater control valve. I'd get a small bucket that you can squeeze in to the space to catch the coolant that WILL pour out once you loosen the clamps. Probably about 300-500mL I would say comes out. If your fine with the some coolant just draining down to the floor, you should be okay.

Everything was a no brainer. Check coolant level. Loosen, loosen, loosen. Catch the coolant. Remove. Replace. Tighten, tighten, tighten. Check vacuum. Check coolant level. Start her up. Run heater on high. Check coolant level then add the difference.

Oh, and never start her up to get her warm then shut her down, wait 15mins and then work on her. Not enough time for cool down. I made that stupid mistake (Oh, yeah, it's probably not THAT hot...) and when that coolant hit my hand...Probably should have waited another 30mins when I couldn't even touch the manifold cause it was so hot.

WallyP

Ricky,


Be sure that the black side goes toward the head. Look inside the new one, and see how it works. If you put it in backwards, the little gate inside can be pushed off of the opening, allowing hot coolant to flow even when the valve is closed.

GeorgeM

If you drain the resevior before you start, the leakage when you remove the hoses and valve will be minimal.

Tom in Austin

Allow a couple of minutes to curse Porsche for making such a flimsy POS part ...

jeff spahn

I thought someone made a metal one that was really nice?

Jerome Craig

Actually, if you open the reservoir and let the pressure out, then close it back you will only lose a few ounces of coolant. Opening the cap releases the pressure and tightening it back doesn't allow much air to enter the system when you take the HCV out.

RPetty2

Ok thanks guys!!

Maleficio

Verify that you have a vacuum signal at the hose first by cranking up the heat.

MainePorsche

Ditto.
Very important to put it on correctly, as it is all to easy to put it on the wrong way.

jej3

Heater control valve, we don't need no stinkin' heater control valve. I was happy to buy a NAPA petcock and close that off permanently. If I am some place cold in my 928, I've gone too far in the wrong direction

MainePorsche

You never know. It is always good to have the option, especially when you need it.

Maleficio

If you need heat, open the petcock.

kevin2012

Sorry to use this thread. I had removed everything and forgot to take a picture.
There are 2 metal tubes from the heater core, upper and lower. Which one should connect to the heater valve? Thks

Tom in Austin

Lower hose is input to the heater core and connects to the valve.