Socal_Tom

Then it appears I don’t know how to use zip ties? There shouldn’t be any heat at the interior air vents if that heater valve is closed, correct?

OR, is there another heater valve failure mode where even if closed the valve let’s coolant past?

Thanks gentlemen, hope you all are having a good weekend.

Speedtoys

Was it a new valve?

928 GT R

Because Germany is a cold climate, all faults/defaults in the system are set to provide heat. It can be a number of things including a faulty heater valve or one that was installed backwards.

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Socal_Tom

Hi – thank you for the fast response. It is not a new valve, my guess is it’s original to the car.

Socal_Tom

Interesting. It looked like the orientation was correct from the other pictures I’ve seen but this is my first time digging into this part of the car.

Alan

Valves can also fail open (well - partly open) - pretty much has to be that - I'd just get a new valve

GregBBRD

There's an O'ring that seals the door. If it gets displaced, water will leak around the door.

mkhargrove

are you sure the heat is from the heater valve? is it possible that your "fresh" air flap is open? this time of year (in Texas), that flap will nullify what an air conditioning system can otherwise do. it pulls hot air from outside and runs it through the evap coil. it might feel like the heater is on.

if you look under the dash below the glove box, you'll see the access to the blower, etc. you'll also see in the center, a square hold about 1/2 inch by 1 inch. push your finger up in that hole and you can feel the fresh air flap. you'll be able to tell if it's open...you can push it closed. if your actuators/vacuum is bad, it's going to stay open. and if that's the case, get creative. I rigged a piece of a coathanger as a brace to hold mine closed. it probably made a 20 degree difference in the air temp coming from the vents. maybe more.

FredR

Tom,

Just to eliminate the obvious- presumably you understand that when no vacuum is applied the valve is open? If you want to wire the valve closed it is no problem but you should disengage the actuator arm and pull it fully upwards towards the actuator. This alone will keep the slide in the closed position- wiring it secures it of course.

For your further info the valve is unidirectional and to form a seal when closed it will relies on the differential pressure the pump generates [not much] and a spring to push the slide plate onto the sealing surface. Mount the valve the wrong way and I doubt it will seal as the water pump developed head will then try to push the gate open against the spring pressure. That being said if the valve were mounted incorrectly I doubt the flow would be sufficient to cause a major issue but that is just a scientific guess- clearly any flow of very hot water is undesirable given the desired intent.

Socal_Tom

Thank you for all of the responses, very helpful and I appreciate the support. Let me do some more investigation today and report back. Thank you for all of the responses, very helpful and I appreciate the support. Let me do some more investigation today and report back. Thank you gentlemen.

Tony

I have two pieces of string tied to the arm on mine...pop the hood and pull it one way it’s open...the other it’s closed. I rarely if ever use the heat here but I still like to keep fresh coolant in the heater core. If also placed aluminum foil tape over the vent where the air departs the heater core in side ..also have a direct vacuum line to the recirculating flap so it’s always shut (drawing cabin air)...need all the help I can get here in the summer and never have to de fog the windshield anyway.

hacker-pschorr

Are we taking warm air or super hot air?

Even with a fully functioning heater valve tied shut, the heater core still gets very warm. The return line is still connected to the engine without any valve and that coolant will get warm.

If the blend door is broken or stuck in the "hot" position, this warm heater core will push warm air into the cabin.

The recirculating flap mentioned above can also be an issue. I also discovered with my HVAC vacuum pod R&R that if the comb flap is "stuck" in one position you'll get somewhat warm air out the center vent.

Socal_Tom

Good morning, hope everyone had a good weekend and I appreciate all of the responses.

@Hacker-Pschorr - the air is warm but not super hot. My HVAC system is FUBAR (to put it mildly), and my immediate goal is to stop the heater core from leaking / leaking into the cabin.

After a quick run around the block yesterday I was getting warm air from the vents, which I didn't expect, but I didn't see any coolant leaking on to the driver side floor like before.

hacker-pschorr

Buy something like this and pinch off the return line:

https://www.harborfreight.com/4-piec...set-65116.html

Bill Ball

I discovered that my RV, which is based on a 2003 VW Eurovan chassis, does not have a heater control valve. It relies solely on the blend door to seal off the heater core air. Strangely confident that this would be enough (and it appears to be), whereas Porsche seemed to be using a belt with suspenders approach.