napa heat control valve
09-21-2011, 10:33 AM
#61
Rennlist Member
I'm with Alan on this issue..
Personally I continue to use the stock valve - mostly they seem to be OK - need periodic replacement - but I expect all types will.
For those of you with permanently off water valves: petcock, wired shut - whatever... you do realize you now really have no temperature control at all...?
In AC mode the AC is always on (unless the evap freezes) and the only way temperature is controlled is by opening the water valve and mixing. Without the ability to open the water valve the only way to regulate temperature is with the blower fan and AC switch - e.g. modulate AC on/off and or reduce the air flow (maybe recirc/vs fresh too) - in any case very manual.
If the system is working effectively the AC should eventually get you uncomfortably cold air blowing on you - it certainly does for me even in Phoenix in summer - it may take a while - but on a long trip and especially out of town - I'd eventually want to be able to warm up that airflow to a comfortable temp. So for me a permanantly closed valve just wouldn't be a good idea.
Alan
For those of you with permanently off water valves: petcock, wired shut - whatever... you do realize you now really have no temperature control at all...?
In AC mode the AC is always on (unless the evap freezes) and the only way temperature is controlled is by opening the water valve and mixing. Without the ability to open the water valve the only way to regulate temperature is with the blower fan and AC switch - e.g. modulate AC on/off and or reduce the air flow (maybe recirc/vs fresh too) - in any case very manual.
If the system is working effectively the AC should eventually get you uncomfortably cold air blowing on you - it certainly does for me even in Phoenix in summer - it may take a while - but on a long trip and especially out of town - I'd eventually want to be able to warm up that airflow to a comfortable temp. So for me a permanantly closed valve just wouldn't be a good idea.
Alan
Now that I have my AC working effectively with a clean evaporator and new intake filter installed (as originally designed) it can get uncomfortably cold at times and the ability to blend in some hot air in to that airflow allows me to be comfortable inside the car at any time.
A permanant closed valve will not let you do this it's only a work around method for a system that's not working as it should.
09-21-2011, 10:35 AM
#62
Rennlist Member
Just my $0.02
Jerome
09-21-2011, 10:49 AM
#63
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That it can be ice cold yet in stock config is not - implies the water valve turns on when it shouldn't and maybe that the comb flap doesn't work right.
If everything works your AC should be too cold for comfort on any decent length run...
Alan
09-21-2011, 11:53 AM
#64
Rennlist Member
Alan,
I immediately get ice cold air because my summer HCV is modified with a tie wrap to keep it fully closed. And you're correct - my comb flap doesn't work. I cut and capped the line a while back. I have all of the diaphrams I need to repair the leaking vacuum pods.
I know I have vacuum leaks and maybe a bad vacuum solenoid or two. I have Wally's and Dwayne's procedure for the HVAC system but unfortunately was not able to go through everything as I should. So the modifications were necessary to survive this year's blistering summer heat. There were many weekends when I wanted to go through the HVAC system but it would be well over 100 degrees in my garage!
As for the A/C temperature - yes it can get very cold in my car - but I'll take that over luke warm on a 105 degree day! The fan is almost always on the lowest setting. As with most upkeep items, I prioritize based on importance. This summer it was more important to have really cold air in my daily driver, even if it meant having a system that was not operating like it did when the car was new.
I immediately get ice cold air because my summer HCV is modified with a tie wrap to keep it fully closed. And you're correct - my comb flap doesn't work. I cut and capped the line a while back. I have all of the diaphrams I need to repair the leaking vacuum pods.
I know I have vacuum leaks and maybe a bad vacuum solenoid or two. I have Wally's and Dwayne's procedure for the HVAC system but unfortunately was not able to go through everything as I should. So the modifications were necessary to survive this year's blistering summer heat. There were many weekends when I wanted to go through the HVAC system but it would be well over 100 degrees in my garage!
As for the A/C temperature - yes it can get very cold in my car - but I'll take that over luke warm on a 105 degree day! The fan is almost always on the lowest setting. As with most upkeep items, I prioritize based on importance. This summer it was more important to have really cold air in my daily driver, even if it meant having a system that was not operating like it did when the car was new.
09-21-2011, 12:59 PM
#65
Electron Wrangler
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Well - really the good news is you know that the basic refrigeration loop works pretty well - just the water valve & vents (maybe vacuum). Is the comb flap fixed in the "bypass mode" - air direct to the console vent via the evaporator - that would get you the best cooling. I believe default (no vac) is non-bypass
Alan
Alan
05-23-2012, 10:36 PM
#66
Captain Obvious
Super User
Super User
I think this is what Roger is referring to- it's an exact
fit- just uses a cable. If you don't want/ need the blend
feature of the vacuum one this should do it.
http://www.autopartsnetwork.com/imag...1630166TKU.JPG
fit- just uses a cable. If you don't want/ need the blend
feature of the vacuum one this should do it.
http://www.autopartsnetwork.com/imag...1630166TKU.JPG
05-24-2012, 04:19 PM
#67
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part number is 944 572 085 02 we sell for $24.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
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928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
