OverBoosted28

Twilightblue28A

No, but please see what I have done in my response to OverBoosted28 below. Thank you. I am open for suggestions.

Twilightblue28A

OverBoosted28,
I doubt that the temperature difference is coming from the rear of the car because I recorded 160f temperatures from the driver and passenger front heater hoses within five (5) minutes of starting the car. I disconnected the heater hoses from the servo motor/mixing valves when I recorded the 160f temperature. I also verified that both servo motor/mixing valves inside the cabin were operating correctly. I checked all of the paper hoses to ensure that they were securely attached and not leaking. The temperature is less hot on the driver's side compared to the passenger's side. The temperature variance is significant comparing the recordings as follows:

Temperature data is as follows: temperatures recorded at heater hoses within five (5) minutes of starting my car. The temperature gauge on my instrument panel wasn't registering any difference until my car idled longer. All of my car's temperatures were taken with my car idling. (My car wasn't moving)

Driver's side heater hose (disconnected from the servo motor/mixing flap 160f.)
Driver's side defrost 128f.
Vent 118f.
Feet 116f.
Center vent 128f.

Passenger's side heater hose (disconnected from the servo motor/mixing flap 160f.)
Passenger's side defrost 138f.
Vent 144f.
Feet 160f plus.
Center vent 128f.

Temperature control set to the red dot. Fan set to maximum (4). Please notice a significant temperature difference comparing the driver's side to the passenger's side temperature recordings.
The temperature recordings at the vents were recorded when my car reached normal operating temperature, idling, and my car not moving.

I feel I have chased this down significantly and I welcome any positive, constructive advice.

Also, have any other owner experienced what I have described, and if you have, how did you repair the issue.
Thank you.

Meenrod

​​​​​​My suggestion remains the same as it did several months back. You'll recall I had the same problem which was diagnosed the same day by my mechanic running an OBD diagnostic and pulling the fault codes. Thus the 2 actuators that had failed were removed and refurbished and are now reinstalled in the vehicle. I suggest you run a diagnostic - I suspect it will save you a lot of time and effort.

Twilightblue28A

Thanks Meenrod,
I was ready to buy a Durametric from someone on the site and I was beaten to the punch. I will have to buy one directly from Durametric's. The Porsche Dealer in my area charges $150.00 to admit the patient, plus approximately $300.00 for the scan, before parts and labor. That's why I have been hesitant. Regarding the sensors that you mentioned that you replaced in your car. Are the sensors you replaced in your frunk?
I know this is time consuming. It serves as a distraction to the stress I experience daily and also represents a challenge compared to Oldsmobile 442 repairs. Thank you!

Meenrod

Don't take it to a dealer - use a Porsche OR a German Car specialist.
​​​​​​
Again, as I said before in one of your other threads and in a lengthy PM conversation with you- the fresh air servo and a mixer servo both accessed from the front trunk were faulty on mine.

Twilightblue28A

My heat is hotter on the passenger side compared to the driver's side.
I'm ready to order the Durametric's OBD Scanner.
Does anyone know if the Durametric Scanner can determine a faulty temperature sensor P/N 964.659.901.00 or the electrical connected to the temperature sensor sensor?
If Durametric's Scanner cannot test for a faulty temperature sensor, anyone familiar how to troubleshoot and test the sensors?
Thanks.

Twilightblue28A

Filter comparison.
This issue started with my car suddenly not delivering heat at hiighway speeds. The slower I drove, the more heat I received.
The driver's side was not as hot from all of the vents compared to the passenger's side. The air velocity from all of my vents on the driver's side was also less than the passenger's side regardless of idling or at highway speed.
I sent my fresh air servo motor to PARTisan for rebuilding.
While I was waiting for the fresh air servo motor I checked both mixing valves and both operated properly.
I disconnected the heater hoses, both sides, before the mixing valves and I received high temperature recordings.
I reconnected the hot air hoses to the mixing valves and I received high temperature recordings both sides.
I checked all of the paper hoses after the mixing valves for leaks and to confirm they were all securely fastened, and they are.
I installed the rebuilt servo motor yesterday and took my car for a test ride. At highway speeds, the passenger side was blowing hot air, with strong velocity. The driver's side was not as hot, and the velocity was not as strong as the passenger's side.
Tonight, I changed both particle filters. With the car idling at operating temperature, and the heat set to maximum, I removed the passenger's side filter cover. I felt sufficient air volume, but no heated air. The driver's side was hot.
So I have two issues. The driver's side won't blow heated air and tthe velocity is not equal to the the passenger's side.
Any other members experience anything similar?
Any members have any ideas to correct?
Your help will be appreciated.
Thank you

Churchill

Have you checked the orange silicone ducting under the engine and the aluminum air diverters they connect to?

Twilightblue28A

Thanks Churchill,
I don't have a lift so I haven't checked under the car. I can see the hoses are secure to the heater boxes. I'm recording temperatures in excess of 160 degrees from the heater hoses on the driver and passenger's side as they enter and exit both sides mixing valves. Both fans are working. The driver's side fan is not discharging heat. Something may be happening downstream of the mixing valves?

pp000830

Things to check:

• Rubber hoses as above on both ends of the air diverter (flap housing) are attached and secure;
• Check the flap in the vent on the bottom of the air diverter (flap housing) that it moves freely and can close, not a precision fit.
• Test the driver side temperature sensor near the blower in the frunk with an ohm meter when cold & warm to test its signal OR
• Consider looking at the two footwell servos and see if they are in the exact same (open) position, while not detached from their hoses and while running the heat. Do this by setting the CCU to the coldest setting, shut off the car and make two identically positioned strike marks across the end of each servo/actuator's metal shaft that protrudes through the top of the actuators housing using a Sharpie-Pen. When powered this shaft will rotate and with it your strike marks to indicate the servos' movements & positions. you may need a small mirror to see it clearly.
• My understanding is that there is an additional flex hose where the rear metal duct pipe attaches to the body that can be cracked or disconnected.

If you can't see this the diverter housing go to any shop and ask them to put your car on a lift so you can take a look or bring this list with you and ask them to look.
Andy

Blue Ocean

Interesting that you are receiving high temp on both downstream side of the mixing valves. Are the temp readings the same?

Was this about the same as before any of your work?

This has me confused, as you have been receiving more hot air from the passenger side. I would think you would have had sufficient air volume and heat from the passenger's side, but NOT the driver's side.

Maybe there is some kind of obstruction in the driver's side duct between the vent and mixing valve?

Twilightblue28A

Blue Ocean,

With particle filter covers off, and the temperature set to maximum, I am getting good velocity of air from both fans, except the passenger side blows hot air and the driver's side only cool air.
I also disconnected the heater hoses from the mixing valves and recording in excess of 160 degrees from each heater hose. I checked all of the paper hoses to under the dash and all are secure and not leaking.
I also checked both mixing valves and both open and close depending on the temperature settings.
Might be time to put the heater levers on the floor like my '77 and '85...lol
Meantime this is driving me nuts.

ToreB

Twilightblue28A, this is your sixth forum thread on this topic.
I understand your frustration, but it could be a good idea to limit this to one thread so other members can see what already has been adviced and done on this.

I haven't been able to read all your posts in all the threads, but have previously sent you advice and asked you these questions:
Have you done a OBD diagnostic readout on the CCU? You might have a faulty mixer sensor or other problem.
Have you inspected the rubber flaps in the heat exchangers, do they behave in the same way when poking them? A damaged flap might let out heated air when in motion and when the rear fan is operating at full speed.

Cheers,
Tore

Churchill

OP, if you're getting equal amount/velocity of hot air at the heater hoses in the footwells, then trace the path of the air from there and see where it stops staying hot.

Agree w/ Tore -- too many posts on this, and you don't seem to want to do real diagnostic work.