Climate Control Flap
07-04-2001, 10:35 PM
#1
The V8 Porschephile
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Climate Control Flap
The past few days, I've been noticing a strange flapping-type noise coming from my center vent. Using a digital thermometer near the indoor dash-mounted temp sensor,I've managed to synchronize the noise to whenever the cabin temperature reaches the setpoint on the temperature control. I suspect that the air flap cannot decide whether or not to open or close once the desired temperature has been achieved. By moving the temperature selector 1-degree up or down will eliminate the noise temporarily until the setpoint changes. Has anyone experienced this and does this mean removal of the heater box as a fix?
Andy
'91 928S4 horizon blue/cobalt
Andy
'91 928S4 horizon blue/cobalt
07-05-2001, 06:50 AM
#2
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Dear Andy,
The flap drive is actually an electric motor being controlled by the heating/aircon control unit. It is modulating. Moving one way and the other regulating in the input of mixed air to provide the correct temp as per the selected temp.
The most common cause of this flapping is the motor is failing and it is no longer damped. Another cause is a bad connection on the motor.
The temp sensor can also be fluctuating and this may cause the problem.
Basically you will need to do some disassembly, get the motor/valve assembly out and check the inputs are not fluctuating. If the input drive signal is firm and steady then the valve assy is kaput. From your fault description I suspect the motor/valve assembly is the culprit. Try turning the temp control to full cold, see what happens and then full hot and see what happens,
Ciao,
Adrian
The flap drive is actually an electric motor being controlled by the heating/aircon control unit. It is modulating. Moving one way and the other regulating in the input of mixed air to provide the correct temp as per the selected temp.
The most common cause of this flapping is the motor is failing and it is no longer damped. Another cause is a bad connection on the motor.
The temp sensor can also be fluctuating and this may cause the problem.
Basically you will need to do some disassembly, get the motor/valve assembly out and check the inputs are not fluctuating. If the input drive signal is firm and steady then the valve assy is kaput. From your fault description I suspect the motor/valve assembly is the culprit. Try turning the temp control to full cold, see what happens and then full hot and see what happens,
Ciao,
Adrian
07-10-2001, 07:46 PM
#3
The V8 Porschephile
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Hello Adrian and thanks for the reply. I ran a test as you suggested and the noise did not come back (Full open/Full Closed). The flapping noise only occurs when the temperature is around 18-20*C as shown on the temp.selector.
Andy Evangelidis
'91 928S4 horizon blue/cobalt
Andy Evangelidis
'91 928S4 horizon blue/cobalt
Originally posted by Adrian:
<STRONG>Dear Andy,
The flap drive is actually an electric motor being controlled by the heating/aircon control unit. It is modulating. Moving one way and the other regulating in the input of mixed air to provide the correct temp as per the selected temp.
The most common cause of this flapping is the motor is failing and it is no longer damped. Another cause is a bad connection on the motor.
The temp sensor can also be fluctuating and this may cause the problem.
Basically you will need to do some disassembly, get the motor/valve assembly out and check the inputs are not fluctuating. If the input drive signal is firm and steady then the valve assy is kaput. From your fault description I suspect the motor/valve assembly is the culprit. Try turning the temp control to full cold, see what happens and then full hot and see what happens,
Ciao,
Adrian</STRONG>
<STRONG>Dear Andy,
The flap drive is actually an electric motor being controlled by the heating/aircon control unit. It is modulating. Moving one way and the other regulating in the input of mixed air to provide the correct temp as per the selected temp.
The most common cause of this flapping is the motor is failing and it is no longer damped. Another cause is a bad connection on the motor.
The temp sensor can also be fluctuating and this may cause the problem.
Basically you will need to do some disassembly, get the motor/valve assembly out and check the inputs are not fluctuating. If the input drive signal is firm and steady then the valve assy is kaput. From your fault description I suspect the motor/valve assembly is the culprit. Try turning the temp control to full cold, see what happens and then full hot and see what happens,
Ciao,
Adrian</STRONG>
07-11-2001, 11:38 AM
#4
Burning Brakes
Dear Andy:
Why do you care if your AC is working properly? Aren't the temps in Montreal cool enough for you?
Really, it sounds like you may have a small vacuum leak in the solenoid actuator. If and when you get the time, you'll have to pull off the center console to gain good acces to all the vacuum lines and actuators, and repair and replace as needed. I have to do the same. So far, I just push the AC button and drive around cold. So what if my mileage goes down by 10%?! YMMV.
Why do you care if your AC is working properly? Aren't the temps in Montreal cool enough for you?
Really, it sounds like you may have a small vacuum leak in the solenoid actuator. If and when you get the time, you'll have to pull off the center console to gain good acces to all the vacuum lines and actuators, and repair and replace as needed. I have to do the same. So far, I just push the AC button and drive around cold. So what if my mileage goes down by 10%?! YMMV.
07-16-2001, 03:38 PM
#5
The V8 Porschephile
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Funny you mention that Ed. Many years ago,a few inmates from a midwestern state prison escaped and headed up north to seek refuge in Canada. They were eventually caught and were found in a semi-dehydrated state due to the heavy equipment that they were carrying(Parkas,snowshoes,boots,mits,hats,etc..) in the month of JULY!!!
Yes we have cold climate up here in the winter but our summers are long and hot!!
When I have the chance on removing my console, I'll probably tackle the actuator thing. My philosophy (greek that is) is that if it works, don't mess with it!!
Andy Evangelidis
'91 928S4 horizon blue/cobalt
Yes we have cold climate up here in the winter but our summers are long and hot!!
When I have the chance on removing my console, I'll probably tackle the actuator thing. My philosophy (greek that is) is that if it works, don't mess with it!!
Andy Evangelidis
'91 928S4 horizon blue/cobalt
