Airbox flap not working.

[RS4FTW]

Hi

I used VCDS last night to test and my airbox and manifold flaps and the manifold flaps are working 100%. However the airbox flap opens but doesnt close. I can hear it trying to close however that doesnt happen. Should it be closing when i use VCDS ? It was definetely closed when i started the test so not sure what is going on.

If it was staying open, what would the consequences be ?

TIA

[neckarsulm]

http://www.rs246.com/index.php?name=PNp ... highlight=

My own thread but even I found it interesting to reread it!

[RS4FTW]

http://www.rs246.com/index.php?name=PNp ... highlight=

My own thread but even I found it interesting to reread it!

Thanks for that. Very interesting so it seems the flap staying open isnt good at all. How did you fix yours ? I suspect the spring on the flap might be screwed

[Terry1948]

My power flap has just has been replaced also the solenoid, which was not working either. Now when you test it using Vagcom it works text book fashion. My thanks to Silver RS4 for his excellent article on how to perform this test. Ipswich audi did all the work under warranty managed to get a tech that understood what was required. Will try it out this weeekend

[neckarsulm]

Strange how they replaced both? Maybe they misdiagnosed it?
The solenoid is operated by a signal from the ECU, when its operated it allows vacuum to be to the flap diaphragm to open it.
If you replace the flap and it still doesn't work then it's the solenoid and vice versa but unlikely both were defective.
Easy enough to test with VAG COM, undo the vacuum hose from the flap diaphragm, run the output test and see if you can feel vacuum at the end of the hose.
If it's stuck open I'd say that it's the flap catching the body of the unit and is fixable, if it's stuck shut then something is wrong.
TBH I am surprised these are actually going wrong to the point that they have to replaced, is the new flap modified to stop it sticking open? Mine worked OK but would every so often stick open due to bad design.

[Terry1948]

Solenoid was not working. When replaced and tested the power flap would open but not close, so to keep me happy replaced power flap. The flap would open and shut okay if manualy moved. It is good to see audi doing the decent thing and not trying to get away with the cheapest option

[neckarsulm]

Terry, I was asked to fix a non-op flap today.
Ordered new air box base with flap and the solenoid valve fully expecting to return 1 or other back to Audi.
Checked solenoid with VAG COM, completely dead, slotted in new one, away it clicked.
Connected it to old air box and flap and it moved but it was a bit limp to say the least.
Connected it to new flap and it was perfect doing the 90 degree open to close test procedure.
I suspect the defective flap had overworked the poor solenoid valve

[lengster1]

How much are the solenoids? Mine never got sorted at mrc so will have a look myself me thinks with vagcom.

[neckarsulm]

I think they are around £50, air box base around £60.
Take air box base out and you can see it.
Luckily it just slides off the bracket and you can bend the bracket to get it back on and then push it back into place, quite an unexpectedly easy location to work on unlike the similar N75 valve on 1.8T and 2.0TFSI A4!

[lengster1]

Thanks,you dont have the part no do you? At that price il order one for when i get back to uk

[neckarsulm]

Let me check on Monday, if you want me to post you one for same price as Audi counter price I can.