Exhaust flaps & noise

[leont]

After reading several posts on here about the exhaust flaps I tested them earlier. The flaps stay closed at all times, S button on or off. I even got the missus to give it some revs while I watched the flaps (and near choke me to death!) and no movement at all. I'm assuming there is a vacuum issue or maybe the flaps need lubricating.

The thing is when I'm driving the car and press the S button it definitely gets more vocal. I tried it yesterday on the motorway and instantly my passenger picked up on the extra noise (sounds fantastic).

Does this sound right? I had naturally assumed the flaps were in working order because of the noise with the S button on?

[adsgreen]

The flaps only open at idle.
After that there's some very strict rules in sport mode that dictate when they open.
Something like closed unless
- idle engine speed
- over 3k rpm
- 4th gear or higher
- over 30mph

[Ice_Coffee]

The flaps only open at idle.
After that there's some very strict rules in sport mode that dictate when they open.
Something like closed unless
- idle engine speed
- over 3k rpm
- 4th gear or higher
- over 30mph

and the whole lot does not turn on until the 7000RPM MAX sign has gone out !

67Deg C engine oil

[leont]

I took it for a run first so the 7K limit was gone - engine oil was in the 70's. Flaps closed when idling with S button on/off. What is confusing is the car is noiser when driving about with the S button on. Its as though the flaps work at speed, but not at idle. Unless there is another reason for the extra noise at speed with flaps closed?

[PetrolDave]

The flaps stay closed at all times, S button on or off.

At normal tickover rpm, even with a cold engine, the flaps should open when you press the Sport button and the exhaust noise will increase.

If they don't then IMHO that indicates a vacuum problem and/or stuck actuators.

[leont]

The flaps stay closed at all times, S button on or off.

At normal tickover rpm, even with a cold engine, the flaps should open when you press the Sport button and the exhaust noise will increase.

If they donThanks - I'm going to lubricate them try tomorrow, next step trying the mod to keep them open at all times.

I've probably not been that clear in my post. What confuses the issue is that (assuming the flaps are closed permanently) why I get the extra noise when I press the S button on the move. If the flaps are closed where is it coming from? Is it just extra induction noise coming through from the air intake flap?

[adsgreen]

Perhaps more vacuum available when the engine revs are higher??

[neckarsulm]

Perhaps more vacuum available when the engine revs are higher??

good point

At normal tickover rpm, even with a cold engine, the flaps should open when you press the Sport button and the exhaust noise will increase.

This is definitely correct as I have tested mine hot and cold when Birmingham Audi told me they were defective,£782 please (the tw4ts were wrong)

[aidanjaye]

Perhaps more vacuum available when the engine revs are higher??

good point

At normal tickover rpm, even with a cold engine, the flaps should open when you press the Sport button and the exhaust noise will increase.

This is definitely correct as I have tested mine hot and cold when Birmingham Audi told me they were defective,£782 please (the tw4ts were wrong)

Agree - even stone cold - press S button and flaps will open and exhaust sounds deeper.

[Ice_Coffee]

In that case I stand corrected

[ShaneyB]

I thought 'S' mode was compulsory

[Timster]

Remember also, that if you have the 090 firmware... the initial revs will stay higher for longer, until they drop back to idle.
And as others have said.... it's not until they drop to idle, that the flaps will work (hot or cold).

Any joy yet?

[aidanjaye]

Remember also, that if you have the 090 firmware... the initial revs will stay higher for longer, until they drop back to idle.
And as others have said.... it's not until they drop to idle, that the flaps will work (hot or cold).

Any joy yet?

Emm , dont think so.

Car running 09 firmware - coldstart, press S button on/off even when revs are up and you can here the flaps opening and shutting (engine tone).

[Timster]

Erm, Yes so.

Start the car from cold ~ whilst engine still idling above 1k rpm ~ run out the back of your car (with torch if necessary) and check flaps. They'll be closed. Now press "S", you'll get plenty of other noises and rumblings (seat bolsters moving etc).... the flaps will still be closed however.
Wait a few seconds until the engine dies down too 800 rpm ish. Try the same ~ flaps will open and close with "S" button.

[neckarsulm]

aidanjaye, Timster is correct, it has to be the normal idle speed for the S button to open the valves.

However, there is a noise, a bit like a repetitive clicking which someone says is unburnt fuel related, I have checked my exhaust flaps when it does this and they are closed still