Intake manifold flaps knock

A6 All/ S6 All
#1

Hi,

My fairly new intake developed a flap knock on when flaps set themselves on long runner setup. The IM has about 35 000 - 40 000 km on it, so not too much. It is the M revision one, made in October 2017. I looked inside the IM with a camera and all flaps work flawlessly, and I have pinpointed the problem to the flaps having a tiny bit of front-back axial movement. Any ideas on this?

Thanks.

#2

Hi Dlug it’s not super uncommon for that play. Depending on how much but it’s not out of the range of normal

#3

I’ll try to post a video of the sound, but it does sejm pretty loud unfortunately.

#4

Curious at what RPM the flaps are moving? Is this a fixed setting or does it depend on throttle load?

Can hear the noise from inside the car?

I also updated the manifold on mine a few years ago and have had a hesitation at about 3800-4000.

I’m getting ready to start chasing this and wonderning if this might be flap related.