I am the new owner of a 2010 A8L with sport package and the bang & olufsen sound system, Midnight Blue Pearl Effect over Black Leather interior. I'm very happy with the car overall but I have a mystery ticking/tapping/almost knock sometimes. Some days it'll start up ice cold and it doesn't make a peep and others the noise will be there immediately and then fade a bit after warmup. Initially I assumed timing chains/tensioners but it doesn't make sense to me that it would come and go. There is a lot of clatter/noise that seems to be coming from the intake (going to pull it off and apart to confirm all flappers are in place and functioning properly).

Any insight from anybody? I've done some extensive researching here on the forums and other places on the net but can't seem to find anything definitive... I've just ordered a rosstech vcds but as of yet have no way to scan codes. The car has just over 200,000kms but is in impeccable condition inside and out, beautifully built piece of machinery but man is it complicated when you begin to dig into it.

This site has already been a wealth of information.

The air suspension works perfectly, no issues with raising and lowering and no warning lights for the suspension. I do hear a slight noise rolling over speed bumps which I am assuming are the upper control arms on their way out.

The noise is is quite often there so it's easy to get under the hood to try and locate it but I can't specifically find the source. I would think if the timing chain were shot at the back of the engine that the sound from it would be very easy to find with my ear back at firewall. I've been doing a lot of reading about all of the flapper valves inside the intake... I am thinking that possibly one of them has broken free and is possibly sitting on top of the intake valves causing the noise.

I also love the wheels. I had some gun metal grey winter wheels (knock off rep wheel of the same design) on and it didn't even look like the same car.

It has no issues with driveability or performance, it runs perfectly other than the racket it makes here and there. I'm not daily driving it now until I can sort out the source of the sound.

I have owned and personally wrenched 160+ vehicles so I thought I'd seen and heard pretty much it all but this has me a littlene stumped???