S3 Front knocking noise over 40mph

[W14FEN]

Hi Guys,
I have 2002 S3, 75k miles.

My car has developed a knocking / banging sound at speeds over 40mph, noticeable on motorway and country roads. It's not at low speeds or going over bumps like most banging noises.

It's quite faint and seems to get faster with speed.

It also gets louder with more passengers / weight. On my own it's practically not there.

It's got new tyres and just had cam belt done.

Any ideas most appreciated!

Thanks

Update: Just realised when I floor it in 3rd, 4th, 5th the car seems to lose power at 4000rpm...I can hear the turbo kick in but the car loses drive, after it sits at 4000rpm it gets going again, like the clutch is slipping or something. The clutch was heavy when i bought it, but there's no slipping when I pull away in 1st and 2nd.

Could it be the clutch or I read it could be the fly-wheel? Would that cause this banging noise?

 

[god_thats_quick]

For the banging noise, I'd check, ARBs, wishbone bushes, track rods / ends and the ball joints for play to start with.

From your description of loosing power, if the revs are stopping rather than climbing (without you going faster) then it might be your MAF / AMM whatever you want to call it. When mine went it would just hesitate then go at full power all of a sudden (however this wasn't at a particular RPM).

 

[W14FEN]

Hi eveyone,

5 months later and the banging developed into a 30mph+ drone / humming sound. Finally had something the local garage could diagnose. And well done to jeffers as it was indeed a wheel bearing!

I was convinced it was coming from the driver side front, but turns out it was the driver side rear.

The hub was quite damaged but didnt need replacing.

Thanks for all your help everyone.