......Maybe the chain? Mechatronics unit? Gearbox? Anything?

[BigWillyStyle]

Ok my car is a 2004 A3 2.0 S-Line,

As a few of you are aware my car is having a few engine troubles (Misfire starting when engine warm, Juddering at low revs and struggling to change down gears).........

Well, obviously when you have all of these problems you try to listen to the engine as close as possible so when you take it to a garage you can tell them and hopefully help diagnose the problem.

When i accelerate i've noticed a metal/chain sounding noise getting louder then when i decellerate it makes clunking noises as it changes down gear (Car being auto/tiptronic/paddle shift).

I was just wondering if any of these problems could be resolved if the chain was changed and/or if anyone can offer me help in diagnosing the problem or had any issues like this too.

No fault codes or engine management lights come on.

Going in for a full service on Sat so wondering if this could cure any of the problems.....

 

[JPK]

Presuming its a non turbo FSI with Multitronic gearbox. It doesnt have a 'mechatronics' unit, its called a Transmission valve body in those and around 4 out of 10 fail from what I understand with the symptoms you describe - horrible units. Replace that (probably around 1000GBP) and you should be right on the gearbox sounds (clunking/metallic noises).

The clutch packs MAY also need replacing if you have been driving it in this state for some time.

Not sure on the missfire when warm. Get fuel and ignition system tested to start with. Then start looking at all the valves that relate to emissions.