Engine Light - possible coil pack failure

[arkturas]

Whilst driving home this evening, my S4 shuddered a little whilst accelerating. Immediately the engine light came on, it sounds & feels like its running rough with loss of power.

I suspect a coil pack has failed. my local euro car parts has some listed about £33 each - so hope to pick one up tomorrow.
if I replace the coil pack will I need to reset the fault using vag-com or similar. I have an old version but not sure it will work (it worked on my old 25th Golf Anni) - I don't really trust it on my S4.

Is their an easy way to test which coil pack has failed, I read somewhere that fiddling with packs can also cause more to fail?

[xyber]

If you vagcom it you'll get two codes normally

Random misfire detected
Random misfire detected cylinder X

You don't really want to touch any other coil packs if you can help it and get ready for others to fail as well.

Worth getting a £40 fault code reader and keeping a spare coilpack and tools in the boot. Then you can swap them quickly and avoid fuel breaking down the oil

Your vagcom should be ok for the basics like this

[arkturas]

Thanks Xyber -
could you recommend any fault code readers ? - will this allow me to reset any error codes.
I still need to find my old vag-com clone cable /ebay home brew. It defiantly sounds like one of the right banks (offside) is misfiring, but I have no idea which one.

[xyber]

I keep on of these in the car http://www.gendan.co.uk/product_GDVAG.html for basic quick check ups and have fully VAGCOM for in-depth stuff

That scanner has sub menus like engine, abs, gearbox etc for basic fault finding in a few modules. Has a reference code book and a code disc and is powered from the diag port itself and can reset the codes

[arkturas]

After phoning around managed to find a specialist in Milton Keynes that could change the coils on short notice.
vag-com identified errors with coil packs 4 & 5.

Technician at DS Motors advised that the plugs also be changed as a matter of course.

Failed CP's :
Part Number: 077 905 115K
BREMI 12455ESM

- L2 A71D 6 15/05
- L2 A68B 6 15/05

Just noticed that visually the new coil packs are different to the originals. The old CP's have a flat head, whilst the newer type is slightly convex/recessed.

[aligod78]

I think this might apply too mate:
http://www.rs246.com/index.php?name=PNp ... ic&t=89419

[arkturas]

Thanks frustratingly this morning I ran into a another cylinder suffering a misfire this time number 8, I have just had coils & plugs on cyl 4 & 5 replaced. I drove straight to my local specialist and got all the remaining coils and plugs replaced. - pockets 400 Quid lighter
Ill give Audi a call to find out if there is any chance in reimbursement on parts. (cross fingers)

[aligod78]

Good luck. Have lost 4 so far since ownership, 6 months.