My brother bought a 53 reg A3 2.0 FSI about 4 weeks or so ago and since getting it he has said that it is hesitating on acceleration and its been back to the dealer about 3 times. They've replaced the MAF, fuel banjo bolt and camshaft chain tensioner amongst other things but it hasn't sorted it and they've now given up saying they can't feel it or find owt wrong.
I picked it up today from his house and gave it a drive and it was fine. I did a couple of non engine jobs on it (cleaning inside etc) and then because the dealer for no reason mentioned a loose coil pack I removed them and had a look, nothing obvious so I replaced them and noticed a vacuum hose that had been rubbing and had a weak point so I replaced that. I then went out in it and it was fine for around 3/4 of a mile and then when accelerating not too hard the engine coughed and the engine light came on and I had to limp it back home. My diagnostics machine showed a misfire on cylinder 3 and also a random misfire problem. I messed around moving the coil positions and changing the plugs around and kept getting the random misfires code and the engine is misfiring on tickover. I now have it where the machine shows a misfire on cylinder 1 which indicates a coil pack problem to me as it was on 2 originally and I believe these are problematic.
I just wondered if anyone had any experience of this or any suggestions as to other likely causes. I kinda feel guilty as the car broke on me but I didn't do nowt other than inspect the coils in the first place.

Are they individual coils or one pack? If its individual, is it the same one misfiring?

Individual. The candlestick affairs. This is the thing. I moved the coil off cylinder 2 and onto 3 but the problem still stayed on cylinder 2. I changed the plug but the problem stayed on cylinder 2 and now I've juggled them all about in a fit of anger and the problem is showing on cylinder 1 now. Confused as to why it's behaving irrationally and also why should it just go all of a sudden like that, presuming it is a coil pack problem.

Hmmm. Are the wires ok? Could there be a short somewhere?

Possibly, but why should it go all of a sudden and they're all in a conduit affair that I can't really mess with as the car has a 12 month warranty I believe and it'll have to go back again but it's just annoying me sat on the drive broken!

Misfire codes often don't point to the correct cylinder.

Coil pack & plug should always be replaced together, if the engine has a short lead between the plug and the end of the coil pack that should also be replaced.

One of the main causes of coil pack insulation breaking down is long plug change intervals and wide plug gaps.

Interestingly from the NGK catalogue Audi specified a 1.1mm (0.044" plug gap for the 2litre FSI A3 but for the 2litre FSI Turbo the gap is specified at 0.8mm (0.032" on a slightly cooler plug.

quote:

---

Originally posted by mistergrumpy
Possibly, but why should it go all of a sudden and they're all in a conduit affair that I can't really mess with as the car has a 12 month warranty I believe and it'll have to go back again but it's just annoying me sat on the drive broken!

---

Well the dealer was supposed to have changed the plugs before the car was sold. They look okay but not 4 weeks new imo. The gap was probably right thinking about it.
So far they've been quite good in all honesty and they're valeting the car every time it goes in but from my past experiences with dealers, I tend not to trust them and prefer to look after my car myself. They'd better not try it on with a serviceable parts argument or all hell'll break loose if my mum finds out

Weren't the coils on plugs a big problem on Audi's a while back. Basically a design stuff up which caused all sorts of problems. I would have thought most of them would have been changed by now.

It got to the point where the service guys carried boxes of them in their vans, back in 2002. I remember my sisters brand new TT outside my house with the engine warning light on, and I told her it was the coil pack without even opening the bonnet (or the front door). The service guy came and fixed it, and she now thinks I really know things about cars (how little she knows).

Perhaps take it to a different Audi dealer. There are loads and perhaps the present one isn't the best. They are only people.

Matt

Yep I now believe they were a problem. Thing is now, the service dept. not open tomorrow and will be Monday now before the car can go in and then it's got to get there. I might try the scrappies for one tomorrow. At least if it see's him through the day and so he can get it in Monday evening then it's a spare.
Still odd why it just gave up all of a sudden whilst driving.

I have an 06 A4 Avant 2.0T. Same engine as the A3, and I've had at least two coils replaced.

A tune up, consisting of new filters, plugs, oil etc made it drive a lot better, but prior to that, the dealer always denied any problem with acceleration until even they noticed and changed the coil (only one each time, which I found odd - and no mention of plugs).

Mine is from 2003 and replaced all 4!
They are relative cheap,

Grtz

Yeah I've seen them on Ebay for £15-£20 each. I tried to get one today from a scrappies just to get the car to the dealership but as it turns out when I rang them they said it had 12 months RAC coverage so I called them and they stuck a similar one on to get it there. Think I'll persuade him to get a couple spare just in case if they're a common thing.