2.0T Quattro S Line melted coil pack.

[692DPG]

I know there is much debate about the reliability of VAG coil packs but my latest problem causes me concern. 2 hours after last use with no symptoms, my A3 would't start, it cranked ok and fuel could be smelt but no ignition. On investigating, there was a strong electrical burning smell coming from the engine bay in the area of the fuse box and the main feed was drawing 20 amps with the ignition in the accessory position when measured using a current clamp. The cause is a short circuited, melted coil pack which having drawn in excess of 20 amps has blown the ECU 20 amp fuse. The car is in warranty and the dealer has changed all 4 coil packs and the burnt connector on the failed coil pack loom. The tech I spoke to has saved the coil pack for audi to investgate as he has not seen one fail that catastrophically before. I've only had the car 2 weeks and covered under 200 miles, given the potential degradation to the wiring system should I be concerned?

 

[Staz]

Not really. Fuses blow very quickly. The cabling is capable of carrying 20 amps and any on top would have blown the fuse before doing any damage to the loom.

 

[692DPG]

I agree in principle but in the failed condition, ie shorted out, it has put 20 amps through the coil transistor circuit and the earth lines albeit temporarily. I'm happy that the main ECU fuse has done its job but am more concerned with the potential damage to everything else on the L87 line in the wiring system like other electronic control modules. The buring smell from the fusebox was particularly strong. all I can get from the dealer is that they have fixed it, but they can't say for certain that there will be not and damage that will produce problems downstream. On this basis, I have the return option within the 30day/1000 mile guarantee so am trying to decide whether this would be better as I had intended to keep for 5 years plus.

 

[Staz]

Well not knowing the circuit I can't help you really. Sometimes there's no way of knowing if any damage has been done further up so the only thing you can do is ask them to check/replace it all or offer you a longer guarantee on the work carried out.

 

[Nickl]

I had my coils blow on me in my 2.0T at around 15k, had them replaced and haven't had any issues since, currently at 35k

 

[692DPG]

Thanks guys, getting the dealer to cover an additional warranty period would be a good idea. They replaced all 4 coils packs, the failed coil pack connector and the fuse box today but still can't verify whether any other consequential damage has occurred. Decision time tomorrow!