Smokin Coil

[xsara700]

Hi, I have just had a call from my mate who has recently bouht an A4 2.0 fsi sport '54' plate. The car has been fine then this morning he said it wouldn't start ,it just turnedover. he then checked the fuses after a call to mechanic. he changed no29. when he went to start the car it started but 1 of the coils started smoking and the top wasmelting. Has anyone heard if this is a common or known fault? he also asked if it will be ok to only change 1 coil pack? any help would be appreciated. Gav

 

[J7USS]

Never heard of that myself but answer to your last question is yes he can just change one if he wants.
I changed all 4 when one of mine went then kept the other 3 spare in my Boot, just incase!

 

[ScottyP45]

dodgy coil had blown the ignition feed fuse and killed it from starting, yeah replace that coil pack right away and watch for more failures on the rest of the original set.

 

[zeratul]

I had a coil go recently... S**t the hell out of me! Care was struggling to pull away, then the engine management light came on!

1st time I've drove away after calling the RAC - they just had to replace the coil.

But in regards to your last question... I was advised that one can be replaced but they tend to go in a certain order... ie if no.2 goes then no.4 will be the next or if no. 1 goes then no.3 is next and so on.

Anybody heard that before? I suppose thats why its advised to replace all four at once (if you can afford it).

 

[Steve B]

Good morning guy's
My car started driving like a bag of nails last night, showing the same signs as a dodgy coil pack. I pulled each of the leads of with the engine running, one of the leads was sparking all over the place. is this a sign that this one has gone, or is this the good one as the other three didn't really show to much sparking?
Is their another way to check which one is dodgy at home? I moved the sparking one to another leed, at it did the same,
Any advise would be great!
Cheers.

 

[ScottyP45]

pull off the low-tension plug to each coil pack itself, one by one, and the faulty one will make no difference to the rough running, a good one pulled off will make it worse.

A coilpack thats sparking all over the place has broken down insulation and wont work, especially in damp or wet weather.

Dont move the low tension connector to a different coil pack position i.e. cylinder, as you will ****** up the ignition firing order and it will either not run at all or run like a very nasty bag of ***** lol (this may not need saying but not clear on how you did the tests)

OR buy 1 new coilpack, about £25, and substitute each one in turn for the new one till it runs sweet. If its better but not perfect then you need more than one.

 

[Steve B]

Thanks for the reply,
Went and brought 1 coil pack and swapped it over with, what I thought was the dodgy one, same thing is happening, sparking seems much the same with a new coil as the old one, sparks and lots of clicking from new one much more than the other three. any idea?????????????????????? have Audi sold me a dud !!!!!!

 

[ScottyP45]

ah maybe the spark plug insulator is cracked! Or the recessed "well" itself is full of water (unlikely) -

(with the ignition OFF lol) pull out that coilpack from the "sparking" cylinder and using a plug-spanner or tube wrench, remove the spark plug itself and see if its broken? The white ceramic part must be undamaged, if its cracked or chipped at all, thats likely the problem.

You may just need a spark plug then, but the coilpack wont go wrong, you'll probably need it later on!

 

[Steve B]

HI sorry but not sure if I made myself clear,
The new one, I swapped this with all 4 of the cylinders, and the new one still sparks all over the place on each cylinder, much the same as the old, I have checked the plugs and they look fine, no damage showing. going to give the AA a call later to see if they have any ideas. thanks for all your comments and ideas, let me know if I could try anything else to confirm this ****** problem.

Steve.

 

[ScottyP45]

hmm, thats very weird, the primary side of modern ignition systems is high voltage compared to older ones, i.e. 400v primary and 30,000v secondary, whereas before it was 12v and 16000 to 20000v, 400v can arc but not over a large distance, it takes 40kv to jump an inch in dry air, maybe the fault lies in the low tension side but you might have a dud "new" coilpack from Audi after all!

If you can move one of the non-sparking originals around on other cylinders and it doesnt do it, then it must be the new one is faulty too.