I have tried a search and found some usefull info out but I wanted to ask a specific question, Is it likely for all 4 coilpacks to go within 2 days?

It all started 3 or 4 days ago when the car (vrs) started idling strangely while stopped at the lights, just a kind of random shudder and drop of rev, Moving off no problem plenty power, no hesitation. just this lumpy idling. so i've been out with vag com when i got home and it reterned no codes, pulled out the first couple of coilpacks to take a look then put em back in and wham bad misfiring engine sounding like a tractor, back on with the vagcom and appart from the fact that misfire detection always seems to be disabled eventually got it on and it starts counting up misfires on cylinder 1 and 2, so i swap 1 to 4 then test again i'm getting misfires on 2 and 4 now so i think OK 2 new coilpacks. ( i swap 1 and 4 back again since 4 isnt as accesable) I get my to new coil packs and put em in 1 and 2. Start the engine up, much better but back to the original shudder in the idle and over the next few minutes reverts back to quite regular misfires. Put VagCom back on and fiddle till misfire detecting starts working, now its saying 3 and 4 are misfiring!

Can the new ones affect the old ones?

is there some thing i am missing?

I'm gonna clean the throttle body and reset it with vagcom when my new gasket arrives.

Any ideas, to save a trip to the dealers would help. Thnks folks.

I dont know if something else could be causing it but i had 2 go at once on an a3 and a couple of days later a third changed them all and no more problems.

Have you checked your spark plugs??

Coilpacks are the place to start.

They can start breaking down before completely failing, and becoming detectable to VAG-COM.

Happened to me a few weeks back.

One of them had burnt in half

hi guys thanks for the replies, sounds obvious but no i didn't check sparkys yet (my sparkplug socket isn't very good) i'm just going out to check them out just now, they've got 35000 miles on them and would be due at 80000m service anyway which is only 5000 away, I was pretty stressed yesterday thinking of all the worst things it could be, but seeing as vagcom isn't throwing up any problems from the maf or lamda sensors etc i guess it willl just be coils or plugs, Another thing a mate suggested was maybe a semi clogged fuel filter or failling fuel pump. I need to do the fuel filter anyway so that is on my list.

what can vagcom detect?

would vacuum leaks or lack of compression show up or do i need to physically test these things? (assuming plugs and coils dont fix it)

Ok checked plugs, they all look the same, kinda dry fouled (see pic) could that amount of carbon build up happen durring the accumulated 15 mins or so of fault finding with assorted coil problems? or do you think they look about right for 35000 miles? all are gapped at 0.7mm perhaps theres a tenth of a mil carbon deposited on them.

Edited 2 November, 201015 yr by pixelmassacre

hi guys thanks for the replies, sounds obvious but no i didn't check sparkys yet (my sparkplug socket isn't very good) i'm just going out to check them out just now, they've got 35000 miles on them and would be due at 80000m service anyway which is only 5000 away, I was pretty stressed yesterday thinking of all the worst things it could be, but seeing as vagcom isn't throwing up any problems from the maf or lamda sensors etc i guess it willl just be coils or plugs, Another thing a mate suggested was maybe a semi clogged fuel filter or failling fuel pump. I need to do the fuel filter anyway so that is on my list.

what can vagcom detect?

would vacuum leaks or lack of compression show up or do i need to physically test these things? (assuming plugs and coils dont fix it)

Ok checked plugs, they all look the same, kinda dry fouled (see pic) could that amount of carbon build up happen durring the accumulated 15 mins or so of fault finding with assorted coil problems? or do you think they look about right for 35000 miles? all are gapped at 0.7mm perhaps theres a tenth of a mil carbon deposited on them.

looks to be running a bit rich there mate, bit too sooty!

Out of interest did you replace them with OE coils or cheapos?

I had a cylinder 3 misfire around a month or two ago and once the car failed to start, I bought a new coil pack and it worked bang on.

However this monday I checked it with the scanner again and this time it was cylinder 2 and 4 misfiring, along with the random misfire code so I bought 3 new coilpacks. Since then no more misfires and the car is running smoother.

Ok i got new plugs in today, just before the rain came down, but unfortunately no difference. I started off with the new plugs in but back on all 4 old coils, then started the engine to hear it still running like a dog . So i start unplugging coils in turn to see which one has no effect (so is the shagged one).

first pass along: coil 2 does not cause a drop in revs when unplugged, all others do. Put a new one in number 2. then restart procedure.

second pass along:coil 3 does not cause a drop in revs when unplugged, all other do. so now 3 not working when it did one moment ago!

I get the feeling i could be playing musical coilpacks all day (i only bought 2 new ones) and the rain is getting worse. ****ed off that the faulty one is moving around, that coupled with my fouled plugs make me think something else may be at fault.

Rain really pishing now so given up, I can hear a concerning air rushing noise with the bonnet up so i'm just gonna leave the damn coils for now and try to test for vacuum leaks. Any one got a good pic/ diagram of where all vacuum hoses run?

Edited 5 November, 201015 yr by pixelmassacre

Ok coils and spark plugs had me barking up the wrong tree. Just shows that a muppet armed with only a smattering of car mechanical knowledge and vagcom aint the most efficient way to find a problem! Vac leak it was, split pipe found. see pic.

dont know how much thes cost yet but i think the awsome gti silicone ones (http://www.awesome-gti.co.uk/product.php?xProd=13304) are a bit over the top at £70 although i reckon to buy both oem ones will be a fair bit too tho, I obviously only need the one just now.

I bought the same pipe as that from Trade Part Specialists a couple of years ago, & pretty sure it was under £20.

I bought the same pipe as that from Trade Part Specialists a couple of years ago, & pretty sure it was under £20.

yep think i saw it priced at £11ish plus VAT. it'll be TPS I use probably or maybe Chathams in Edinburgh.

Did you have no codes ???

When my hose went it popped the 17705 code

Did you have no codes ???

When my hose went it popped the 17705 code

No, i had no codes, and the engine management light didnt even come on, not really sure why, even block 32 (idle fuel trims) was reading within tollerance on VagCom although i'm sure the split has been getting bigger since the last time I scanned, which also explains why i didn't hear it at first.

P.S in case anyone stumbles on this in future forum searches, that pipe is 06A 103 221 AF which has been superceded by 06A 103 221 BK.