Misfiring, juddering, flashing engine management light....help!,

Hi all, spent my day today fitting a catch can due to having a boost leak and thinking it wouldnt hurt to install it. Got it all done took it for a spin and all was good, car was boosting fine and driving better than it was previously. On my way home i put it in fourth and boosted it hard and it started to judder and the engine management light started flashing. Nursed it home gently and it seems like its misfiring and the idle is very rough. The engine management light is now on constantly but did briefly flash.

I have had the plugs out to checkand they seem fine. I ran it at idle and unplugged each coilpack in turn to try and determine if its a coilpack but it was hard to determine if it made a difference. I also tried unplugging the MAF at idle but this seemed to make very little difference either.

I know i should get it put on vagcom but dont have access to it yet. If anyone could point me in the right direction then id very much appreciate it.

Car is a mk4 golf 1.8t btw. Forgot to add that at the top lol

 

sounds like a common coil pack issue

how old are the plugs?

without vagcom itll be hard to diagnose the coilpack as i have seen them fire at idle but miss when on load

 

100% coilpacks mate. Had them go in the past with all your symtoms.

Or it could be an injector plug has popped out.

 

Plugs are only a matter of weeks old so ive kinda ruled that out, could still be the prob tho i know.

Im almost convinced its the coilpacks or one of anyway as these are a common prob on the aum.

Which coilpacks are the best to use on an aum?? I read about people using agu coils as a replacement and also people using tfsi coils from a mk5 for reliability.

 

i gave a mate a set of my old arz coilpacks to use on his aum. they bolt down and i still had original ones at 170K

 

I replaced mine with Beru OEM quality ones.

Been fine ever since. Stay away from budget eurocarpart ones as they only last a month or so.

 

I will definately only buy genuine and i will be replacing all 4 as well. Was wondering if its worth me changing fir arz engine code coils as these bolt down and are apparently 4 pin so fit the agu??

 

AGU has 3 pin coilpacks.

AUM has 4 pin ones.

Not sure on the ARZ though ?

If you buy genuine AUM ones, they will last. Mine were original, and decided to blow at 65,000 miles. Not bad eh.

 

arz are bolt down and same pin config as aum, same ecu etc

i got hitachi and beru replacements from eurocarparts, but still had two original hitachi ones after 170k!

 

Looks like i need to track down some arz coilpacks if thats the prob. Anyone know prices??

 

Had it on vagcom earlier and it came up with a misfire to cylinders 1 and 4, cant remember the exact code but does that mean that ive got 2 coilpacks gone?? Anything that would cause 2 to go at the same time??

 

When my original ones failed on my AUM Mk4, 1 went first and the other 3 followed near enough straight away.

If yours are original i'd replace all 4 tbh.

Got my Beru ones from GSF as they are half the price of VW ones, and are the OEM equivalent

 

I was going to replace all 4 anyway. Dont want the hassle.

Im going to replace them with arz bolt down coilpacks. Vw quoted 31.73 + vat each which i thaught was reasonable.

 

Thats not bad tbh.

Remeber you'll need 8 x bolts to bolt them down with too!

 

Yeh i know about the bolts. Assume i need the seals too??

 

Got a set of brand new arz bolt down coilpacks , fitted them and it now runs like a dream. Thanks guys

 

Which make?

 

Genuine from vw mate. How come???

 

there are a few different makes, wondered what make you got

 

Is there a difference then?? Tbh i didnt know there was different makes. Just went to vw and got arz coil packs. Where will it say what make they are??