GTI Misfire and diagnosis

[simmo675]

Hi - This is my first 'techie' post so bear with me! I thought I would post this up to help anyone else who may find themselves in this situation..........

I have an AGU engine'd GTI which has recently developed a misfire - rough running, loss of power and a lovely eggy smell from the CAT. So I got straight online to try and research what the problem might be. I've read up on the igntion coil issues that later model 1.8T cars were having, particularly in the US, but it turns out that there were no AGU engine GTI's exported to the States, as far as I can tell.

It turns out that the AGU engine uses a different, older style of ignition coil that is complemented with an Ignition Control Module (ICM); basically a four way switch that powers up the primary coil in each of the individual 'plug caps'. The coils or plug caps are supposed to be fairly durable, and the ICM is the weak link in the chain. When VW changed the design the weak link moved from the ICM (which was removed) to the individual coils on each plug.

However, being a tightwad, I don't like replacing things without checking them first! I invested in a VAG -COM cable when I bought the car, so did the checks to find the misfire - No. 2 cylinder. But - VAG-COM doesn't show up any fault code for the ignition control module......then I stumbled across this gem: http://forums.audiworld.com/a4/msgs/1594531.phtml

I know this is for the Audi A4, but the ICM part numbers are identical. I followed this procedure and what do you know - no continuity on no. 2 cylinder. Bingo!

So that was the easy part - finding a reasonably priced replacement was a bit more tricky! Oops, nearly forgot - the part number is 4D0 905 351

Eventually I found this: http://www.aboveallmotorwerks.com/Pr...0905351_S.aspx

With shipping (not free to Aus - what a surprise!) it came to $149.97 USD, which at the moment is about $225 AUD.

As a comparison HSY gave me a price of $236AUD + GST, and the stealer price is nearer $400 (ouch)

I ordered the part yesterday - USPS priority shipping should get it here in a week I guess. Bit of a pain because I can't use the car, but I have alternative two wheeled transport which is handy.

Now all I need to do is fix the rear door that someone hit and run last weekend............

[qsilverza]

The Eggy smell could also be caused by an 02 sensor. But sounds like you are on the ball !

[No457 Snowy]

Nice bit of troubleshooting mate! I'm not shocked at the local dealer price though, once again it's a bloody rip-off.

Just on the subject of buying parts, see my comments here


Snowy

[sierra055]

I think they also refer to that part as the final output stage, is that right?
I had mine die on me too, but was replaced locally by the mechanic at around $250 if i recall correctly.

[simmo675]

Hi Sierra055

yes, there appears to be several different names for it - which is technically correct tho?! The guy who wrote the Audi based article seemed to know his stuff and referred to it as the Output Stage Module; I think I'll call it an N122 module from now on - my mind works better with small numbers!

Hey Snowy

That is a tricky one - as a new arrival to these shores I can only guess why local prices are higher, I suppose that at the end of the day prices are driven by what people are prepared to pay.......