View Full Version : E46 M54B30 330cic misfire - let's solve the problem

2011.11.03, 22:02 PM
OK, so the patient is my wife's E46 330cic ZSP steptronic.
It's got the 3.0L M54 double vanos engine.

This is a nice car with 75,000 easy miles that's recently started to misfire, more prevalent when cold, or when you stand on it.

Job #1, spark plug replacement. this was pretty straightforward.


net result, minimal improvement. slightly stronger start, misfires when dropped into R when cold.
next up: fuel filter.

2011.11.03, 22:03 PM

2011.11.03, 22:06 PM
It doesn't like the sunny weather. Dyslexic convertible.

2011.11.03, 22:08 PM
Coil packs or coil would be my guess. BMW's were just as reliable as the VW ones for that time. Although, E46's are shitting the stock fuel filter right about where you are at.


Also, have a wiki!

Rabbit 16v
2011.11.04, 08:53 AM
Have you identified which cylinder is misfiring?

2011.11.04, 09:23 AM
I have not. Unfortunately, there is no 'vag com' for BMW.
Fuel filter is next, if that doesnt solve it, I'll start investigating coil packs.
If I replace them it will not be with stock but with the upgraded packs from bavauto.


2011.11.04, 09:25 AM
I should buy one of these. Had one in frankendiesel... it was nice.

Rabbit 16v
2011.11.04, 10:06 AM
no need to use a scan tool to find the misfire. when it is misfiring, unplug one ignition coil at a time until the misfire doesnt change. That will narrow it down to which cylinder.

2011.11.04, 10:18 AM
its intermittent, yeah i get what you're saying and know how to do this kind of diagnosis, but I'm at the point in my research that echoes what twelver is saying... these things start to fail. I dont want to replace one and have them continue to start to die.

2011.11.04, 10:18 AM

2011.11.04, 14:37 PM

2011.11.04, 14:48 PM
oh hey that looks nice

2011.11.06, 17:48 PM
well, bavauto has their performance uprated coilpacks on sale, so I splurged. I also ordered fuel, air and cabin filters.
I'll do the fuel filter first to narrow things down... but after getting measurable seat time this weekend, I'm convinced it is a failing coil pack and I'll be damned if I'm gonna replace singles.

Rabbit 16v
2011.11.06, 18:15 PM
I havent checked into what you are mentioning, but I assume you mean there is an upgrade to a coilpack instead of COPs? Wouldnt this mean plug wires need to be added to the equation?

2011.11.07, 10:54 AM
no, it's an uprated COP setup. ive purchased from bavauto before I trust them.

Rabbit 16v
2011.11.07, 10:55 AM

2011.11.14, 22:07 PM
big box from bavauto on the porch today.
pity im sickas**** and refuse to work on the car.
tomorrow. maybe.

Rabbit 16v
2011.11.14, 22:31 PM
pussy :P Jk get well soon so we can see the results!

2011.11.16, 08:44 AM
swapped in the air filter, cabin filter and coilpacks yesterday. problem solved.

2011.11.16, 08:53 AM
I *knew* it was the damn cabin filter... :p

2011.11.16, 14:32 PM
heh yup damn modern cars :P

Rabbit 16v
2011.11.16, 20:02 PM
Props for the follow up! Oh, and they are ignition coils, not coilpacks :P

2011.11.17, 11:10 AM
pencil style coil-on-plug :P