M3 E92 2011 - Fault Help - P0304 P0354 - Misfire

[gaz_0001]

Hi All,

I wonder if somone can help me with the two fault codes and provide some guidance so thst the local shop doesn't have me over.

My 2011 M3 E92 DCT went into limp mode this morning with Cylinder misfire alarms.

Theres a little bit of a story because this is the 2nd time this fault has surfaced on the car.

May 2023

Took car for oil service.
I had a small leak on valve cover which had been there for a year or so.
Got them to replace the gaskets and fix the leak on the valve cover.
Had the Spark Plugs replace with OEM since they were almost due.

Nex day, P0304 Cylinder 4 Misfire Detected appeared. First time ever.

The garage wanted to charge me all sorts for coils and such.
Since the plugs were replaced the day before , I suspected they had been put in wrong or faulty.

The garage swapped Plug from #4 to #2, and coil from #4 to #3.

The car has been running great since, and I put the alarm down to shit installation of the plugs.

In the past 9 months since them, I've done around 6000km in this car.

Feb 2024

Went into limp mode randomly.
Alarms are:

P0304 Cylinder 4 Misfire Detected
P0354 Ignition Coil D Primary/Secondary Circuit

Appreciate your ideas and experience before I head back to the garage.

Thank you

[Theodore]

I would carefully check the wiring to the coil pack on #4, the plastic connector plug on #4, and the coil pack wiring grounds on the valve covers.

Check out this thread here which had these two solutions posted:

Originally Posted by Bruuuce

I had a broken valve spring that caused intermittant issues. Hard to believe. The leak down test finally proved the issue

Originally Posted by Jacooobs`n

Problem solved!
After spending too much money on local BMW, I listed the issue on a facebook page for //M-car owners in norway and got a tip from a aftermarked mechanic that told me to replace both coil and plug at the same time as a broken plug damages the coil and the other way around.
So, changed both plug and coil and problem solved!
If I had posted my problem there earlier, it could save me a lot of money..

I have never seen this as a solution for any misfiring anywhere on the internet so hope this could help many of you with similar problems around.
I told local BMW workshop and they really didn`t know

[gaz_0001]

Originally Posted by Theodore

I would carefully check the wiring to the coil pack on #4, the plastic connector plug on #4, and the coil pack wiring grounds on the valve covers.

Check out this thread here which had these two solutions posted:

Thanks you buddy.

I was thinking that because I already swapped over them in May 2023 as part of troubleshooting, that it could (or should) not be the coil or plugs.
I will be passing by a different garage than usual anyway, so I'm sure they will start here with the most common checks.

I just arrived back home, started it up and all cylinders firing.
I didn't have chance to drive it yet, I'm sure the fault will return once I get it on the road.

Thanks again

[fs34]

Remove the plug from cylinder 4 and inspect it. Could have a spark plug tube that isn’t seated properly allowing oil in there.

They are supposed to be replaced with a VCG job, could be a bad install of that one, or not replaced at all.

As mentioned before, valve spring could be an issue, I hope for your sake it is not the problem.

I had a similar issue with mine, misfire that wouldn’t follow coil, plug, or injector swapping. Have you/they tried swapping injectors to see if it follows the swap?

My issue was ultimately one of the engine harness grounding nuts causing a bad ground and misfire on 7. You can monitor voltages with ISTA.

Best of luck finding your issue.