Misfire

Lozza47 · 10-27-2021, 04:57 AM

Hi all,
I recently purchased a 2011 M3 and have had issues with cylinder 6 & 7 not firing. Car is constantly in limp mode, engine running very rough as if 6 & 7 not combusting at all. No power.
The codes are:
002758 - ignition cylinder 6 controlling electrical diagnostic
002759 - ignition cylinder 7 controlling electrical diagnostic

I have tried the following:
- Swapped coils around on 6 & 7 to other firing cylinders
- Brand new plugs on 6 & 7
- Checked voltage and coil plug connector
- Checked injectors seated properly
- Reset codes, adaptations and battery disconnected

No luck so far.
Before I picked up the car from the dealer, they did a valve cover gasket change.
The dealer isn’t coming to the party just yet to look at the car so taking it into my own hands.
Another thing, I can hear a whistle from the plenum, same side as the cylinders throwing codes. Would a plenum leak lead to codes like this?
Any help would be much appreciated.

amrazM · 10-27-2021, 05:08 AM

check the ground on the valve cover of the bank that is misfiring. I assure you its loose

tdott · 10-27-2021, 07:01 AM

When you say you swapped coils, did you swap them with cylinders that are not mis-firing? Just wanted to be clear, sounded like you just swapped 6&7 around which wont help.

Lozza47 · 10-27-2021, 04:15 PM

Quote:

Originally Posted by amrazM

check the ground on the valve cover of the bank that is misfiring. I assure you its loose

I'll check that, thank you.

Just to clarify, is it this ground?

https://ibb.co/jzQvKtH

Lozza47 · 10-27-2021, 04:17 PM

Quote:

Originally Posted by tdott

When you say you swapped coils, did you swap them with cylinders that are not mis-firing? Just wanted to be clear, sounded like you just swapped 6&7 around which wont help.

Yes, sorry that was unclear. I swapped them with cylinder 1 & 5 which were firing okay.

linnadawg · 10-27-2021, 04:39 PM

I just solved mine. It was only cylinder 3 for a while. This morning I had all kinds of misfire codes and the entire passenger banks fuel injectors were turned off. I scoped the passenger side ignition coil control wires and they all had random voltage spikes, which usually indicates a bad ground. Removed the ignition coil cover and the ground at the rear of the valve cover was loose. If you look at a wiring diagram it’s the ground for the suppression capacitor with all of the orange wires. Even though it’s a ground for all 4 coils it gave me a cyl 3 activation code for the longest time.

Lozza47 · 10-28-2021, 02:33 AM

That ground cable was loose indeed. All fixed thanks for the tip guys.

10-27-2021, 04:57 AM	#1
Lozza47 Private First Class 38 Rep 129 Posts Drives: 2013 F30 335i / 2011 E92 M3 Join Date: Sep 2019 Location: Melbourne iTrader: (0)	Misfire - ignition cylinder 6/7 limp mode Hi all, I recently purchased a 2011 M3 and have had issues with cylinder 6 & 7 not firing. Car is constantly in limp mode, engine running very rough as if 6 & 7 not combusting at all. No power. The codes are: 002758 - ignition cylinder 6 controlling electrical diagnostic 002759 - ignition cylinder 7 controlling electrical diagnostic I have tried the following: - Swapped coils around on 6 & 7 to other firing cylinders - Brand new plugs on 6 & 7 - Checked voltage and coil plug connector - Checked injectors seated properly - Reset codes, adaptations and battery disconnected No luck so far. Before I picked up the car from the dealer, they did a valve cover gasket change. The dealer isn’t coming to the party just yet to look at the car so taking it into my own hands. Another thing, I can hear a whistle from the plenum, same side as the cylinders throwing codes. Would a plenum leak lead to codes like this? Any help would be much appreciated. Last edited by Lozza47; 10-27-2021 at 08:01 PM.. Reason: Spelling error / unclear
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10-27-2021, 05:08 AM	#2
amrazM mTekMods 2157 Rep 2,909 Posts Drives: like a granny. Join Date: Jan 2010 Location: Manhatan iTrader: (1)	check the ground on the valve cover of the bank that is misfiring. I assure you its loose __________________ 2011 Frozen Black/Fox Red E90 M3 650+WHP G-Power Supercharged First DCT to Manual Conversion Worldwide KW CS, BBS RI-A, BW Headers, Snow 2.5
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10-27-2021, 07:01 AM	#3
tdott Brigadier General 3956 Rep 3,994 Posts Drives: M3 Join Date: Nov 2010 Location: South FL / 6ix iTrader: (4)	When you say you swapped coils, did you swap them with cylinders that are not mis-firing? Just wanted to be clear, sounded like you just swapped 6&7 around which wont help. __________________ N/A S65 Headers Before/After Dyno Results
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10-27-2021, 04:39 PM	#6
linnadawg New Member 6 Rep 29 Posts Drives: 06 330i Join Date: Dec 2014 Location: Ca iTrader: (0)	I just solved mine. It was only cylinder 3 for a while. This morning I had all kinds of misfire codes and the entire passenger banks fuel injectors were turned off. I scoped the passenger side ignition coil control wires and they all had random voltage spikes, which usually indicates a bad ground. Removed the ignition coil cover and the ground at the rear of the valve cover was loose. If you look at a wiring diagram it’s the ground for the suppression capacitor with all of the orange wires. Even though it’s a ground for all 4 coils it gave me a cyl 3 activation code for the longest time.
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10-28-2021, 02:33 AM	#7
Lozza47 Private First Class 38 Rep 129 Posts Drives: 2013 F30 335i / 2011 E92 M3 Join Date: Sep 2019 Location: Melbourne iTrader: (0)	That ground cable was loose indeed. All fixed thanks for the tip guys.
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