Misfire issue ! 7 cylinder

mcjoe691 · 02-22-2022, 09:13 PM

E92 M3 2008

I have E92 2008 M3 that says misfire cylinder 1-2-3-4-5-6-7-8 .

I have changed all coils and spark plug on all cylinders . With BMW ones .

Now it says Misfire on cylinder 7 .

Anyone had this problem ? I ordered a used fuel filter im waiting for . Anything else to check ?

Your help is greatly appreciated. Thanks it's my sons car .

fs34 · 02-22-2022, 09:49 PM

Have you done any other work recently? Did you change plugs and coils before or after this problem?

What scanning software do you have access to?

I’d start with checking voltages at the coils. I always mention this because I had a bad ground that caused misfires.

There are lots of possibilities here, post as much info as possible.

mcjoe691 · 02-22-2022, 09:52 PM

Quote:

Originally Posted by fs34

Have you done any other work recently? Did you change plugs and coils before or after this problem?

What scanning software do you have access to?

I'd start with checking voltages at the coils. I always mention this because I had a bad ground that caused misfires.

There are lots of possibilities here, post as much info as possible.

Quote:

Originally Posted by fs34

Have you done any other work recently? Did you change plugs and coils before or after this problem?

What scanning software do you have access to?

I'd start with checking voltages at the coils. I always mention this because I had a bad ground that caused misfires.

There are lots of possibilities here, post as much info as possible.

I changed all Coils and Spark plugs the code says misfire on cylinder 7 . I changed it before .

fs34 · 02-22-2022, 09:58 PM

Dumb question, did you double check all connections from coils to engine harness? Tried reseating coils? Swapping coils or plugs from 7 to somewhere else?

My misfire was 7, it was a bad ground but unless you did actuators or something in the valley, I don't think you'd have the same issue I had which was from someone who replaced TAs and didn't bolt the engine harness/grounds back down.

It was found with some voltage monitor in ISTA. No idea what your issue is, but I'd start with where I last touched the car and work back from there. If it's misfiring after you worked on it, best to start there.

mcjoe691 · 02-22-2022, 10:01 PM

Quote:

Originally Posted by fs34

Dumb question, did you double check all connections from coils to engine harness? Tried reseating coils? Swapping coils or plugs from 7 to somewhere else?

My misfire was 7, it was a bad ground but unless you did actuators or something in the valley, I don't think you'd have the same issue I had which was from someone who replaced TAs and didn't bolt the engine harness/grounds back down.

It was found with some voltage monitor in ISTA. No idea what your issue is, but I'd start with where I last touched the car and work back from there. If it's misfiring after you worked on it, best to start there.

Yeah I switched from cylinder 4 to cylinder 7 it says same thing .

spammysammich · 02-23-2022, 12:23 AM

Fuel injectors can go bad and cause bore scoring,low compression or hydrolock. Get a compression and leakdown test done.

mcjoe691 · 02-23-2022, 06:46 AM

Quote:

Originally Posted by spammysammich

Fuel injectors can go bad and cause bore scoring,low compression or hydrolock. Get a compression and leakdown test done.

I will check that out today .

Three Pedal Steve · 02-23-2022, 01:36 PM

Broken valve springs are a known problem on S65 engine.

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Battle · 02-23-2022, 02:22 PM

Quote:

Originally Posted by Three Pedal Steve

Broken valve springs are a known problem on S65 engine.

Attachment 2819884

How do you keep from misfire besides annual spark plug change?

spammysammich · 02-23-2022, 02:25 PM

Quote:

Originally Posted by Three Pedal Steve

Broken valve springs are a known problem on S65 engine.

Attachment 2819884

That is nightmare fuel.

fs34 · 02-23-2022, 03:14 PM

Quote:

Originally Posted by spammysammich

That is nightmare fuel.

When I had my issue this is what the original diagnosis was. I had tried everything swapping coils, injectors, plugs. Gave up and had it towed to BMW. After 6 plus hours of diagnosis they found nothing. The tech then said he was putting it back together to start over and re check. That’s when he found a missing nut on the engine harness, which led to a bad ground.

Went through the emotional roller coaster of thinking I needed a $7500 valve job to a $1 nut. Glad that is over but I learned a lot. Hope it’s something simple like this for the OP.

mcjoe691 · 02-25-2022, 12:22 PM

Quote:

Originally Posted by fs34

Quote:

Originally Posted by spammysammich

That is nightmare fuel.

When I had my issue this is what the original diagnosis was. I had tried everything swapping coils, injectors, plugs. Gave up and had it towed to BMW. After 6 plus hours of diagnosis they found nothing. The tech then said he was putting it back together to start over and re check. That’s when he found a missing nut on the engine harness, which led to a bad ground.

Went through the emotional roller coaster of thinking I needed a $7500 valve job to a $1 nut. Glad that is over but I learned a lot. Hope it’s something simple like this for the OP.

I hope

alfalfa · 02-25-2022, 12:36 PM

Quote:

Originally Posted by Three Pedal Steve

Broken valve springs are a known problem on S65 engine.

Attachment 2819884

Mileage when this happend?

DrFerry · 02-26-2022, 08:47 AM

Quote:

Originally Posted by Three Pedal Steve

Broken valve springs are a known problem on S65 engine.

Attachment 2819884

Ouch..

02-22-2022, 09:13 PM	#1
mcjoe691 Lieutenant 306 Rep 528 Posts Drives: 2015 M3 Join Date: Sep 2011 Location: Viera , Florida iTrader: (0)	E92 M3 2008 I have E92 2008 M3 that says misfire cylinder 1-2-3-4-5-6-7-8 . I have changed all coils and spark plug on all cylinders . With BMW ones . Now it says Misfire on cylinder 7 . Anyone had this problem ? I ordered a used fuel filter im waiting for . Anything else to check ? Your help is greatly appreciated. Thanks it's my sons car . __________________ Build by (PSI) 2019 M2C , BC suspension , BC wheels , DP , Vorsteiner trunk lip , Diffuser , Side Skirts , IND reflector kit , Rw carbón hood , DME Tuned ! E90 M3 Supercharged
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02-22-2022, 09:49 PM	#2
fs34 Lieutenant 412 Rep 428 Posts Drives: E46 M3 Join Date: May 2019 Location: Huntsville, AL iTrader: (1)	Have you done any other work recently? Did you change plugs and coils before or after this problem? What scanning software do you have access to? I’d start with checking voltages at the coils. I always mention this because I had a bad ground that caused misfires. There are lots of possibilities here, post as much info as possible.
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02-22-2022, 09:58 PM	#4
fs34 Lieutenant 412 Rep 428 Posts Drives: E46 M3 Join Date: May 2019 Location: Huntsville, AL iTrader: (1)	Dumb question, did you double check all connections from coils to engine harness? Tried reseating coils? Swapping coils or plugs from 7 to somewhere else? My misfire was 7, it was a bad ground but unless you did actuators or something in the valley, I don't think you'd have the same issue I had which was from someone who replaced TAs and didn't bolt the engine harness/grounds back down. It was found with some voltage monitor in ISTA. No idea what your issue is, but I'd start with where I last touched the car and work back from there. If it's misfiring after you worked on it, best to start there.
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02-23-2022, 12:23 AM	#6
spammysammich Major 1606 Rep 1,128 Posts Drives: 2009 E92 M3 Dakar Yellow II Join Date: Oct 2021 Location: Edmonds, WA iTrader: (0) Garage List 2009 BMW M3 [10.00]	Fuel injectors can go bad and cause bore scoring,low compression or hydrolock. Get a compression and leakdown test done.
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02-23-2022, 01:36 PM	#8
Three Pedal Steve Captain 877 Rep 611 Posts Drives: 2013 M3 coupe' 6mt Join Date: Apr 2013 Location: Under a Waterfall in Highlands NC iTrader: (0) Garage List 2013 BMW M3 Coupe [0.00]	Broken valve springs are a known problem on S65 engine. __________________ memories: '71 2002 (new), '72 Bavaria, '74 2002tii, '00 540i Sport
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