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Discussion Starter #1
I was driving to a lunch engagement this past Saturday when, on the highway, I heard the infamous Bong of Disappointment, accompanied by two warnings: Engine Fault - Reduced Power, and Increased Emissions. Bugger.

On startup, the car runs normally at first, with only the Increased Emissions warning. Sometimes I can drive a short distance without reduced power occurring but, more often than not, the emissions warning is followed by the reduced power warning, accompanied by a rough idle and, of course, the redline being reduced to 5K RPM.

Active codes per my indy are:

1) 2B3D Misfire cutoff cyl 9
2) 2B4A Misfire impairing exhaust cyl 9

My SA (whom I have a good relationship with and is a down-to-earth guy, for the record) said that the symptoms and codes point to ignition coil problems, which aligns with my cursory search of the Board for threads about other owners facing similar situations. Here's the interesting twist - my indy suggested replacing ALL of the coils - AND plugs - to the tune of $2K. That is where the story diverges. Ignition coils fail at random, and without affecting the other system components, to include spark plugs, correct? Would there be any conceivable reason to replace ALL the coils and plugs - aside from a preventative maintenance tour-de-force? I DO intend to get a second opinion from another indy I trust. As ever, thank you in advance to all who reply.
 

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The codes you are getting are pretty much self explanatory...swap coil on cyl. 9 with coil on cyl. 8 and see if missfire code comes up at cylinder 8 as opposed to 9. If code persists on cyl. 9 then maybe it’s the sparkplug or fuel injector that is going bad.


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Need to diagnose before throwing parts at it. Could be spark plugs, coils, injectors, ionic module or worst case scenario broken spring valve. Replacing plugs and coils may not solve anything but empty your pockets.
 

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Discussion Starter #5
Need to diagnose before throwing parts at it. Could be spark plugs, coils, injectors, ionic module or worst case scenario broken spring valve. Replacing plugs and coils may not solve anything but empty your pockets.
I will have a more thorough diagnosis performed. Now that I think about it, I have to give the benefit of the doubt to my indy because he didn't have all the pieces to work with in terms of diagnosis - I just asked for them to pull the codes and not perform a full diagnosis because I was short on time today, and with the wealth of information on this board I knew I could quickly get in the ballpark with codes and symptoms alone. He didn't charge me, either. I will take it back to the original indy and then report back. Garbage in, garbage out, as they say. I do suspect that it will turn out to just be the cyl 9 coil.
 

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Discussion Starter #6
I have to say, buying my M5 has taught me more about the intricacies of modern automobiles and their associated technologies than I would otherwise have learned. PLCD's, ionic knock sensors - I wanted a pastime, but ended up in technical school! :p
 

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Discussion Starter #7
Quick update, it turned out to be the coil. Indy happened to have a new one in inventory, problem solved in two hours for <$200.00. Happy M, happy life! Now I just need to get that pesky passenger side sun blind sorted.
 

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It costed $200 to replace 1 coil?

damn, what a deal of a lifetime.

it pays to do or learn a few things yourself with cars like these.
 

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Discussion Starter #9
It's worse than that... I celebrated too soon. I went to a nearby coffee shop to get some work done on the ole laptop, and when I left, BONG! Reduced power again. I'm back at my indy again as I type this.

It's not that I can't turn a wrench, I can. I just have neither the time nor the desire to in the Houston summer funk. If you've ever visited Houston in the summer (or sat in a sauna, which is an interchangeable experience), you'll understand.
 

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It's worse than that... I celebrated too soon. I went to a nearby coffee shop to get some work done on the ole laptop, and when I left, BONG! Reduced power again. I'm back at my indy again as I type this.

It's not that I can't turn a wrench, I can. I just have neither the time nor the desire to in the Houston summer funk. If you've ever visited Houston in the summer (or sat in a sauna, which is an interchangeable experience), you'll understand.
Lol that last sentence was funny and completely true


2010 E60 M5 • Space Grey
 
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