E82 135i N55 - Misfiring :(

[Trakktion]

Hi,

Codes:

https://ibb.co/DkV07RH

So I’ve been getting misfires only when I floor it and go over 3k rpm. It goes in to limp mode with the half check engine light, and shakes like crazy. Car goes back to normal after a restart.

So far I’ve changed the spark plugs and coil packs, I’m thinking of doing the injectors next. On the diagnostics, it’s saying multiple misfires on multiple cylinders. Is it most likely to be the injectors?

I should probably mention I’m running MHD Stage 2+.

I really love driving this car but the constant issues are putting me off had my water pump and thermostat replaced last week...

Thanks for your help

[Petro135]

I hear you on the constant issues. My car is just one thing after another. But like my mechanic(who has several track cars in various states of disrepair) says "more power, more problems, more money".
I just went through constant misfires after I was finishing logs for my new turbos. Started with plugs and coils, went to cleaning injectors and putting new seals. Then back to thinking oil leak from vcg fouled a couple plugs(which it did). Then back to vcg and more plugs. Then to precision racing coils, then new injectors, then because I bent a injector hold down plate, had to fix that. Thats is after chasing 30ff boost leak codes all the way around the engine to turbos. And now fixing the several small oil leaks everywhere. But its a blast to drive.lol.
Seems everytime I put my foot to the floor it cost me $1000. I should have got a used boat. Lol!!
Anyway first thing you should try is cleaning, putting new seals, and switching around and recoding injectors and see what happens. After doing that my car went from misfires on 1 and 5 to nearly all cylinders misfiring. One of my injectors was loose from a crappy seal and would not take a new seal either, not sure why. I think it was worn down metal or something. There's cheap seal tool/injector kits out there. Invest in one if you don't already have one. Oh and look at your injectors while car is running first. Mine had one shaking in there.
Good luck

[Windy5000]

Hi & Welcome!

Having similar issues on a cold start, boost leak & pinched cam shaft after one - two hours of driving ECL replaced the below parts. Indy suspects it's a carbon build up problem and conducted a smoke test, a walnut blast and see how things go.

- x2 Solenoids
- Boost Pressure Valve
- Spark Plugs

[dtla1]

Nothing about fuel pressure too low? If so then I would say HPFP, but otherwise, maybe not.

[ferocity02]

Could be O2 sensor as well. Do you have a log?

N55's can also experience a "ghost" misfire caused by the flywheel but this usually doens't occur until you're pushing 450+ rwhp.

Is your car a DCT?

[SunnyState]

Originally Posted by Trakktion

Hi,

Codes:

https://ibb.co/DkV07RH

So I’ve been getting misfires only when I floor it and go over 3k rpm. It goes in to limp mode with the half check engine light, and shakes like crazy. Car goes back to normal after a restart.

So far I’ve changed the spark plugs and coil packs, I’m thinking of doing the injectors next. On the diagnostics, it’s saying multiple misfires on multiple cylinders. Is it most likely to be the injectors?

I should probably mention I’m running MHD Stage 2+.

I really love driving this car but the constant issues are putting me off had my water pump and thermostat replaced last week...

Thanks for your help

Hey, were you able to figure out the issue? Ive been having the exact same thing happen to me and im starting to go crazy!

[GoRomeo]

I keep hearing about these bad experiences with the N54 and N55 engines. I just bought one. Having an N52 engine with no major problems for 16 yrs and going strong. Now I am on this 1 forum trying to learn from you all. ..

Lets hope you find a solution for your issue soon

[bimmerchic]

Is buying a used engine going to fix this car or should I just give up? I replaced the missing parts but I can't replace the engine unless a miracle happens. So it sits in my garage and I'm torn whether to keep trying to make it a great car or give up. Any advice?