[stuartbrown.e90]

So over the past few months my car has been having weird misfire problems. Whenever it acts up MHD reads multiple or all cylinder misfires. Around 8k miles ago I replaced all the spark plugs as well as 2 of the coil packs. We took them all out about 1k miles ago to look at the plugs and clean them to see if there was anything blatantly wrong, and they were all extremely dirty and gunked up. One of the coil packs as well had a bit of grime on the outside, which shouldn’t usually happen. The car also smells of fuel whenever you first start it up which makes me think it is running rich as well. I doubt it would be the injectors because it is strange for them to all go out at once.
My car also does this strange thing where when you are driving and barely rest your foot on the throttle the gas, not enough to actually accelerate, it will burble very slightly as if fuel is getting leaked into the exhaust system.
Yesterday, I found out that if it is misfiring and you clear the codes through MHD, it will stop misfiring and run as if nothing had happened which I found very strange. Almost as if there was nothing mechanically wrong and it just had to have the app tell it to work right again.
All of it is just a very weird (at least to me) combination and I wanted to put this out there for some of the more experienced n54 guys to throw out some ideas or maybe yall have experienced something similar??

I’ll include some screenshots of the MHD dme codes as well as a photo of how fouled up the spark plugs were after only 7k miles or so.

[lookalikehuuh]

Man you have some serious issues going on here. Those spark plugs look awful to say the least. When is the last time you replaced the coil packs as well since you apparently have some mismatched ones there too.

We really need a log of your car running/accelerating so we can see what your engine parameters are, I also suspect you are running super rich and/or you are burning excessive amounts of oil based on the condition of the spark plugs that you posted in the picture. When is the last time you changed out the PCV on your car? Its highly likely that your injectors are leaking.. are they original? do you know what index they are?

[ptpending]

also the question is if injectors were replaced to latest revision or no
what is service history

[stuartbrown.e90]

I have only owned the car around a year and have not replaced the PCV or injectors. As far as I am aware the injectors are still the originals (car has 106k miles). I am still fairly new to the mechanical side of cars as this is the first car I have really worked on myself. I looked back through the maintenance records and other than regular services it looks like the injectors haven’t been touched and neither has the pcv.

[stuartbrown.e90]

The 2 mismatched coil packs were replaced when I first got the car a year ago and had my local shop do a quick service. Not sure what their reason was for only replacing 2 coil packs. They replaced all the plugs though

[ptpending]

you need to replace all coil packs, coils
and check the injector part number at least,
if they are less then 09 revision you need to source used or new 12 revision injectors as a minimum
bmw replaced them as a warranty, but this action is ended

[stuartbrown.e90]

That’s what I’ve been thinking about doing. I’m going to buy 2 step colder plugs and just go ahead and switch out all the coils. I looked more into the pcv valves as well an im pretty sure mine has never been replaced. Since it’s only by $50 I might as well go ahead and swap it out just because. I’ll also check the injector index while i’m in there and just hope and pray that they’re index 12s. Also since my injectors as probably at least a little bit clogged I was wondering if injector cleaner such as sea foam or some other additive would be of any help to them.

[stuartbrown.e90]

Even without the misfires I probably need to replace all those things anyway because I’m planning on being FBO in the next 2 weeks when I get around to installing the cat less downpipes (already have in a charge pipe, intakes, and intercooler). Also how beneficial would a walnut blasting be for the intake valves? I doubt that’s ever been done either…

[lookalikehuuh]

Originally Posted by stuartbrown.e90

That’s what I’ve been thinking about doing. I’m going to buy 2 step colder plugs and just go ahead and switch out all the coils. I looked more into the pcv valves as well an im pretty sure mine has never been replaced. Since it’s only by $50 I might as well go ahead and swap it out just because. I’ll also check the injector index while i’m in there and just hope and pray that they’re index 12s. Also since my injectors as probably at least a little bit clogged I was wondering if injector cleaner such as sea foam or some other additive would be of any help to them.

Hold on hold on... why do you need 2 step colder spark plugs? You don't have upgraded Turbo's right?

If you are running stock turbos you should keep the OE Bosch spark plugs as they will perform better with less issues that the NGK 1 step or 2 step colder plugs. From what I have seen the colder plugs are for dudes with hybrid or single turbo running big power not for dudes with stockers.

For the record I run "Stage 2+ E60" tune so kind of pushing the limits of the stock turbos and my car runs way better on the Bosch OE plugs than the NGK 2 step colder plugs I ordered initially. My car would develop a random misfire on WOT pulls in 3rd or 4th gear that I chased for a long time. Eventually someone suggested i move back to the OE Bosch plugs and that solved the issue entirely for me.

Also if you are going to be tuning I would recommend going with the Eldor coil packs since they seem a bit more robust than the Bosch OE ones.

As far as I understand it the preference on coil pack brand are as follows:
Bosch<Delphi<Eldor

[whyzee125]

It looks like you very likely have some leaking injectors. If they're all original it would not surprise me at all if they're all leaking, though you don't have misfire codes on every cylinder.

Put 6 fresh plugs in it, start it for a bit, and check the plugs in the morning. If any are wet or smell like fuel, you have a leaking injector on that cylinder.

A log would also be helpful though with how bad your plugs look, I wouldn't recommend pushing the car at all until you get this sorted out.

Also there's absolutely zero need for colder plugs. The OEM Bosch are the best plugs for your setup.

[stuartbrown.e90]

Ah I see. I had just heard that when you start pushing more power it helps to have the 2 step colder plugs. But I guess i’ll just stick to the bosch ones for now. Also for doing the log do you need the monitor liscense in MHD? I have the flash and tuning liscense as of right now but not the monitor.

[lookalikehuuh]

Originally Posted by stuartbrown.e90

Ah I see. I had just heard that when you start pushing more power it helps to have the 2 step colder plugs. But I guess i’ll just stick to the bosch ones for now. Also for doing the log do you need the monitor liscense in MHD? I have the flash and tuning liscense as of right now but not the monitor.

Yes, in fact I would actually argue that the monitor license should be the first one to buy (for those not buying the super license). Its really important to log first before you run any tune to ensure your engine is healthy enough to even be tuned.

[suspect]

You have high pressure fuel codes too. Multiple cylinders and these codes could mean HPFP.

[stuartbrown.e90]

Ok so I bought the monitor liscense and ran a quick log. The first one is doing a little pull just to show the boost psi and what the engine is doing. There are really no misfires during actual driving only when the car has been running and then is left to idle. It’s very strange. The second log is after a 20-25 min drive when it is set to just idling. There is some timing correction stuff going on (weird spiking orange line at the bottom). Anyone experienced that knows how to read further into MHD logs to figure out what might cause that? Or does anything look strange and out of ordinary. I wouldn’t really know because this is my first time looking at the graphs/numbers.

[lookalikehuuh]

Originally Posted by stuartbrown.e90

Ok so I bought the monitor liscense and ran a quick log. The first one is doing a little pull just to show the boost psi and what the engine is doing. There are really no misfires during actual driving only when the car has been running and then is left to idle. It’s very strange. The second log is after a 20-25 min drive when it is set to just idling. There is some timing correction stuff going on (weird spiking orange line at the bottom). Anyone experienced that knows how to read further into MHD logs to figure out what might cause that? Or does anything look strange and out of ordinary. I wouldn’t really know because this is my first time looking at the graphs/numbers.

Take this log and create and account on https://datazap.me/. Upload that log you just took so we can all edit/review the log to our heart's content and we can give you way more information that the small snapshot you posted here.

Once you have it uploaded, send us the link to the log and we can give you way more information on what is going on.

[stuartbrown.e90]

Just uploaded them to datazap so yall can see them.
here is the link to the pull Pull log
this is the link to the idle misfires idle link

[Sgop335]

Lambda banks are slow to respond, esp bank 1...injectors could be leaky...plugs color 1236 are rich

[lookalikehuuh]

I also realized you are on v9, those weren't great for me...

Anyway I agree that your bank 1 AFR are super slow to respond. it also seems like fuel trims start up pretty negative and slowly improve... also suggesting you have leaky injectors. Some have reported an improvement by filling up with some good fuels (shell/chevron) and adding bottle of techron to the tank. Maybe worth a try since the injectors for these cars are crazy expensive.

Do you happen to know what index injectors your car currently has?

[stuartbrown.e90]

Originally Posted by lookalikehuuh

I also realized you are on v9, those weren't great for me...

Anyway I agree that your bank 1 AFR are super slow to respond. it also seems like fuel trims start up pretty negative and slowly improve... also suggesting you have leaky injectors. Some have reported an improvement by filling up with some good fuels (shell/chevron) and adding bottle of techron to the tank. Maybe worth a try since the injectors for these cars are crazy expensive.

Do you happen to know what index injectors your car currently has?

I am going to check this morning what index they are but right now I am not sure. It definitely could be leaky injectors. I have heard mixed things about using techron and if it actually does anything or not for the injectors on the n54 (because it’s DI), but it really couldn’t hurt to try because it’s cheap and easy. I also remember about 3 weeks ago when I was getting misfires, thrown in with those codes was an o2 sensor code, but it only has shown up that one time. Could bad o2 sensors also be a possibility because I know that the lambda sensors are related to those. I also suspect that my car is running rich because on startup it smells strongly of fuel. I’ll include a screenshot of the code that it threw on MHD.
Also… you said that the v9 maps weren’t great for you. Which maps would you recommend running and have worked well in the past?

[stuartbrown.e90]

I just checked and all my injectors are index 11. I feel like those generally are almost as good as the 12 ones, but could still have problems.

[whyzee125]

Index 11s are pretty reliable but they’re also very old at this point. Like, at least 10 years old.

You have a ton of symptoms pointing directly to bad injectors.

I had a single index 12 fail on cylinder 2 and the car still ran great but had:
1) fuel smell most prominent at startup
2) shooting fuel out the exhaust on cold start
3) wet plug and grimy coil
4) lambda slow to recover in logs

If it were me, my next step after a bottle of Techron would be: