[BigBambu]

I've been searching/googling around and I can't get a solid idea on what may be the case.

When the car is idling, I feel a slight blip of a shudder in the car. This action isn't reflected in RPMs, doesn't make any under the hood noise (that I can hear) and it happens while Cobb is installed and uninstalled. I've remedied misfires with coil replacements, and this doesn't feel like that.

When Cobb is installed, the only code I have been throwing is P2AAF which has never been uncommon. Performance feels okay but I haven't gone WOT since my last data log awhile ago. The fuel pump is located beneath the driver seat correct? Is this an HFPF on it's way out?

If is there anything I can do to get a better idea on what the issue may be please share. Will pulling some fresh datalogs help pin point the issue?

Anything will help at this point, much appreciated.

[I6+TT=FTW]

Originally Posted by BigBambu

I've been searching/googling around and I can't get a solid idea on what may be the case.

When the car is idling, I feel a slight blip of a shudder in the car. This action isn't reflected in RPMs, doesn't make any under the hood noise (that I can hear) and it happens while Cobb is installed and uninstalled. I've remedied misfires with coil replacements, and this doesn't feel like that.

When Cobb is installed, the only code I have been throwing is P2AAF which has never been uncommon. Performance feels okay but I haven't gone WOT since my last data log awhile ago. The fuel pump is located beneath the driver seat correct? Is this an HFPF on it's way out?

If is there anything I can do to get a better idea on what the issue may be please share. Will pulling some fresh datalogs help pin point the issue?

Anything will help at this point, much appreciated.

Even after software upgrade, plug replacement, and walnut blasting of the intakes, I do still notice a "slight blip" as you said at idle. From what I have read and found out talking to my SA, the N54 idle just isn't that smooth to begin with.

Let me guess, it almost feels like a mini misfire, right? Now that I have a muffler delete I can even hear mine a little, but you don't notice a change in the rpms.

I just think that you have to have brand new plugs, brand new injectors, brand new coils, and freshly walnut blasted intake valves to not have any little "blips".

Unless you are throwing misfire codes, I'm sure it is probably normal.

[BigBambu]

Mini-misfire with no RPM change describes it perfectly. I kept away from saying misfire just because these forums are filled with misfire problems and solutions. It may be around 1 1/2 since I had the valves cleaned and injectors / plugs replaced, so I guess it makes sense.

I recently had my water pump replaced so I was worried that there was an issue with that repair.

Thanks for the reply man, puts a little comfort in this N54 owners heart. Haha.

[I6+TT=FTW]

Originally Posted by BigBambu

Mini-misfire with no RPM change describes it perfectly. I kept away from saying misfire just because these forums are filled with misfire problems and solutions. It may be around 1 1/2 since I had the valves cleaned and injectors / plugs replaced, so I guess it makes sense.

I recently had my water pump replaced so I was worried that there was an issue with that repair.

Thanks for the reply man, puts a little comfort in this N54 owners heart. Haha.

Glad I could help. Anyone else can chime in to confirm or deny the normality of your issue.

[gatorheel]

i get that bullshit too. annoying. 2aaf or whatever as well.

i figure fuck it, just keep rippin it until something breaks ... this car likes to go fast

[dirtmaster666]

If you are able to see what your afr does during this stutter that would be cool and like to know what your afr says. Mine does same thing but my afr tags 20:1 when this happens. Pretty much came to the conclusion, my turbo seals are gone which fouls my o2's once and a while

[I6+TT=FTW]

Originally Posted by dirtmaster666

If you are able to see what your afr does during this stutter that would be cool and like to know what your afr says. Mine does same thing but my afr tags 20:1 when this happens. Pretty much came to the conclusion, my turbo seals are gone which fouls my o2's once and a while

Once I get a COBB I'll let definitely watch for that.

[charrigan]

I get this same issue. It's more noticeable and happens more on hotter days. I thought it was carbon build up or bad plugs. I'll have both addressed soon and we will see if this changes at all.

[E90Company]

I've noticed that most people jump straight away to assuming carbon buildup is the cause of their rough running N54. This is rarely the case. Only if it's really bad buildup will you start to notice slight hesistation. Most likely it's a weak component of your ignition system that needs replacing (plugs and coils), or a fuel system component such as injectors, or more rarely nowadays, the HPFP. A leak in your vacuum system could also cause this.

[135Hoser]

I had the same problem. After doing plugs/coils/injectors (coded and adaptations reset in INPA) it got a little better.

After replacing all my o2 sensors, it went away. Car has been running like a champ since.

[corbs09]

OP change your plugs.. mine did this and plugs fixed it!

[TexE90]

I've done plugs, coils, and intake blast... My hiccup is still there. I'll try to grab a log of my AFR when it happens. Would make sense it's a bad O2 sensor if my AFR spikes when the hiccup happens.

[enrita]

Afr spikes normally happen because u are missfiring. How old are the injectors?
Could be one of them is on its way out.
The code u are getting is pretty standard alone does not mean anything . (Fuel pump plausability)

[Jeff@TopGearSolutions]

First thing that came to mind is leaky injector.

Easiest way to find the culprit is to pull your spark plugs out. They can tell you a lot about what is happening with your car. As platforms and technology grows we keep forgetting to go back to basics and stop relying on computers.

If 1 or more is black with fuel it is likely an indication of a leaky injector.

If 1 or more is black with oil it could be an indication of a leaky valve cover gasket.

[dirtmaster666]

I was Just asking for an afr reading because seems like for me when I get this. It's that my turbo seals are leaking which fouls o2's which makes car run super lean then eventually afr comes back and runs normal

[Bluesnake01]

Mine does it as well, read somewhere else that its normal. Did it when I first bought, did it before the plugs and after the plugs. My brothers 335i does it as well. Like someone said, it mostly does it when its hot but its not a common thing nor affect the performance/driveability.

So I wouldn't be worry about it.

[gatorheel]

Originally Posted by dirtmaster666

I was Just asking for an afr reading because seems like for me when I get this. It's that my turbo seals are leaking which fouls o2's which makes car run super lean then eventually afr comes back and runs normal

I will also try to get some logs of this. Data logging idle... First time for everything!

[BigBambu]

Thanks for the comments everyone. I took a quick video of my exhaust note which might help in understanding what I, and maybe some of you, are experiencing.

Originally Posted by Jeff@TopGearSolutions

First thing that came to mind is leaky injector.

Easiest way to find the culprit is to pull your spark plugs out. They can tell you a lot about what is happening with your car. As platforms and technology grows we keep forgetting to go back to basics and stop relying on computers.

If 1 or more is black with fuel it is likely an indication of a leaky injector.

If 1 or more is black with oil it could be an indication of a leaky valve cover gasket.

Thanks Jeff, your insight/experience is always appreciated. Once I buy the required socket, I'll give them a look.

Originally Posted by enrita

Afr spikes normally happen because u are missfiring. How old are the injectors?…

Once I find my service records I will be able to get an exact mileage on the injectors. I'm pretty sure they were replaced once before, though I could be wrong.

Originally Posted by corbs09

OP change your plugs.. mine did this and plugs fixed it!

Definitely going to be pulling my plugs once I get the required socket & extension. Appreciate the input man.

Quick video: