[PuNiShEr]

Has been resolved!!! (For Now) Anyway, I've had a missfire issue with my car since May of last year! Typical comes and goes, but more intrestingly it would get worse during cold weather. Little did I realize, I was loosing power all this time. After driving a 335 seadan loaner for 28 days....It was like the loaner had a tune on it. My car has lost that much power. The past month or so here in Virginia we have had really cold weather....Lows in the 20s. Went to start the car the morning of Jan 2nd and it just took a shit. Finally gave up. Every light came on (SES / Engine Mal Func Lights) you name it. White smoke poured out the exhaust and it sounded like a diesel.

What was changed:

They found which is becoming the norm for the N54, carbon build up in and around the intake valves. / My fuel pump had also failed (My second HPFP in as many cars! ) / They replaced all six injectors / All six ignition coils / All six spark plugs / and a new valve cover which has a redesigned crank case breather system. The car was also updated to the latest and greatest programing.... 32.1.

Performance:

Runs like new again!!

Much props goes out to Mike, Terry, Bob, and Jesse at Casey BMW of Newport News Virginia for getting this right.

[branabolic]

damn... how many miles on the car?

[GME92]

I just had the EXACT same things happened to my car 2 weeks ago and all those things you listed were changed on my car as well.

[Bubbles]

Could this carbon buildup issue be this year's fuel pump?

[scheherazade]

Is this carbon buildup related to the blowby oil that normally a catch can is supposed to stop?

And if it is, I'd hate to install a catch can, and just have the same problem later/less-frequently, but have the dealer say it's the catch can's fault :-\

-scheherazade

[sambonator]

Did this become a BMW PUMA case before they were able to completely fix the cars? Did you guys have a tune?

[Sniz]

does the carbon buildup have anything to do with how hard/not hard you drive your car?

[scheherazade]

Originally Posted by Sniz

does the carbon buildup have anything to do with how hard/not hard you drive your car?

(note : I'm no authority, so if I get some of this wrong, don't shoot me. I'd rather someone who knows better comment. Que shiv or whoever...)

You should have more blow-by gas making its way into your intake with more boost, so sure... and that gas is carrying carbonated oil, which you are later ingesting through the turbo, and is blown into your intake and over your intake valves.

BUT...

Generally carbon buildup is just residual crap that sticks to the valves during normal operation... every engine gets it.
It just so happens that if gasoline is injected into the intake manifold[-ish area], it will flow over the valves on the intake stroke and wash off some of the buildup.

The N54 is direct injected into the cylinder, so no gasoline flows over the intake valves, only air, so there is nothing washing of the buildup from the intake valves.


This is a related point to what I asked on the meth injection thread. (Can fuel system treatment be injected into the intake manifold with the meth to keep the intake valves clean?)


-scheherazade

[Vince@ V K Motorwerks]

I notice that our cars will routinely misfire in very cold temps, I have run other members car and my own to test this theory and was able to get them to misfire. I see this usually when temps are 10f or below. It is probably due to the density of the air. You can run slightly less agressive boost and avoid this issue.

[O-cha]

Originally Posted by scheherazade

Is this carbon buildup related to the blowby oil that normally a catch can is supposed to stop?

And if it is, I'd hate to install a catch can, and just have the same problem later/less-frequently, but have the dealer say it's the catch can's fault :-\

-scheherazade

It'll never catch it all, if anything just delay the inevitable. Depending on the car you can just vent the CCV to atmosphere. Never got to deep into it with the 335, someone should though, probably be one of the better little things to do for your car.

[BMW_TT]

Any way to detect this before it gets worse?

[TMR]

Well this is another advantage to the Meth kits coming out... It can clean your valves while it gives you more power.

[ScottB4857]

This post couldn't come at a better time. Took my 07 335i in three days ago for a weird misfire issue. Today dealer calls to say code was misfire on cylinder 5. replaced coil, plugs, etc with no help. Mentioned the carbon build up problem and now talking about replacing cylinder head. I will tell them to call the guys up in Newport News for some tips on how to solve.

Big question is - Does the new valve cover solve the problem? I don't need to go through this crap every 20-25k miles. Car currently has around 23.5k miles.

Thanks,
Scott

[marconi118]

PuNiShEr what build date whas your car?
breather
I have 06/07 with 15K miles and wonder if I have the defective crank case breather system

[joec500]

Originally Posted by ScottB4857

This post couldn't come at a better time. Took my 07 335i in three days ago for a weird misfire issue. Today dealer calls to say code was misfire on cylinder 5. replaced coil, plugs, etc with no help. Mentioned the carbon build up problem and now talking about replacing cylinder head. I will tell them to call the guys up in Newport News for some tips on how to solve.

Big question is - Does the new valve cover solve the problem? I don't need to go through this crap every 20-25k miles. Car currently has around 23.5k miles.

Thanks,
Scott

I am sure once they remove the Valve cover they will see the carbon buildup, if there is any in your case..... Good Luck and keep us updated...I am in the same mileage level as yourself. BMW is installing a new Camshaft in my car, so I have the same issue I hope they clean the stuff too.

[Kbueno]

+1 : Is there any more info on the revised valve cover...were the old ones prone to leakage.

[sd390r]

So many weak spots with the n54 LOL

[Fraggy]

I get misfires everymorning when its cold. My dealership didnt even replace the plugs and coils, they just the one that the code said misfired to a different cylinder. So the problem still persists, and I dont even have a tune.

[sd390r]

ive been through 3 fuel pumps but never a misfire or any probs with sparks/coils/injectors

[BayernMuenchen]

I had an issue with a consistent misfire in one cylinder (4). Took BMW a month to try changing the sparkplug which fixed it...

[sambonator]

I had consistent misfire on a cylinder.. they replaced the injector and fixed the problem.

[mwahlert]

how are you guys determining that the car is misfiring? is it blowing codes?