[cizsak11]

I've got a 2007 335i Coupe. I have half the power I use to, with lots of white smoke coming from the exhaust. Here are the errors codes during the diagnostics: 30FF, 2C7B, 2C3D. From the research that I have done so far, it seems that the turbo bearings might have gone out. Please ask me questions for more clarification.

Any help is greatly appreciated.

[JDuke335i]

Originally Posted by cizsak11

I've got a 2007 335i Coupe. I have half the power I use to, with lots of white smoke coming from the exhaust. Here are the errors codes during the diagnostics: 30FF, 2C7B, 2C3D. From the research that I have done so far, it seems that the turbo bearings might have gone out. Please ask me questions for more clarification.

Any help is greatly appreciated.

Are the turbos whining , r making any noises ? Have you done any work to the car lately ? The 2c7b is a o2 codes

[cizsak11]

I noticed maybe a bit more noise from it spooling up prior to the power loss. However, now there is no sound.

[limitdown]

I would try cheaper fixes and tests before going down the route of replacing turbos.
30FF is boost leak, which can be occur from dozens of places
The other codes are related to the O2 sensors

First track down the boost leak. Search for $10 smoke test. That's the method I used to find my boost leaks (5 different places!).

The O2 sensors are about $150 a piece for Bosch branded ones. They're working very well for me.


I almost always try cheaper fixes first, before going for an expensive one.

[MashoodSharaf]

The 30FF code indicates boost leak. It could be vacuum lines or maybe your chargepipe. Make sure to see for cracks or loose/disconnected lines. Also check the ends of the chargepipe to make sure it's not broken. Try doing a smoke test for that one

[924er]

Is the white smoke coming out when you let off the gas? Could be your turbo seals and a boost leak.

[cizsak11]

It was white smoke, and could a boost leak cause such a significant amount of power loss? Also, are turbo seals common to go out?

[Jklad]

Originally Posted by cizsak11

It was white smoke, and could a boost leak cause such a significant amount of power loss? Also, are turbo seals common to go out?

Yes, a boost leak can cause a significant amount of power loss. Don't freak out, just go from cheapest most likely fix and work your way from there.

[limitdown]

With no boost, you'll lose about 100 horsepower.
The two most likely causes are vacuum lines cracking, breaking, flaking apart and a cracked charge pipe is the other most common cause.

[cizsak11]

Where do I start looking in the vacuum lines for a crack? or for that matter a charge pipe that is cracked? Any pictures for a better idea?

[Turbo_power4ever]

Originally Posted by cizsak11

Where do I start looking in the vacuum lines for a crack? or for that matter a charge pipe that is cracked? Any pictures for a better idea?

Theres a thread where they use a cigar I believe and a pvc cap hooked up to the intake. Lol with a fluid transfer pump, and the smoke will reaveal leaks. The vaccum lines should be replaced. Its only about 20$ worth of silicone line, and you can do it yourself. Its kinda of a pain, but not that bad. Use the search for vaccum line replacement. Hopefully its a leak and not your turbos.

[///Mposter]

Here is what I made for someone on another forum.

[BeastMode335i]

Pretty sure it's your turbo(s) man.. I'm in the same boat and I throw those same codes minus the boost one, and my speculation on it was that when i clear the codes and start the car the codes stay cleared, until the white smoke comes billowing out then it triggers the O2 sensors because they are basically being fogged out with smoke.. Just my input anyways..

[cizsak11]

///M poster thanks for the diagram! Turbopower thanks for tip! My final question before I go and start this investigation; could white smoke start from a vacuum leak?

[chmerlinn]

Originally Posted by cizsak11

///M poster thanks for the diagram! Turbopower thanks for tip! My final question before I go and start this investigation; could white smoke start from a vacuum leak?

Unsure about the white smoke, but check these two threads out.. I am doing my vac lines and boost solenoids this weekend (my car sounds like chewbacca), solid colour coded diagram on the first link here and a good guide here

Hope that helps, GL.

[Craz]

I would be concerned with the white smoke. How white is it? More blue or like a true cloud like white?

Vacuum leaks -- There are two canisters behind the passenger headlight. Take the hose off the top of the canister and put your finger on the top hole of the canister. It will be very little vacuum, but should be there at idle. If not, follow the vacuum lines from the bottom of the canister over towards the throttle body. If you have a leak, you will find it.

Turbo's - Take your air box off. The two air inlet tubes that go out from the box actually go to your turbo inlets. I would listen in those tubes and see if you hear any significant noise like squealing, squeaking or medal grind (at idle or very low rev). If your bearings are bad, the propeller blades will be scrapping in most cases or the bearing is just starting to go bad and will squeal a bit.. kinda like a wheel bearing. You would need to really beat these up for this to happen though, or never change your oil, run low on oil a lot, or have SEVERAL miles on them.

Good luck and please let us know about the smoke. Kinda interested in your discoveries.