[ColtonChoi]

Hello guys.. I am a newbie..just bought an e92 n54 335i about 2 months..and this car drives me crazy enough..

1st day I went deep throttle and got the half engine light when over 3-4k rpm... but the light disappeared when I restarted the car..So I sent it to garage.. the technician told me 30FF code was found.. had checked the vacuum line by smoke.. seems nothing leak.. they suggested me to replace 2 pressure converters.. and I told them to replace the VRSF's charge pipe with bov, cone intake and bigger intercooler..I thought everything is gonna be ok.. but it isn't..

Still find the half engine light when I go deep throttle over3300rpm.. no sound from the bov..no sound from the wastegate.. no white smoke observed from the exhaust..just a bit loud from the exhaust.no acceleration clearly between 50-90km/h.. until over 100... I can feel some power is going up slightly but not fast.. just like an N/A.. I feel there is some power loss.. just feel like I am a 3-legs horse.. the technician told me maybe 1 high boost turbocharger is dead.. highly recommend me to replace the turbos...well you know.. the labour fee will cost a lot.. the money for my stage2+ planning is gone..all gone for the repair fee..and now I am wondering I should have listened to him? Is there the other way to check before the worse case?

08' e92 335i n54 AT
OEM..

Really sad.. I hope you guys can give me some suggestions, thank you.

[techwhiz]

Check vacuum lines.
I think you aren't reaching the boost target. I might be wrong.

[ColtonChoi]

Originally Posted by rap17ka7a

30FF is very popular and absolutely shit code to deal with.

If you have access to MHD to log then you can see what is the Wastegate duty cycle and how far off you are from the boost target. If one or both wastegates are not closing properly due to solenoid/s failing then you just need to replace them. Changing vacuum lines is always a good thing to do anyway! Also might worth checking the PCV valve as I've heard they are prone to fail sometimes and you can't really check that part of the engine with a smoke test.

My problem was simple - wastegate rattle. I did replace all vacuum lines just in case as well.

If your car is stock then the problem must be obvious and I will tell you why. When I was installing my DCI I disconnected the diverter valves and when I was connecting them back I must have forgotten to twist one of the connections back in place. I was boosting absolutely fine and the car was running perfectly fine. 1 month later I managed to put JB4, straight to map 5 and on the first serious pull the diverter pop'ed out!
Conclusion is... stock diverter valves and charge pipe are absolutely fine for stock engines... even not fitted properly!!!

Which MHD package I need to purchase for reading the MHD log?

[ColtonChoi]

Originally Posted by techwhiz

Check vacuum lines.
I think you aren't reaching the boost target. I might be wrong.

Hope it is about the vacuum line problem..

[Emilime75]

What is this shop you're taking it to?

Are they familiar with, and have a good understanding and experience with N54s?

Throwing a bunch of parts at it before determining what the problem is is foolish. Granted, a 30ff could have been from damage or a loose connection from the IC or CP, but that's still not diagnosing the problem and determining if those replaced parts will actually fix it. On top of that, if the shop isn't familiar with these cars/engines, you could easily have another poor connection/boost leak at one of the parts they installed resulting in the same symptoms and code.

30ff generally means a boost leak or failed turbo/s.

PS What are "pressure converters", and did they replace them?