[MrS3anW]

I recently had a serious turbo whine on my N54 335i and after messing around under the hood for a bit I noticed if I unplug one of the vacuum canisters the whine goes away completely but when it’s plugged in it’s so bad I can’t drive it. It does this hot or cold even after the car has been running for 30 minutes. One of the nipples was broken off by the previous owner so I thought maybe it was that connection so I ordered a new canister and while I waited for it to arrive I just unplugged the line from the top of that canister so I could drive it. The canister arrived today so I threw it on and connected the line and now the whine is back with a vengeance. I have gone through countless threads and forums and haven’t found any really helpful answers so Here I am. Also, as of about a month or two ago I have been having the car go into limp mode if it goes past 3500rpm and it’s feeling sluggish, I hooked the car up to a snap on scanner and got the following codes:

2CAA- ENGINE ELECTRONICS:OXYGEN SENSOR BEFORE CATALYTIC CONVERTER: TEMPERATURE

2C7C- O2 SENSOR AFTER CATALYST 2, SIGNAL

29EO- MIXTURE CONTROL

29C3E- O2 SENSOR BEFORE CATALYST 2, CABLE FAULT

2CAB- ENGINE ELECTRONICS: OXYGEN SENSOR BEFORE CATALYTIC CONVERTER: TEMPERATURE

29CF- COMBUSTION MISFIRE ON CYLINDER 3

2C2D- O2 SENSOR BEFORE CATALYST, THRUST CHECK

30FF- CHARGING PRESSURE CONTROL, BOOST PRESSURE TOO LOW

2C7B- O2 SENSOR AFTER CATALYST, SIGNAL

2C3D- O2 SENSOR BEFORE CATALYST, CABLE FAULT

P013E- O2 SENSOR DELAYED RESPONSE - RICH TO LEAN(BANK 1 SENSOR 2)

P014A- O2 SENSOR DELAYED RESPONSE - RICH TO LEAN(BANK 2 SENSOR 2)

I need all the help I can find on any of these issues and it would mean the world to me if I could get a little help on here.

[RoughKnight]

change your o2 sensors and try again, seems like a good place to start before u tackle the 30ff code

[Saif2018]

Originally Posted by MrS3anW

I recently had a serious turbo whine on my N54 335i and after messing around under the hood for a bit I noticed if I unplug one of the vacuum canisters the whine goes away completely but when it’s plugged in it’s so bad I can’t drive it. It does this hot or cold even after the car has been running for 30 minutes. One of the nipples was broken off by the previous owner so I thought maybe it was that connection so I ordered a new canister and while I waited for it to arrive I just unplugged the line from the top of that canister so I could drive it. The canister arrived today so I threw it on and connected the line and now the whine is back with a vengeance. I have gone through countless threads and forums and haven’t found any really helpful answers so Here I am. Also, as of about a month or two ago I have been having the car go into limp mode if it goes past 3500rpm and it’s feeling sluggish, I hooked the car up to a snap on scanner and got the following codes:

2CAA- ENGINE ELECTRONICS:OXYGEN SENSOR BEFORE CATALYTIC CONVERTER: TEMPERATURE

2C7C- O2 SENSOR AFTER CATALYST 2, SIGNAL

29EO- MIXTURE CONTROL

29C3E- O2 SENSOR BEFORE CATALYST 2, CABLE FAULT

2CAB- ENGINE ELECTRONICS: OXYGEN SENSOR BEFORE CATALYTIC CONVERTER: TEMPERATURE

29CF- COMBUSTION MISFIRE ON CYLINDER 3

2C2D- O2 SENSOR BEFORE CATALYST, THRUST CHECK

30FF- CHARGING PRESSURE CONTROL, BOOST PRESSURE TOO LOW

2C7B- O2 SENSOR AFTER CATALYST, SIGNAL

2C3D- O2 SENSOR BEFORE CATALYST, CABLE FAULT

P013E- O2 SENSOR DELAYED RESPONSE - RICH TO LEAN(BANK 1 SENSOR 2)

P014A- O2 SENSOR DELAYED RESPONSE - RICH TO LEAN(BANK 2 SENSOR 2)

I need all the help I can find on any of these issues and it would mean the world to me if I could get a little help on here.

Time whine is most likely caused by a boost leak, if it goes away after disconnecting vacumn cannisters.

Follow this guide to resolve 30FF code.

https://bmwtuning.co/bmw-n54-30ff-en...-repair-guide/

It looks like your O2 sensors are shot, or not wired in properly. Need to be checked and replaced.

If you have MHD, you can log and check various parameters too.

[MrS3anW]

Originally Posted by Saif2018

Time whine is most likely caused by a boost leak, if it goes away after disconnecting vacumn cannisters.

Follow this guide to resolve 30FF code.

https://bmwtuning.co/bmw-n54-30ff-en...-repair-guide/

It looks like your O2 sensors are shot, or not wired in properly. Need to be checked and replaced.

If you have MHD, you can log and check various parameters too.

I am under the impression that my turbos are shot, unplugging the lines from the turbos causes the whine to go away. If I’m correct when those lines are disconnected the wastegates are left wide open so the exhaust gasses bypass the turbos. I just had to replace my battery and I learned when your battery goes bad on the e9x the first thing to go is the coolant system for the turbos causing them to fail sooner. I have gone through all the connections and checked all my lines for cracks or leaks and didn’t find anything.

[Mustafa.e92]

Turbos are shot bro. I went 1 week tryna find something else to blame when it happend to my car . Pull ur inlets off and check for shaft play. Front one you have to pull the fan out to do it and 2 bolts and she slides right off. Back one you gotta pull the downpipes pita

[Saif2018]

Originally Posted by MrS3anW

I am under the impression that my turbos are shot, unplugging the lines from the turbos causes the whine to go away. If I’m correct when those lines are disconnected the wastegates are left wide open so the exhaust gasses bypass the turbos. I just had to replace my battery and I learned when your battery goes bad on the e9x the first thing to go is the coolant system for the turbos causing them to fail sooner. I have gone through all the connections and checked all my lines for cracks or leaks and didn’t find anything.

Worst case, yeah. Have you checked datalogs WGDC?

[Emilime75]

Originally Posted by Saif2018

Time whine is most likely caused by a boost leak, if it goes away after disconnecting vacumn cannisters.

Follow this guide to resolve 30FF code.

https://bmwtuning.co/bmw-n54-30ff-en...-repair-guide/

It looks like your O2 sensors are shot, or not wired in properly. Need to be checked and replaced.

If you have MHD, you can log and check various parameters too.

It sounds like he's saying there is a whine at idle, there shouldn't be any boost pressure at idle.

I'd start by replacing all of the vac lines and thoroughly checking every component/nipple. If the canister/s were damaged, others might be, as well.

Next work through O2 sensor diagnosis and repair/replacement, as needed.

OP, what's the back story on the car? How long have you owned it? When did this problem start? You say the canister nipple was broken off by the previous owner...this should've had symptoms when you bought it.

[Saif2018]

Originally Posted by Emilime75

It sounds like he's saying there is a whine at idle, there shouldn't be any boost pressure at idle.

I'd start by replacing all of the vac lines and thoroughly checking every component/nipple. If the canister/s were damaged, others might be, as well.

Next work through O2 sensor diagnosis and repair/replacement, as needed.

OP, what's the back story on the car? How long have you owned it? When did this problem start? You say the canister nipple was broken off by the previous owner...this should've had symptoms when you bought it.

My thoughts exactly, both the O2 issues and Boost leak issues need to be sorted.

If the whine is at idle it could be auxiliary belts/pulleys causing it.