Time for new turbos?

M1 Tanker · 05-20-2015, 06:54 PM

i have an 08 335i MT that's at 143k (lots of highway road trips and commutes) and a few month back I started throwing 30FF codes for low boost pressure. After running checks for leaks and replacing a stock charge pipe that had a small leak where it met the diverter valve(which was also replaced) and all the vacuum lines I am still going into limp mode at the high end of second gear or if I try to accelerate from about 2500 rpm to 3500 in 4th. I recently noticed I'm starting to get some of the turbo whine/siren noise especially on cold starts. So my question is at this point does it look like it's time for turbo replacement? Apart from what's listed above the car is in great shape with only normal issues like the water pump and O2 sensors. Only engine mod I have is a Stett CAI and it has never been tuned.

Edit: I've also tested the pressure converters (boost solenoids) and they are functioning normally

mike@x-ph.com · 05-20-2015, 11:29 PM

If you have no leaks and the boost solenoids are good then yea it is time for new turbos.

fredcase · 05-20-2015, 11:37 PM

How do you test the boost solonoids? I might be in the same boat as you.

M1 Tanker · 05-21-2015, 04:08 AM

http://www.n54tech.com/forums/showthread.php?t=13114

Check out that link, the parts to test the solenoid were about $30 total from advanced auto parts.

Unless someone has any other info to add thinking it may not be turbo related are there any N54 turbo replacement DIY's posted anywhere? I have the Bentley manual but I'm a little unclear about lifting the front end of the engine up. I do believe that is part of the process?

Sgop335 · 05-21-2015, 05:50 AM

Quote:

Originally Posted by fredcase

How do you test the boost solonoids? I might be in the same boat as you.

Very simple. There is a hose running between the 2 solenoids, remove that. Check each solenoid individually. Plug one barb and connect a vacuum gage to other. So its all plugged now and the car can be started.

At idle after a min or so, the gage should read -14 to -18 in hg. Same with the other solenoid. They can also be tested w no load at 3k rpm. Vacuum numbers are 17 -20in.

Jaronbwall · 05-21-2015, 07:52 AM

Quote:

Originally Posted by mike@x-ph.com

If you have no leaks and the boost solenoids are good then yea it is time for new turbos.

Time for new RBs I think!

05-20-2015, 06:54 PM	#1
M1 Tanker New Member 0 Rep 13 Posts Drives: 08' 335i Coupe Join Date: May 2011 Location: PA iTrader: (0)	Time for new turbos? i have an 08 335i MT that's at 143k (lots of highway road trips and commutes) and a few month back I started throwing 30FF codes for low boost pressure. After running checks for leaks and replacing a stock charge pipe that had a small leak where it met the diverter valve(which was also replaced) and all the vacuum lines I am still going into limp mode at the high end of second gear or if I try to accelerate from about 2500 rpm to 3500 in 4th. I recently noticed I'm starting to get some of the turbo whine/siren noise especially on cold starts. So my question is at this point does it look like it's time for turbo replacement? Apart from what's listed above the car is in great shape with only normal issues like the water pump and O2 sensors. Only engine mod I have is a Stett CAI and it has never been tuned. Edit: I've also tested the pressure converters (boost solenoids) and they are functioning normally
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05-20-2015, 11:29 PM	#2
mike@x-ph.com BimmerPost Supporting Vendor 24190 Rep 190,802 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	If you have no leaks and the boost solenoids are good then yea it is time for new turbos. __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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05-20-2015, 11:37 PM	#3
fredcase Captain 261 Rep 776 Posts Drives: Bmw=trash Join Date: Mar 2014 Location: Noyb iTrader: (1)	How do you test the boost solonoids? I might be in the same boat as you.
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05-21-2015, 04:08 AM	#4
M1 Tanker New Member 0 Rep 13 Posts Drives: 08' 335i Coupe Join Date: May 2011 Location: PA iTrader: (0)	http://www.n54tech.com/forums/showthread.php?t=13114 Check out that link, the parts to test the solenoid were about $30 total from advanced auto parts. Unless someone has any other info to add thinking it may not be turbo related are there any N54 turbo replacement DIY's posted anywhere? I have the Bentley manual but I'm a little unclear about lifting the front end of the engine up. I do believe that is part of the process?
	Appreciate 0 Quote