Boost Leak?

dakotap80 · 06-24-2018, 03:31 PM

Hello guys, sorry for another thread about this. I made a couple of logs and it shows the boost target being 16-17 PSI, and it'll initially hit that at around 3300 RPM, but it steadily drops from there all the way down to 9 PSI at 6200 RPM even though the target is at 15.9 PSI.
Does this mean I have a boost leak? I am running MHD 1+ on the stock CP so that's on my list. Any help is appreciated, sorry if this topic has been beaten to death!

jeddo45 · 06-24-2018, 04:55 PM

Quote:

Originally Posted by dakotap80

Hello guys, sorry for another thread about this. I made a couple of logs and it shows the boost target being 16-17 PSI, and it'll initially hit that at around 3300 RPM, but it steadily drops from there all the way down to 9 PSI at 6200 RPM even though the target is at 15.9 PSI.
Does this mean I have a boost leak? I am running MHD 1+ on the stock CP so that's on my list. Any help is appreciated, sorry if this topic has been beaten to death!

Limp mode?

Boost tapers off on the higher RPMs starting at about 6200 RPMs so that's normal.

If your getting limp mode then you definitely do.

dakotap80 · 06-24-2018, 05:33 PM

No limp mode or codes, just seems worrying to be 5+ PSI below target. The taper doesn't start at high RPM's, it peaks around 3300 and drops linearly from there.
Log attached.

RocketSurgeon · 06-25-2018, 04:44 AM

A boost leak is a very real possibility. I've had 3 n54 cars, and every one of them had a boost leak.
Boost solenoids and vacuum lines can also cause underboost.
It's well worth the time to run a boost leak test.
Also post up your WGDC with the log, that's helpful for diagnostics.

dakotap80 · 06-25-2018, 10:26 AM

I'l probably be ordering a new boost solenoid here in the next little bit. Vacuum lines seem like they could be a PITA but I may end up doing those as well.

Here is the original log with WGDC%, also a new log I made yesterday, the WGDC is at 67% at the center peak.

RocketSurgeon · 06-25-2018, 11:09 PM

You have a whole bunch of timing corrections there...

Vacuum lines aren't too bad, I replaced every single rubber line on my car in about 90 minutes.
I would still want to run a boost leak test.

dakotap80 · 06-26-2018, 10:19 AM

Yeah ignition coils are also on my list haha. That doesn’t sound too bad at all actually.

Bimmer_Engineer · 09-07-2018, 07:38 AM

Did you ever solve this? I'm dealing with something similar and I've already replaced the vacuum lines and checked all of the boost piping and connections. I'm thinking of going to boost solenoids next.

06-24-2018, 03:31 PM	#1
dakotap80 Private 27 Rep 72 Posts Drives: 2011 E90 335i xDrive Join Date: May 2017 Location: Montana iTrader: (0)	Boost Leak? Hello guys, sorry for another thread about this. I made a couple of logs and it shows the boost target being 16-17 PSI, and it'll initially hit that at around 3300 RPM, but it steadily drops from there all the way down to 9 PSI at 6200 RPM even though the target is at 15.9 PSI. Does this mean I have a boost leak? I am running MHD 1+ on the stock CP so that's on my list. Any help is appreciated, sorry if this topic has been beaten to death!
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06-24-2018, 05:33 PM	#3
dakotap80 Private 27 Rep 72 Posts Drives: 2011 E90 335i xDrive Join Date: May 2017 Location: Montana iTrader: (0)	No limp mode or codes, just seems worrying to be 5+ PSI below target. The taper doesn't start at high RPM's, it peaks around 3300 and drops linearly from there. Log attached. Attached Images
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06-25-2018, 04:44 AM	#4
RocketSurgeon Lieutenant 264 Rep 459 Posts Drives: 2008 135i Manual, CBR650F Join Date: Jan 2017 Location: NC iTrader: (0)	A boost leak is a very real possibility. I've had 3 n54 cars, and every one of them had a boost leak. Boost solenoids and vacuum lines can also cause underboost. It's well worth the time to run a boost leak test. Also post up your WGDC with the log, that's helpful for diagnostics.
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06-25-2018, 10:26 AM	#5
dakotap80 Private 27 Rep 72 Posts Drives: 2011 E90 335i xDrive Join Date: May 2017 Location: Montana iTrader: (0)	I'l probably be ordering a new boost solenoid here in the next little bit. Vacuum lines seem like they could be a PITA but I may end up doing those as well. Here is the original log with WGDC%, also a new log I made yesterday, the WGDC is at 67% at the center peak. Attached Images
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06-25-2018, 11:09 PM	#6
RocketSurgeon Lieutenant 264 Rep 459 Posts Drives: 2008 135i Manual, CBR650F Join Date: Jan 2017 Location: NC iTrader: (0)	You have a whole bunch of timing corrections there... Vacuum lines aren't too bad, I replaced every single rubber line on my car in about 90 minutes. I would still want to run a boost leak test.
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06-26-2018, 10:19 AM	#7
dakotap80 Private 27 Rep 72 Posts Drives: 2011 E90 335i xDrive Join Date: May 2017 Location: Montana iTrader: (0)	Yeah ignition coils are also on my list haha. That doesn’t sound too bad at all actually.
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09-07-2018, 07:38 AM	#8
Bimmer_Engineer Lieutenant Colonel 1044 Rep 1,667 Posts Drives: 2007 335i Join Date: May 2018 Location: Louisiana iTrader: (0) Garage List 2008 Porsche Boxster [0.00] 2016 Mercedes Benz ... [0.00] 2007 BMW 335i [9.50]	Did you ever solve this? I'm dealing with something similar and I've already replaced the vacuum lines and checked all of the boost piping and connections. I'm thinking of going to boost solenoids next.
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