Proper Boost Leak Testing Method?

Zasquatch · 04-12-2011, 08:08 AM

Hey guys,

I know this has probably been discussed before my time, but what is the proper way to test for boost leaks on the N54? I know on other cars it's as simple as hooking up a PVC end cap directly to the turbo inlet/outlet and pressurizing the system to 20 psi.

Our cars are not that simple, and getting to the turbos is a real PITA... I was thinking of plugging one intake pipe and pressurizing the system through the other, but those intake pipes aren't designed for boost...

The other option is getting to the hot side of the intercooler and pressurizing from there... but that is one of the connections I want to test for leaks.

Anyone have a good method?

Sniz · 04-12-2011, 08:47 AM

I did a DIY on this years ago if you can find it.

basically you want to pressurize from the hot side of the intercooler.

Zasquatch · 04-12-2011, 08:54 AM

Quote:

Originally Posted by Sniz

I did a DIY on this years ago if you can find it.

basically you want to pressurize from the hot side of the intercooler.

Cool, thanks. I just noticed it's in the DIY list as well. Is this the only way though? I just installed a FMIC and want to test the clamps and couplers I just installed.

Sniz · 04-12-2011, 09:21 AM

pretty much......you cant easily get to any connections any farther upstream than that location.

Rob@RBTurbo · 04-12-2011, 09:35 AM

Can you link the DIY I'd like to take a look as well..

Zasquatch · 04-12-2011, 09:39 AM

http://www.e90post.com/forums/showthread.php?t=193077

Rob@RBTurbo · 04-12-2011, 12:00 PM

I'd be interested in seeing the low pressure side PCV check valves output as well in form of a leak. This would be blowby past the rings or potentially a leak in the high pressure side PCV check valve which is no good. Pressurizing to say 20psi, locking pressure in by turning off a ball valve... And timing the leakdown to say 10psi is also a good way to determine how sealed off the induction is or isn't.

Sniz · 04-12-2011, 12:20 PM

Quote:

Originally Posted by RobBeck

I'd be interested in seeing the low pressure side PCV check valves output as well in form of a leak. This would be blowby past the rings or potentially a leak in the high pressure side PCV check valve which is no good. Pressurizing to say 20psi, locking pressure in by turning off a ball valve... And timing the leakdown to say 10psi is also a good way to determine how sealed off the induction is or isn't.

based on what? What time are you looking for? I dont remember exactly how long it took to do that but it was not that long.

Rob@RBTurbo · 04-12-2011, 12:32 PM

Thats the point. The more time the better. I've had inductions sealed so well that it would take minutes to drop that. Some standardizations for testing would need developed and from there baselines or aspirations could be drawn. It would also be interesting to figure out exactly from that what or where the DMEs trigger falls into that range.

Rob@RBTurbo · 04-12-2011, 12:35 PM

Also if you didn't use a ball valve to lock in the pressure it will affect your results from a leakdown negatively. I plan on doing this soon, and I want to focus on that high pressure side PCV check valve, I'm skeptical that it's functioning properly in all cases.

Andrew@LutzPerformance · 04-12-2011, 01:46 PM

Smoke testing is the best method to find leaks, any forced induction shop should carry one, as we do.

If you have any questions feel free to email/PM me at anytime!

Jeff@TopGearSolutions · 04-12-2011, 01:47 PM

Smoke test dont pressurize the system to ~20 PSI, where fittings flex and move. Thats the only downside to smoke tests.

04-12-2011, 08:08 AM	#1
Zasquatch Captain 36 Rep 708 Posts Drives: '07 BMW 335i Join Date: Sep 2010 Location: CT iTrader: (15) Garage List 2007 BMW 335i [0.00]	Proper Boost Leak Testing Method? Hey guys, I know this has probably been discussed before my time, but what is the proper way to test for boost leaks on the N54? I know on other cars it's as simple as hooking up a PVC end cap directly to the turbo inlet/outlet and pressurizing the system to 20 psi. Our cars are not that simple, and getting to the turbos is a real PITA... I was thinking of plugging one intake pipe and pressurizing the system through the other, but those intake pipes aren't designed for boost... The other option is getting to the hot side of the intercooler and pressurizing from there... but that is one of the connections I want to test for leaks. Anyone have a good method?
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04-12-2011, 08:47 AM	#2
Sniz Lieutenant General 659 Rep 10,587 Posts Drives: e92 335 - gone // e36 M3 turbo Join Date: Mar 2007 Location: Ellicott City, MD iTrader: (1)	I did a DIY on this years ago if you can find it. basically you want to pressurize from the hot side of the intercooler. __________________
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04-12-2011, 09:21 AM	#4
Sniz Lieutenant General 659 Rep 10,587 Posts Drives: e92 335 - gone // e36 M3 turbo Join Date: Mar 2007 Location: Ellicott City, MD iTrader: (1)	pretty much......you cant easily get to any connections any farther upstream than that location. __________________
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04-12-2011, 09:35 AM	#5
Rob@RBTurbo Lieutenant Colonel 387 Rep 1,571 Posts Drives: '08 335I AT, '14 M6 DCT Join Date: Jan 2008 Location: St. Louis, MO iTrader: (5)	Can you link the DIY I'd like to take a look as well..
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04-12-2011, 09:39 AM	#6
Zasquatch Captain 36 Rep 708 Posts Drives: '07 BMW 335i Join Date: Sep 2010 Location: CT iTrader: (15) Garage List 2007 BMW 335i [0.00]	http://www.e90post.com/forums/showthread.php?t=193077
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04-12-2011, 12:00 PM	#7
Rob@RBTurbo Lieutenant Colonel 387 Rep 1,571 Posts Drives: '08 335I AT, '14 M6 DCT Join Date: Jan 2008 Location: St. Louis, MO iTrader: (5)	I'd be interested in seeing the low pressure side PCV check valves output as well in form of a leak. This would be blowby past the rings or potentially a leak in the high pressure side PCV check valve which is no good. Pressurizing to say 20psi, locking pressure in by turning off a ball valve... And timing the leakdown to say 10psi is also a good way to determine how sealed off the induction is or isn't.
	Appreciate 0 Quote

04-12-2011, 12:32 PM	#9
Rob@RBTurbo Lieutenant Colonel 387 Rep 1,571 Posts Drives: '08 335I AT, '14 M6 DCT Join Date: Jan 2008 Location: St. Louis, MO iTrader: (5)	Thats the point. The more time the better. I've had inductions sealed so well that it would take minutes to drop that. Some standardizations for testing would need developed and from there baselines or aspirations could be drawn. It would also be interesting to figure out exactly from that what or where the DMEs trigger falls into that range.
	Appreciate 0 Quote

04-12-2011, 12:35 PM	#10
Rob@RBTurbo Lieutenant Colonel 387 Rep 1,571 Posts Drives: '08 335I AT, '14 M6 DCT Join Date: Jan 2008 Location: St. Louis, MO iTrader: (5)	Also if you didn't use a ball valve to lock in the pressure it will affect your results from a leakdown negatively. I plan on doing this soon, and I want to focus on that high pressure side PCV check valve, I'm skeptical that it's functioning properly in all cases.
	Appreciate 0 Quote

04-12-2011, 01:46 PM	#11
Andrew@LutzPerformance 60 Rep 970 Posts Drives: 1995 M3 GT35R Join Date: Dec 2008 Location: 6333 N Dale Mabry Hwy Tampa, FL iTrader: (0)	Smoke testing is the best method to find leaks, any forced induction shop should carry one, as we do. If you have any questions feel free to email/PM me at anytime!
	Appreciate 0 Quote

04-12-2011, 01:47 PM	#12
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	Smoke test dont pressurize the system to ~20 PSI, where fittings flex and move. Thats the only downside to smoke tests.
	Appreciate 0 Quote