Boost leak from divert valve seal leak

Ghoti · 02-11-2012, 11:48 PM

Something to keep in mind when you think you have boost leak...

I had recently installed a FMIC, following which I had significant boost leak (boost max'd at ~10 psi, but should have been around 18-19 with the COBB). After the shop checked the clamps associated with the FMIC a couple times and performed smoke tests, they finally traced the problem to leaking diverter valve seals.

After removing the diverter valves and cleaning the seals, everything works great. Max boost is now 19+ psi.

nitehawk · 02-12-2012, 12:24 AM

Quote:

Originally Posted by Ghoti

Something to keep in mind when you think you have boost leak...

I had recently installed a FMIC, following which I had significant boost leak (boost max'd at ~10 psi, but should have been around 18-19 with the COBB). After the shop checked the clamps associated with the FMIC a couple times and performed smoke tests, they finally traced the problem to leaking diverter valve seals.

After removing the diverter valves and cleaning the seals, everything works great. Max boost is now 19+ psi.

Interesting. So you didn't actually need to replace anything. Just clean and reinstall?

I'm also on factory diverter valves without issues on Cobb S2+ Agg

Ghoti · 02-12-2012, 01:02 AM

Quote:

Originally Posted by nitehawk

Interesting. So you didn't actually need to replace anything. Just clean and reinstall?

I'm also on factory diverter valves without issues on Cobb S2+ Agg

Yes, just clean and reinstall. It took the tech about an hour to diagnose and complete.

Bagelfast · 02-12-2012, 11:28 AM

Interesting, what exactly did they clean inside of the diverter valves? or just the seals and seal area themselves?

Ghoti · 02-13-2012, 11:18 PM

Quote:

Originally Posted by 1LUMI335

Interesting, what exactly did they clean inside of the diverter valves? or just the seals and seal area themselves?

My understanding is they just cleaned the seals and the seal area. I think the tech mentioned that the valves weren't fully seating themselves due to a buildup of something.

BMWsky · 02-14-2012, 06:53 AM

I'd keep an eye on them as some have the propensity to pop off more than others.

skim7x · 02-14-2012, 07:38 AM

Yeah I'm on cobb stg2+fmic with stock diverter valves and charge pipe without any problems...

02-11-2012, 11:48 PM	#1
Ghoti Second Lieutenant 9 Rep 289 Posts Drives: 335i Join Date: Aug 2011 Location: Toronto iTrader: (0)	Boost leak from divert valve seal leak Something to keep in mind when you think you have boost leak... I had recently installed a FMIC, following which I had significant boost leak (boost max'd at ~10 psi, but should have been around 18-19 with the COBB). After the shop checked the clamps associated with the FMIC a couple times and performed smoke tests, they finally traced the problem to leaking diverter valve seals. After removing the diverter valves and cleaning the seals, everything works great. Max boost is now 19+ psi. __________________ SG e92 335i 6MT / Pure Stg2 DD / JB4 + MHD BEF / ETS FMIC / Dinan CAI / AR DPs / Stage 2 LPFP / Spec 3+ / Spec SMFW / MFactory LSD / KW V2 SCs / Vibrant 1792s e36 M3 ... gone but not forgotten
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02-12-2012, 11:28 AM	#4
Bagelfast Lieutenant Colonel 125 Rep 1,546 Posts Drives: BMW Join Date: Sep 2008 Location: USA iTrader: (0)	Interesting, what exactly did they clean inside of the diverter valves? or just the seals and seal area themselves?
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02-14-2012, 06:53 AM	#6
BMWsky Major 24 Rep 1,244 Posts Drives: 335i Join Date: Dec 2010 Location: Webster NY iTrader: (1)	I'd keep an eye on them as some have the propensity to pop off more than others.
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02-14-2012, 07:38 AM	#7
skim7x Colonel 208 Rep 2,558 Posts Drives: 335i, C63 AMG Join Date: Sep 2006 Location: USA iTrader: (4) Garage List 2007 335i [10.00]	Yeah I'm on cobb stg2+fmic with stock diverter valves and charge pipe without any problems... __________________ '07 Space Gray 335i coupe - R.I.P. COBB ProTuned \| AMS \| CP-e \| BMS \| Quaife
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