Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E36 (1991 - 1999)

E36 (1991 - 1999)
The E36 chassis 3-Series BMW was a huge hit among driving enthusiasts from the first moment the car hit the pavement. The E36 won numerous awards over the years it was produced and is still a favorite of many BMW enthusiasts to this day! -- View the E36 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 10-02-2012, 04:18 PM
dc_wright's Avatar
dc_wright dc_wright is offline
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,014
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
Anyone Had Power Brake Booster With a Vacuum Leak?

I think I may have a vacuum leak in my brake booster. I have a turbo like whistle I can hear better from inside the car than from the engine compartment, I have power boost to the brakes but the effort feels higher than it should (definitely higher than my E46 by comparison), and when I hook my vacuum gauge directly to the manifold I get 19", but when I tee in with the brake booster connected in I get 17"-18". Also when I apply the brakes with the vacuum gauge teed in I get a vacuum drop (expected) but it takes several seconds to build back up to 17".
Anybody had this before?
I've sprayed brake cleaner all around the intake manifold and the associated hose connections without any vacuum leak associated signs, but the "turbo whistle" persists.
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)

Last edited by dc_wright; 10-02-2012 at 04:20 PM.
Reply With Quote
Advertisement
  #2  
Old 10-02-2012, 05:02 PM
Echo46 Echo46 is offline
Officially Welcomed to the 'Fest
Location: Long Island, New York
 
Join Date: Jul 2008
Posts: 223
Mein Auto: 2006ZCP M3and 1999 M3vert
Have you inspected the intake manifold adjuster-DISA Valve- for leak and/or functionality?
Reply With Quote
  #3  
Old 10-02-2012, 05:42 PM
drivinfaster's Avatar
drivinfaster drivinfaster is offline
bimmerfest Supporting Member
Location: in the sticks you piney
 
Join Date: Nov 2007
Posts: 10,733
Mein Auto: rescued bmw's
disconnect the vac feed to the booster, block it off, and see if vac increases. if it does, then suspect a leak.


if you have a vac pump, you could also use an adapter to fit the inlet, and then apply vacuum. if it holds, then no leak. if it does not hold, suspect a leak.



df
__________________
Reply With Quote
  #4  
Old 10-02-2012, 05:44 PM
dc_wright's Avatar
dc_wright dc_wright is offline
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,014
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
I would if I had one. It's a 328, not a 318.
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)
Reply With Quote
  #5  
Old 10-02-2012, 05:46 PM
drivinfaster's Avatar
drivinfaster drivinfaster is offline
bimmerfest Supporting Member
Location: in the sticks you piney
 
Join Date: Nov 2007
Posts: 10,733
Mein Auto: rescued bmw's
Quote:
Originally Posted by dc_wright View Post
I would if I had one. It's a 328, not a 318.



df
__________________
Reply With Quote
  #6  
Old 10-02-2012, 05:51 PM
ZeGerman's Avatar
ZeGerman ZeGerman is online now
Warm Leatherette
Location: Seattle, WA
 
Join Date: Mar 2009
Posts: 18,850
Mein Auto: 1998 BMW 328is
^I thought only 318s had DISA valves, too.
__________________

1998 BMW 328is
1966 Pontiac GTO
2007 Subaru Impreza 2.5i 5-door
View my photos: Caught in the Wild
For sale: E30/E36 front sway links
For sale: OEM E36 328 catback
Reply With Quote
  #7  
Old 10-02-2012, 06:00 PM
dc_wright's Avatar
dc_wright dc_wright is offline
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,014
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
Quote:
Originally Posted by drivinfaster View Post
disconnect the vac feed to the booster, block it off, and see if vac increases. if it does, then suspect a leak.


if you have a vac pump, you could also use an adapter to fit the inlet, and then apply vacuum. if it holds, then no leak. if it does not hold, suspect a leak.



df
I probably wasn't clear in my OP. When I disconnect the vac feed to the booster I get 19". When I tee into the vac feed line so that it's connected to the manifold and the booster is when I get 17"-18".
I've got a mighty Vac and when I connect it to the booster hose I don't think I've been able to get the one way valve to open so I think I've only been testing the hose......I may just have to pump the crap out of it for a while to verify I've got it really evacuated.
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)
Reply With Quote
  #8  
Old 10-02-2012, 06:12 PM
drivinfaster's Avatar
drivinfaster drivinfaster is offline
bimmerfest Supporting Member
Location: in the sticks you piney
 
Join Date: Nov 2007
Posts: 10,733
Mein Auto: rescued bmw's
a smoke machine would also work, but not many of us have those...

if it leaks, it's visible.



df
__________________
Reply With Quote
  #9  
Old 10-02-2012, 06:31 PM
dc_wright's Avatar
dc_wright dc_wright is offline
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,014
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
I think it may be the grommet where the one way valve plugs into the vac booster. When I tried pumping it down when the hose was connected to it I couldn't get it to hold anything. I popped the one way valve out along with the hose and pumped it down to 25" no problem. I plugged it back in and with a crap load of pumping with the MightVac it pumped down to 20" and seems to be holding. I'm going to let it sit there for a while and see if it held.
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)
Reply With Quote
  #10  
Old 10-02-2012, 06:38 PM
drivinfaster's Avatar
drivinfaster drivinfaster is offline
bimmerfest Supporting Member
Location: in the sticks you piney
 
Join Date: Nov 2007
Posts: 10,733
Mein Auto: rescued bmw's
some rtv around the grommet may help. at least until a new one can be delivered.



df
__________________
Reply With Quote
  #11  
Old 10-02-2012, 07:05 PM
dc_wright's Avatar
dc_wright dc_wright is offline
bimmerfest Supporting Member
Location: Orlando, Florida
 
Join Date: Nov 2007
Posts: 7,014
Send a message via ICQ to dc_wright
Mein Auto: '96 328iC, '04 325Ci
Held for 20 minutes no problem. I'm going to order the grommet, the one way valve, and the hose and see if that does the trick.
__________________
2006 Z4 3.0si Sport Package (But I'll still hang with my "homies" in the E36 forum)
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E36 (1991 - 1999)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 03:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms