Vacuum questions.

Scrippy · 10-23-2014, 06:18 PM

Guys,

So I've replaced the following but I still see vacuum pressure dropping in front of my eyes when I turn engine off. My gauge is tapped in to the hose that leads to the exhaust flap. I removed the line going to exhaust and plugged in my meter. Here's what I've replaced.
1-both boost solenoids
2-all vacuum hose from hard pipe to SOLENOIDS and wastegates.
3-grommet in brake booster
4-hard line with valve that goes into the grommet.
5-all the rubber rings in hard pipe connections.
So at idle I'm at 25-26"Hg but after I turn car off it just drops and drops. After 3 minutes I'm at 15"Hg. Any ideas or does the system not hold all vacuum reliably with engine off.

Ingeniator · 10-23-2014, 06:47 PM

Check your brake booster with a vacuum pump. If it holds and doesn't lose vacuum it could be a wg actuator. I'm not 100% sure it should maintain vacuum but I would think it would.

Scrippy · 10-23-2014, 07:05 PM

Quote:

Originally Posted by Ingeniator

Check your brake booster with a vacuum pump. If it holds and doesn't lose vacuum it could be a wg actuator. I'm not 100% sure it should maintain vacuum but I would think it would.

I actually replaced my turbos and actuators too. Forgot to list that.

Scrippy · 10-23-2014, 09:49 PM

I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though.

Ingeniator · 10-23-2014, 10:11 PM

Quote:

Originally Posted by Scrippy

I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though.

Brake booster diaphragm?

Scrippy · 10-23-2014, 10:19 PM

Quote:

Originally Posted by Ingeniator

Quote:

Originally Posted by Scrippy

I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though.

Brake booster diaphragm?

Good lead! Thanx!

Dmacc · 10-23-2014, 10:49 PM

Quote:

Originally Posted by Scrippy

Quote:

Originally Posted by Ingeniator

Quote:

Originally Posted by Scrippy

I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though.

Brake booster diaphragm?

Good lead! Thanx!

Please post your findings!

Scrippy · 10-23-2014, 11:07 PM

Quote:

Originally Posted by Dmacc

Quote:

Originally Posted by Scrippy

Quote:

Originally Posted by Ingeniator

Quote:

Originally Posted by Scrippy

I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though.

Brake booster diaphragm?

Good lead! Thanx!

Please post your findings!

Will do, check back tomorrow and I'll have found out.

Dmacc · 01-19-2015, 06:15 PM

Quote:

Originally Posted by Scrippy

Will do, check back tomorrow and I'll have found out.

Did you ever find a solution to this issue?

Scrippy · 01-20-2015, 10:56 AM

Quote:

Originally Posted by Dmacc

Quote:

Originally Posted by Scrippy

Will do, check back tomorrow and I'll have found out.

Did you ever find a solution to this issue?

So I replaced the brake (1)booster grommet and the (2)pipping leading into it and to the vacuum pump bellow the airbox. This definitely helped my vacuum leak. It's appears to be gone which is cutting down my wastegate rattle. My turbos were rebuilt when I did them but not the wastegate pivot. So there is play which leads to rattle. Doing this grommet and associated pipe gave me a healthier vacuum system which eliminates all but 20% of the noise. All and all these two parts are relatively cheap and should be changed every 4-5 years if your asking my opinion. Engine heat kills plastic and rubber, so failure is common. The check valve in the pipe seemed to be my real issue when compared on a bench with the new part. I used a Mittyvac to test.

Dmacc · 01-20-2015, 03:13 PM

Quote:

Originally Posted by Scrippy

Quote:

Originally Posted by Dmacc

Quote:

Originally Posted by Scrippy

Will do, check back tomorrow and I'll have found out.

Did you ever find a solution to this issue?

So I replaced the brake (1)booster grommet and the (2)pipping leading into it and to the vacuum pump bellow the airbox. This definitely helped my vacuum leak. It's appears to be gone which is cutting down my wastegate rattle. My turbos were rebuilt when I did them but not the wastegate pivot. So there is play which leads to rattle. Doing this grommet and associated pipe gave me a healthier vacuum system which eliminates all but 20% of the noise. All and all these two parts are relatively cheap and should be changed every 4-5 years if your asking my opinion. Engine heat kills plastic and rubber, so failure is common. The check valve in the pipe seemed to be my real issue when compared on a bench with the new part. I used a Mittyvac to test.

Thanks for the reply, that's some good info. Do you have any spare pictures you may have taken of these parts you replaced?

Scrippy · 01-20-2015, 07:00 PM

Quote:

Originally Posted by Dmacc

Quote:

Originally Posted by Scrippy

Quote:

Originally Posted by Dmacc

Quote:

Originally Posted by Scrippy

Will do, check back tomorrow and I'll have found out.

Did you ever find a solution to this issue?

So I replaced the brake (1)booster grommet and the (2)pipping leading into it and to the vacuum pump bellow the airbox. This definitely helped my vacuum leak. It's appears to be gone which is cutting down my wastegate rattle. My turbos were rebuilt when I did them but not the wastegate pivot. So there is play which leads to rattle. Doing this grommet and associated pipe gave me a healthier vacuum system which eliminates all but 20% of the noise. All and all these two parts are relatively cheap and should be changed every 4-5 years if your asking my opinion. Engine heat kills plastic and rubber, so failure is common. The check valve in the pipe seemed to be my real issue when compared on a bench with the new part. I used a Mittyvac to test.

Thanks for the reply, that's some good info. Do you have any spare pictures you may have taken of these parts you replaced?

Parts 8,9 and 4 in the attached picture.

10-23-2014, 06:18 PM	#1
Scrippy Lord Scrip 1954 Rep 3,124 Posts Drives: 2011 M3 Coupe Join Date: Jan 2012 Location: LA,Ca iTrader: (0) Garage List [10.00] 2007 BMW 335i [10.00]	Guys, So I've replaced the following but I still see vacuum pressure dropping in front of my eyes when I turn engine off. My gauge is tapped in to the hose that leads to the exhaust flap. I removed the line going to exhaust and plugged in my meter. Here's what I've replaced. 1-both boost solenoids 2-all vacuum hose from hard pipe to SOLENOIDS and wastegates. 3-grommet in brake booster 4-hard line with valve that goes into the grommet. 5-all the rubber rings in hard pipe connections. So at idle I'm at 25-26"Hg but after I turn car off it just drops and drops. After 3 minutes I'm at 15"Hg. Any ideas or does the system not hold all vacuum reliably with engine off. Attached Images __________________
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10-23-2014, 06:47 PM	#2
Ingeniator Major 35 Rep 1,093 Posts Drives: 07 335XI(90) 09 135I(82) Join Date: Nov 2013 Location: Fort Mac, Alberta iTrader: (1)	Check your brake booster with a vacuum pump. If it holds and doesn't lose vacuum it could be a wg actuator. I'm not 100% sure it should maintain vacuum but I would think it would. __________________ 07 335XI (A008006) 6AT ~94K miles JB4 G5 ISO VSRF DP's 09 135I M (VK80379) 6MT. Race Project car. 1) Install Cobb/piggyback? and Motiv 600 Kit[HTA3076R w/ tial .82] 2) JRZ or Moton suspension. 3) Build high flow intake manifold with multi-port fuel and relocate OFH 4) Build full cage 5) Complete staged twin setup with HTA4205R [w/Tial 1.16] 6) Complete dry sump system
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10-23-2014, 09:49 PM	#4
Scrippy Lord Scrip 1954 Rep 3,124 Posts Drives: 2011 M3 Coupe Join Date: Jan 2012 Location: LA,Ca iTrader: (0) Garage List [10.00] 2007 BMW 335i [10.00]	I know it's not the actuators. I replaced them 2 months ago. I also tried removing the vac lines from the top of canisters and jumpered them together with a piece of vac line. This takes the solenoids and wastegates out of the equation. It still drops though. __________________
	Appreciate 0 Quote