MkII 996 vacuum line routing and related components
06-04-2015, 01:52 PM
#18
Drifting
Thank you Ahsai !
Ahsai, Great photo of the vacuum system. I have been bewildered by the rats nest of brittle vacuum lines .Your photo is a great help.I had been collecting every post I could find to try to piece together a full ,captioned photo of the entire vacuum system -correctly configured.
Thanks for taking the time to post this for us.
Thanks for taking the time to post this for us.
10-13-2015, 08:01 AM
#20
thanks for the breakdown, this is my next project. My cel comes on when sitting in traffic but never when i am moving so the vacuum system must be searching for something.
08-18-2016, 07:32 PM
#21
Burning Brakes
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Just wanted to say thanks for the picture!!!
I broke a vacuum line while putting my alternator back in after an oil filler tube replacement. Then managed to pull the line loose from the intake resonance flap actuator.
I knew I would figure out what I did here. Now that I know what I did time to collect parts and plan some down time.
I broke a vacuum line while putting my alternator back in after an oil filler tube replacement. Then managed to pull the line loose from the intake resonance flap actuator.
I knew I would figure out what I did here. Now that I know what I did time to collect parts and plan some down time.
09-18-2016, 06:08 PM
#22
Drifting
Ahsai, Great photo of the vacuum system. I have been bewildered by the rats nest of brittle vacuum lines .Your photo is a great help.I had been collecting every post I could find to try to piece together a full ,captioned photo of the entire vacuum system -correctly configured.
Thanks for taking the time to post this for us.
Thanks for taking the time to post this for us.
02-07-2017, 01:32 PM
#23
Drifting
Join Date: Sep 2011
Location: Ephrata, PA, USA now. Originally from the UK
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how is this possible
I'm in the process of replacing my AOS and the starter cable so I have the left intake manifold off the engine ('03 C2 coupe manual transmission). While I'm in there, I decided to refresh my vacuum system and replace all the vacuum lines, the rubber Y's and elbows, the vacuum reservoir, and the two changeover valves. All that for only $130. The stock vacuum line is available from Porsche for a few bucks per meter and you need about 1,200 mm. You can also replace them with your favorite vacuum hoses. I stay with stock lines since they hold up surprisingly well and they are light and less bulky.
Stock vacuum hose line P/n 00004320501 (1m)
I just want to document the info here hopefully helping the next guy.
Attachment 896507
My stock vacuum lines are still in very good shape as far as I can tell but the problems are all the "Y" and elbows. They are not sealing the best. Also, the vacuum reservoir is leaking slowly while tested with a hand vacuum pump. I also tested the changeover valves and they are all good.
The system is very simple. The vacuum is supplied to the one-way check valve from the intake plenum then it branches off to the vacuum reservoir and changeover valve #1, which powers the intake resonance actuator when electrical power is supplied.
The vacuum reservoir then supplies vacuum to changeover valve #2, which powers the SAI one-way check valve that opens whenever the SAI pump is running.
To check the system quickly, you can use connect a hand vacuum pump to the black/white valve and create vacuum. Then you power each changeover valve and you should hear the resonator flap rotates and the SAI valve moves as well.
To check whether the WHOLE system holds vacuum, remove the black/white valve and connect the pump there and start pumping. Vacuum level should stay once you reach some vacuum level and stop pumping.
Stock vacuum hose line P/n 00004320501 (1m)
I just want to document the info here hopefully helping the next guy.
Attachment 896507
My stock vacuum lines are still in very good shape as far as I can tell but the problems are all the "Y" and elbows. They are not sealing the best. Also, the vacuum reservoir is leaking slowly while tested with a hand vacuum pump. I also tested the changeover valves and they are all good.
The system is very simple. The vacuum is supplied to the one-way check valve from the intake plenum then it branches off to the vacuum reservoir and changeover valve #1, which powers the intake resonance actuator when electrical power is supplied.
The vacuum reservoir then supplies vacuum to changeover valve #2, which powers the SAI one-way check valve that opens whenever the SAI pump is running.
To check the system quickly, you can use connect a hand vacuum pump to the black/white valve and create vacuum. Then you power each changeover valve and you should hear the resonator flap rotates and the SAI valve moves as well.
To check whether the WHOLE system holds vacuum, remove the black/white valve and connect the pump there and start pumping. Vacuum level should stay once you reach some vacuum level and stop pumping.
02-07-2017, 01:46 PM
#24
Nordschleife Master
Thread Starter
Yes, you need to remove at least the alternator. If you need more room, you can remove the throttle body as well.
02-07-2017, 02:00 PM
#25
Drifting
Access & visibility under the inlet manifold is a problem. I have a useful, peculiar tool to help. Kobalt Snake Light 15" LED. Not the hypercoil - that is too big.
The idea is to get the brightest ,smallest LED you can .
I found one with a mirror attachment .Have not tried it.
Any tool purchase is better than removing the inlet manifold !
Let us know how it goes?
FYI I just ordered this (with 33LED lights!)for working in the same area. In theory I could use a borescope+laptop but that seems odd.
The idea is to get the brightest ,smallest LED you can .
I found one with a mirror attachment .Have not tried it.
Any tool purchase is better than removing the inlet manifold !
Let us know how it goes?
FYI I just ordered this (with 33LED lights!)for working in the same area. In theory I could use a borescope+laptop but that seems odd.
Last edited by Schnell Gelb; 02-07-2017 at 02:19 PM.
02-07-2017, 05:04 PM
#26
Rennlist Member
I accidentally knocked a vacuum line off when changing my alternator. I found it easiest to access it by removing the throttle body....and MUCH easier than removing the alternator...took me forever to wiggle the alternator out the first time, no way I was going through that again. Took 5 mins to remove the throttle body.
02-07-2017, 08:01 PM
#27
Drifting
The problem with the alternator removal is usually that pesky bushing at the back. It tends to corrode in place. If you can remember when you have the alternator out - put some grease on it.
02-09-2017, 08:14 AM
#29
Drifting
Join Date: Sep 2011
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I have had my alternator out 4 times already. Also the Throttle body and idle body to clean both and replace with new gaskets. Tricky but doable. Found a broken vacuum line and joined it making it longer with fish tank air supply line. I would like to replace all lines as Ashai did. I do have a scope with LED light and hand held monitor but the dam thing is so hard to twist to see the Y junctions and what ever else. I shall persist and do the job eventually. ASHAI I had the idle valve in my hand. Can you tell me if the idler beveled door should close completely or is it always a sixteenth of an inch open with power off. I see it open fully when I add power from plug with ignition switch in the on position.
02-09-2017, 11:37 AM
#30
I have had my alternator out 4 times already. Also the Throttle body and idle body to clean both and replace with new gaskets. Tricky but doable. Found a broken vacuum line and joined it making it longer with fish tank air supply line. I would like to replace all lines as Ashai did. I do have a scope with LED light and hand held monitor but the dam thing is so hard to twist to see the Y junctions and what ever else. I shall persist and do the job eventually. ASHAI I had the idle valve in my hand. Can you tell me if the idler beveled door should close completely or is it always a sixteenth of an inch open with power off. I see it open fully when I add power from plug with ignition switch in the on position.