Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

vacuum line routing


Recommended Posts

Its hard to say without a picture but there are pretty much two of the electrical vacuum switches on the drivers side of the engine. The one thats underneath the intake, buried from plain site is for the secondary air valve. There is also a electrical vacuum switch that is right above the alternator and this is for the resonance flap located in the back of the two intake pipes. If I remember right there is a vacuum "T" right above the alternator that comes from the intake boot that supplies vacuum to both the secondary air and resonance flap switches.

Edited by PTEC
Link to comment
Share on other sites

Its hard to say without a picture but there are pretty much two of the electrical vacuum switches on the drivers side of the engine. The one thats underneath the intake, buried from plain site is for the secondary air valve. There is also a electrical vacuum switch that is right above the alternator and this is for the resonance flap located in the back of the two intake pipes. If I remember right there is a vacuum "T" right above the alternator that comes from the intake boot that supplies vacuum to both the secondary air and resonance flap switches.

so that vacuum switch activated the resonance flap on the intake?

Link to comment
Share on other sites

Its hard to say without a picture but there are pretty much two of the electrical vacuum switches on the drivers side of the engine. The one thats underneath the intake, buried from plain site is for the secondary air valve. There is also a electrical vacuum switch that is right above the alternator and this is for the resonance flap located in the back of the two intake pipes. If I remember right there is a vacuum "T" right above the alternator that comes from the intake boot that supplies vacuum to both the secondary air and resonance flap switches.

so that vacuum switch activated the resonance flap on the intake?

That looks like the switchover valve for the intake flap. You should have two hard vacuum lines connected to it, one from the vacuum tank buried behind and under the intake, and the other line goes to the flap. The lines are extremely brittle on old cars. I had to change mine as they just desintegrated when I tried to handle them.

Link to comment
Share on other sites

  • 1 year later...

Can you please help me with how to do this. I was changing my Alternator and broke the thin hard skinny tube that came from the Vacuum Swithchover valve that literally sits on top of the alternator. IT runs from the valve to the top of the motor somewhere. I am trying to figure out where this goes??? Any help would be greatly appreciated. Part Number or numbers also since I broke it in half and need to replace it. Since you replaced all of them the part numbers would be great. I have a 2000 996 cab 6 speed

Link to comment
Share on other sites

There are two hoses from that change over valve. One goes into a fitting that connects to the vacuum reservior (below the drivers side intake plenum behind the alternator). The other hose from that valve goes into a small tube that enters the resonance flap which is in the intake cross over tube behind the T plenum/Throttle body.

You can reach behind to the resonsance flap if you remove the throttle body and t-plenum. That might also allow access to get to the line that goes to the vacuum reservior, but you may also have to remove the alternator to gain access.

I replied in your other post about the part number for the tube.

Tubing. 00004320501, sold by the meter.

Edited by logray
Link to comment
Share on other sites

Thanks so much...Is there a diagram of the tube routing and the locations for the connections. I am not experienced with what part is what part based on the names you used? Sorry for the ignorance on the part names. I have been a DIY mechanic for a while but I do better with diagrams. Any help would be greatly appreciated.

Tim

Link to comment
Share on other sites

What is the DTC?

Check out this web page for how to access that area and for more info about those tubes, remove the throttle body, t-plenum/etc.:

http://p-car.com/996/diy/sai/mainpage.html

In the link below, one of the tubes you are talking about is #19, which goes into 21 which then goes into the resonance flap:

http://www.autoatlanta.com/porsche-parts/996-99-05/107-10.php

The other tube from that change over valve on that goes to the vacuum reserver is #29 or 30 in the below link. I'm pretty sure it's # 29, but it would be obvious which one it is once you have access to that area.

http://www.autoatlanta.com/porsche-parts/996-99-05/108-05.php

Still, I'm going based off some assumptions. Without seeing a picture of what you are describing, I'm just making assumptions. Since we don't have the trouble codes I'm guessing based on your description and work you were doing.

  • Upvote 1
Link to comment
Share on other sites

This picture I found in your tutorial shows the location of the tube. There are three tubes on this Grey Switch. 2 are very obvious. There is another tube connected to this switch. It isnt shown because it is underneath of the switch and heads directly to the front of the car. That is the tube I broke in half. Consequently the tube also came disconnected from the top of the motor. It is a very stiff plastic tube. Does this help?

DSC02180.jpg

Link to comment
Share on other sites

OK..just finally got to the car. The tube that is broken is the one shown in your picture. It is the first one on the lower left that is circled and looks like a U or a macaroni. Where does this go and is there a part number for it? Will your tutorial work for me to access the location it needs to be?

Link to comment
Share on other sites

Yes that tube goes to the resonance flap. It's probably a really long tube right? That's the one that goes to the rear of the engine (front of car).

From my above post:

"In the diagram link below, the tubes you are talking about is #19, which goes into #21 (another hose) which then goes into the resonance flap:

http://www.autoatlan...9-05/107-10.php"

Yes the DIY link I posted has the procedure you need to remove the throttle body and t-plenum so you can reach behind the rear intake crossover and reconnect a new tube from the resonance flap to the change over valve in the position you indicate (hose/tube p/n 00004320501 qty 1) You might need a extendable mirror to see it.

  • Upvote 7
Link to comment
Share on other sites

  • 1 year later...

Okay guys, mostly related question so I thought I would just add to the post.

I read through the P-car write up, then found this post on rennlist

480436d1286858580-aos-replacement-and-pad-change-out-diagram.jpg

So I found that my resonance flap was not connected to anything, and the diverter valve for the resonance flap had both lines plumbed into #19.

I reconnected the lines for above valve into what I believe to be the correct orientation. BUT when I did that I was left with one of the branches of #19 not connected to anything. Upon further inspection I found a 2 wire plug lying in the same area as these vacuum lines. The plug is on wires that appear to run between the furthest two intake runners.

So my actual question is: Where does #18 mount to and what does it connect to? I am trying to determine if it is even on the engine and this particular diagram doesn't help much.

Thoughts?

Link to comment
Share on other sites

  • 3 weeks later...

So my actual question is: Where does #18 mount to and what does it connect to? I am trying to determine if it is even on the engine and this particular diagram doesn't help much.

I suppose I should clarify- the LOWER #18. what does it control and where else is it plumbed into?

Link to comment
Share on other sites

  • 1 year later...

I know that this is an older thread but it saved me today! I replaced the alternator and through the process, disconnected #19 vacuum line. I looked everywhere for a loose/open connection but could not find it.

 

Then I read this post and found #20 vacuum line in about 10 seconds up behind the rear intake where the resonance flapper is located. Re-inserted #19 into #21 and now I can proceed with re-installing the throttle body.

 

Thanks!

Edited by thstone
Link to comment
Share on other sites

  • 6 years later...
3 hours ago, DBJoe996 said:

In case someone searches for vacuum line routing in the future

 

vac.jpg

Appreciate that!  I have the stuff on order from pelican and will be hitting it this weekend when I put the new alternator in.  This will absolutely be helpful.  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.