Identify this small hose under AOS on '00 2.7L - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hi all, In the middle of an AOS replacement, and I just got the old one out. While inspecting things "while I'm in there", I came across this 4-way hose connector, and on one of the outputs of it, appears I have about a 2" little plastic line that just.. doesn't connect to anything. This seems odd to me. I can't tell if it's cut or anything. In the image attached, I've rotated it up a bit to get a better pic, but when I found it, it was laying flat over that big hose underneath it. Is this supposed to connect to something? And if so, since mine is too short to actually do that, is there a part number or name for this hose? This is on a '00 2.7L with Tiptronic transmission. Thanks in advance! Steve

Those are vacuum lines. So that line is supposed to be connected to something There should be a sticker on the inside of your trunk lid showing the vacuum hose lay out.

There's some good info about the vacuum hoses here: https://986forum.com/forums/performance-technical-chat/62979-vacuum-confusion-solved.html

I get more confused the more I read lol... I found the image below: http://986forum.com/forums/uploads02/Pic071473129781.jpg While waiting for responses to the thread, I took the passenger side intake "boot" thing out. Under it, on passenger side, I saw what appears to be "H" in that image, but there's nothing connected to the black side of it! EDIT: some more googling. seems that black and white valve thing connects directly to the intake boot. Maybe it fell out when I removed that tube from the intake. So now just trying to see where the other end of that 4-way connector hose goes (preferably without removing manifold lol) Getting a bit.. overwhelmed now... supposed to be a quick AOS swap... now this. Note there's no codes thrown related to SAI or anything. Only 1128 and 1130 when the AOS went. I can't even "trace" where that 2" line would go to since it's not connected to anything. I REALLY don't want to remove the passenger side intake. Is there something under it though that this connects to?

The Piece of hose coming out of the four way connector goes to one side of the black and white valve (H in the picture) the other side of the valve connects to the intake tube. The valve is a one way valve so you have to connect it correctly.

Yep - got that one plugged back in to the plenum when I put it all back together. The one from the original picture.. I uhhh.. just left it like I found it for now. I'm sure it goes somewhere... somewhere I can't see or feel without removing half the engine, so I put it back on the list of things to do. Got the new AOS in and everything without too much trouble.

You will have to trace out the vacuum hoses to see what is what. But if you have the one way valve reconnected. Then that broken bit of hose in your first picture goes to the change over valve for the SAI or it goes to a change over valve for your resonance flapper in the intake plenum. Either way if you leave it disconnected your creating a vacuum leak in the system. So things are not going to work properly with it disconnected.

I just redid the vacuum lines on my 2000 S so this is still fresh in my memory. Your diagram in post #4 looks correct for our year. I did notice from reading on this subject that there are differences between engines in that sometimes there is a 4 way connector and sometimes two 3 way connectors but the components are the same and they are all connected one way or another. Looking at your original photo obviously the right branch goes to the vacuum canister, the left one goes to J for the flapper valve and I assume that the top one is the line that you traced back to H and then to the plenum... so the final branch should go to E which is (in your photo) behind the vacuum canister. It is the hardest one to get to. You can get to it by removing the alternator or the plenum (I would guess, my engine was out so it was a lot easier). My suggestion is that since you will have to be digging around in there that you renew the vacuum lines and verify the vacuum canister. The stub of vacuum line looks too short the be connected to the change-over valve, I would guess that it is broken the same as mine was, the original materiel gets brittle with time. My vacuum canister was leaking as was the canister on the failed engine that I have laying around, so chances that yours is leaking are pretty good. My experience is described in post #49 of this thread: http://986forum.com/forums/boxster-general-discussions/82558-bought-2000-boxster-s-project-3.html This video may help you... https://www.youtube.com/watch?v=7OLakpX6Yj8