My car is a 1990 Turbo II and I honestly do not know if the vacuum harness is original or not, the last owner wasn't very smart and so I wouldn't doubt if something is totally wrong. I have replaced so many vacuum lines that weren't even attached or blocked off, just sucking air....

In the first picture the circled area is near the neck of the oil fill and I can't figure out what goes into it...idk if it is coolant return or not. Any one know?

In the second picture, the red one is similar to the first picture and IDK if they are possibly the 2 that need to go together or not. The two blue circled ones look to me like vacuum nipples and do they have specific spots or are they suppose to be linked together?

In the third picture, the place where the vacuum solenoid valves are is shown. There are 3 of the solenoids there and that is what is shown in my manuals but for some reason their is a 4th spot shown in the red square. I have a spare solenoid that has the orange/yellow sticker on top like the one that is right on the rightside edge of the square which is what those hoses that are circled would go to. Those circled hoses have possible connections to the hard vac lines but those lines don't run to anything that is shown in my manual and I have no clue if maybe this vac line system is from a different model and is being used on my s5 or not. anyone have any input? Thanks for reading and looking

 

i think the first one goes to a line on the firewall and then to the charcoal canister.

second pic, i think the big one on the bottom is the brake booster. the others i'd have to get the book out and start going point to point.

third pic i think is the boost control solenoid hoses, or one is and the other is the other side of the PCV?

 

In regards to picture 2, my book shows the duty solenoid sits on the bracket attached to the oil fill neck but to be honest now that I think about it those lines are for the solenoid...for some reason I didn't run my hose through them like an idiot.