Green arrow is where it goes, it's like a little sleeve that pulls out of that white junction thing

 

So that is a clip for the fuel pressure regulator?

Ed

 

Look at the vacuum pump at idle video above. The clip locks the connector which joins the engine driven vacuum pump to the hose that runs under the car that ultimately connects to the brake booster on the firewall..

 

Does anyone know how the vacuum pump works? Where is it is it actually expelling air? Seeing that these cars run MAF I'm assuming this air has to be routed back to the intake tract somehow?

Is this changeover valve equivalent to the boost controller solenoid found on setup with non DME controlled boost?

 

Yes its a 3-way solenoid with one common port, but it doesn't control boost here ...

air ends up in the oil tank, floats to the top then into either the plenum via a check valve or to the driver side turbo inlet, this is why oil overfills are catastrophic...

did you fix the problem with your car yet?

 

Yeah I fixed the big leak that was occurring by not having that clip on that junction between brake booster tube and vacuum pump. I have been looking through Cayenne and Panamera forums and they to have a vacuum pump...although not tandem. It’s a stand-alone pump driven off passenger side camshafts. It is a wear item though and fails at times, so I’m just wondering if ours gets to an end of life as well. My car is up to 98k miles. Just wondering how or why it fails and if it’s possible on our cars.