XR4Tim

The only spec I've found is that the pump delivery rate should be 260cm/revolution. I would guess that that means cubic centimeters, which is a volume measurement. I don't know how that would help you, but I will say that I've seen the mechanical vacuum pump fail before on a 957 S.

adrian1

1.) When I put smoke to vacuum supply doing to that pump I have smoke come out of the oil cap when I open. Normal?

2.) What powers the Vacuum Pump?

Thanks for all the help so far!

XR4Tim

1. That may be normal. I believe it vents to the crankcase.
2. It is driven mechanically by the bank one intake camshaft.

adrian1

Thanks! Going to keep trying might just change the pump and see what happens.

mramadhani

Did you ever resolve this issue? I have the same CODE p0455 and have replaced, Fuel cap, Purge Valve, Canister and Leak detection Pump to no success. Smoke tested and no leaks. Hoping you might have an answer.
2008 Cayenne Turbo

mramadhani

Hopefully this helps someone else out there. Dealership replaced vacuum pump. Said when tested side by side with a new pump, mine was half the pressure. CEL gone and so far so good.

Sniffer

Thanks for taking the time to update, like you say it`ll hopefully help someone with the same issue in the future