Oil Leak Over Intake Pipes

[Reza]

Hello Everybody:

This is about my Cayenne S 2004 with 65K mile.

Last night I found a thin layer of oil spread over the driver side of the engine next to the black intake pipes. I then found the Throttle Vent (pipe) in front of the engine (under the plastic cover written on it: "V8 4.5") is broken and the fluid seeps out of it over the engine head, from the very front of engine all the way to the end along side with injectors. The Vent connects Point A to B in the picture.

I would like to learn what this pipe carry because the yellowish fluid seems to be mixture of oil and water that is changed to yellowish color....

I am confused as why a vent from Throttle should have oil and water in it... the fluid in the pipe was yellowish, however the oil coating on the side of engine along the Intake pipes was clear oil, dark color. I would be highly appreciated if someone could explain what it is?

Thank you.

[RFM]

The pipe is a part of the crankcase ventilation system, there will always be an oil residue present by precipitating oil vapors. The yellowish creamy fluid is a mix of these oil residue and water vapour from the combustion which precipitates as water drops on the coldest parts of the engine, remember that a cold engine get soaking wet inside until fully warmed up ( approx. 10 a 15 Km normal driving). This is therefore a normal phenomenon.

[Reza]

Thanks for sharing the knowledge.

So the flow direction (as per the photo) would be from point B to point A and this residual fluid will be send over the pistons and burned in the cylinders, correct?

The pipe was broken and I glued it in 2 positions (maybe visible in the photo) for the time being until I receive my order. It was $130.

I used kind of EXTREME GLUES that can tolerate temperatures ranging -54F to 120F. I am wondering if the glue will last? I do not think there is any pressure or that much of current or fluid passing through this pipe to possibly brakes it? Do you agree?

[RFM]

More or less, point B on the pic is the Cayenne AOS, replacing the tube is the proper method, repair with glue is looking for trouble IMHO.