pageysparts

Hi All,
I have various symptons pointing to a blocked crankcase breather (PCV?)
and/or EGR Valve. Symptons are white/Grey smoke when waiting in traffic when engine is at running temp not cold. Runs/drives perfectly cold or hot. Also another problem which I'm told could also be cause by build up of pressure is at running temp if I stop for a short time such as refueling it struggles to start but always cold start or left for a period of time starts with no effort, I changed battery just for the sake of the obvious possibility of a faulty battery.
My Questions:
1. Is the "Oil Separator", next to the oil filter housing, the same as PCV/Crankcase Breather?
2. Does anyone know the location on the engine if not?
3. Does anyone know the parts numbers for the breather valve and hoses??
4. Am I going in the right direction with these symptons??
Regards Neil

Panelhead

Pull the oil fill cap with the vehicle running. That will tell if it is completely toast. The engine should pull a vacuum.
But I just changed mine at 10 years. The replacement is the Vaico brand at Partsgeek. It is 30.00.
The crankcase vent valve is a little difficult to get to. The change is easy.
This and the brake light switch are parts that are best changed before failure. They can cause intermittent issues that are hard to diagnose.

MP4.2+6.0

Adding on, the oil separator is different than PCV. PCV is the big plastic valve several inches across--ridiculous German overengineerng compared to common American or Japanese designs. The oil separator is a screen/baffle sort of thing down under a cover in the "V" of the motor if it remains the same as my 2000 4.2. You can't see it because it is under the intake manifold. A hose comes up from it that meets the PCV valve at its base.

Also watch your coolant be sure you aren't describing a coolant issue--head gasket, etc. If it is gray toward black, it's oil, but gray toward white is water/coolant. If worse on a cold day and not just when starting, a big flag.

Mike141

What year is your car? This matters because the D3s had 2 different engines. I recently replaced my oil separator which is located just behind oil filter housing on the FSI engine. Mine froze over the harsh winter causing oil leaks.

Jack88

Add a few to the list if he's not in the U.S. Year and engine are necessary for accurate information.

Sci-fi_Wasabi

Below is a thread i started. It has pics of the oil separator and a pic of the part number for the D3 4.2L engine in the USA: 079 104 464 F. i think it was around 120$ from the dealer.

https://www.audiworld.com/forums/a8-...-leak-2869690/

Mike141

I just replaced mine not too long ago on my 2007 4.2L. 079103464F which cost me just under $250 from Jim Ellis Audi....my local dealer was in the area of $320 for this part.