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Morning guys,

I'm trying to locate the PCV valve but am having trouble finding it. All the searches online it appears to be part no. 077103245B and looks as follows:


but i can't for the life of me find this one in the engine bay. The only valve under the engine cover I can locate is the below, but this is a crankcase purge valve (part no. 06e 906 517):


So this is one for the guys who know their engines, are these two actually the same thing and the lower image is just 'our' RS4 version, or is the crankcase purge valve totally separate to the PCV valve, in which case can anyone point me to where the damn thing is?!

Thanks, Al

The OEM Part Number is: 079103464F or 079 103 464 F.

http://jhmotorsports.com/shop/catalog/o ... p-923.html

This picture is for the Q7 but same location, one would expect:

Thanks guys,

Tony, im guessing it's the 'non-return valve (crankcase breather)' bottom right in that image?

Is this an easy one to replace the PCV valve myself (as a fairly average car diy'er), or is something like this best left to the garage? Camberley Audi is my local.

RS4-AL wrote:Thanks guys,

Tony, im guessing it's the 'non-return valve (crankcase breather)' bottom right in that image?

Is this an easy one to replace the PCV valve myself (as a fairly average car diy'er), or is something like this best left to the garage? Camberley Audi is my local.

I'm not too sure tbh, need to go have a look at mine to make sure that diagram is similar enough. I do know the PCV system has a breather pipe which connects to the intake just before the throttle body (mine cracked so i had to mend it) but it was difficult to follow the pipe to see where it came from.

Tony when you take a look could you do me a quick favour?

I've read that the simplest way to diagnose a faulty PCV valve is to start up the engine then remove the oil filler cap whilst the engine is idling. If the engine suddenly bogs down and there is a strong suction of air being drawn into the oil filler then apparently that means the PCV valve has a fault. When you put the oil filler cap back on it then idles as usual.

Mine bogs down and has a lot of suction when i do the above, so if you (or someone reading this) could give this a quick go and let me know what happens with yours, it would be much appreciated.

The PCV is the unit that consist of the Bypass Valve, Fine Oil Separator and Pressure Limiting Valve in the diagram. It’s located under the Audi RS carbon fibre cover, behind the oil filter.

The PCV is sometime called The Oil Breather Valve or The Oil Separator Valve.

http://forum.rs246.com/viewtopic.php?f=35&t=96292

RS4-AL wrote: I've read that the simplest way to diagnose a faulty PCV valve is to start up the engine then remove the oil filler cap whilst the engine is idling. If the engine suddenly bogs down and there is a strong suction of air being drawn into the oil filler then apparently that means the PCV valve has a fault. When you put the oil filler cap back on it then idles as usual.

Mine bogs down and has a lot of suction when i do the above, so if you (or someone reading this) could give this a quick go and let me know what happens with yours, it would be much appreciated.

I've try it last night and my engine bogs down too. Had mine replace about a year ago and the engineer did mention the vacuum thing when removing the oil filler cap. The thing is I’m still experiencing a slight hesitancy when moving off at the traffic lights after a spirited drive. It would be great if others do this test and state if their engine bogs down and if they are having any problem with the running of their engine.

i,ve only had my rs 2 months but when looking at it before i bought it i removed the filler cap whilst idling and it bogged down and created a lot of suction. the 2 people with me said this was probably to be expected and the car seems to run spot on. hope this helps.