Oil from Anti-Shudder valve?

[Mario]

Today I was having a quick look for something in my engine bay when I noticed some oil on the oil filter housing and some surrounding bits. Looks like it has come from the anti shudder valve as depicted in green below.


The engine is a 2.0 TDI 170, BRD engine code. EGR was replaced May last year with a new Siemens part and the car was then serviced last June. At those times there was no oil at all. So it's happened in the last 11-ish months, and to be fair there is not a lot of oil.


Looks like only 100-150ml has been lost in that time. However if you look at the pictures below where I have circled in red it looks like a seal has "popped" out between 2 mating surfaces. That's where it looks like the oil has come from.


Is that how it's supposed to be? I have seen some used genuine ones on eBay that have the same thing, but new Siemens parts that don't have that.


I plan to clean it up and keep a close eye on it. Is it simply a worn seal or something more sinister?


Any thoughts on the matter welcome.

[Rob69]

It's hard to make out in those photos but it looks like when the EGR was replaced the o ring between EGR and anti shudder / intake flap has unseated itself and become jammed between the two. If so this will be a leak path for boost air and that carries a bit oil residue from the crankcase breather. It look like the ASV needs dropping off and a new O ring fitting.

[Mario]

It's hard to make out in those photos but it looks like when the EGR was replaced the o ring between EGR and anti shudder / intake flap has unseated itself and become jammed between the two. If so this will be a leak path for boost air and that carries a bit oil residue from the crankcase breather. It look like the ASV needs dropping off and a new O ring fitting.

It's not that, the EGR is the newer looking silver part in the middle of the 2nd pic. This is part of the anti-shudder valve. The seal that has popped out is between the cover for the geared mechanism of the ant-shudder valve and the main body of the anti-shudder valve. Had a reply on Audi Sport and it looks like I have the same as this guy.....only his seal wasn't leaking....

http://www.audi-sport.net/xf/threads...e-woes.291209/

According to his mechanic mate, it's a common issue. However mine seems to be working fine with no issues other than the oil. Will try and wipe it down, give it a clean with brake clean and see how I get on. Hopefully I can get hold of another seal....failing that some RTV will do!

[Rob69]

Good photos on that thread link thanks - looks like it would just be a soft neoprene gasket that's squeezed out then. I've chopped up a knackered one of those ASV's to see what was inside and from memory there is an o ring that seals the gear driven shaft as it goes through into the airstream and butterfly flap, the oil maybe is passing that shaft o ring and the boost air pressure has pressurised the gear casing blowing the neoprene gasket out ?? just a theory.

[Mario]

Just a little update, incase anyone is interested or has this issue in the future. Took the anti-shudder valve off the car today and it looked exactly like the pics in the thread linked to above. It was full of oil! Used nearly a full can of brake / parts cleaner on it and cleaned out all the oil inside the unit & the cover until it was just clear fluid coming out. Let it dry fully. Put it back together and tested it....worked perfectly! Valve opens and closes when it should.

Also, that bit that looks like a seal has "popped" out is supposed to be like that! There is a cutout in the body for it. Must be a vent of sorts. Also cleaned off the spilled oil in the engine and been driving it all day. No more has re-appeared from the anti-shudder valve