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Could anyone enlighten me with some information on the number 3 in this drawing?
It says it's a pressure regulating valve, but what does it actually do?
Seems mine is trashed, could this be one of the reasons my car is running so bad? I can only hope..
Its a very low res drawing, but I think that's what's being discussed - it regulates vacuum pressure in the crankcase - essentially allowing the engine to breath out the dreaded 'blow-by' gasses.
Under vacuum the engine ingests the blow-by gasses into the inlet manifold.
Under boost the engine ingests these fumes at the MAF hose. Yeuch...
Split PCV hoses and faulty valves can cause unmetered air to enter the engine. Blocked PCV hoses give the engine breathing problems as you might imagine. There is also a flame trap within the PCV system which can gunge up the system with moisture ridden oily crap that collects over the years.
Just removed a few of the hoses connected to the valve and they are FULL of the moisture ridden oily crap you are talking about Paul, guess it's time to clean up.
Yeah they are pretty nasty - check them carefully for leaks as the oily crap causes the hoses to soften over time & they can split. Some new PCV hoses from Audi can be ludicrously expensive.
It maybe time to consider a catch-tank / cyclone system !
Remember to change the flame trap (i think number 5 on the diagram) as you can see it gets really clogged up.
Yes it's number 5, called "flame deflector plate" in the diagram.
It looks like it's supposed to be in the short hose between the valve and the metal tube. Well.. I just removed it and there's nothing in there. Wonder where it could be.
Mine was stuck right up by the bend of the metal pipe marked 6A. Needed to use some very thin and long nosed plyers to get a decent grip and pull it out.
Originally posted by lees2
is this little gizmo a must?
I suppose it's there for a reason, but then again those audi people might just be playing it extra safe..... or maybe not.
I dunno how important that flame arrester is, but Audi must have figured there is some sort of possibility (say with an inlet valve stuck open) that combustion could get into the inlet manifold. Whether that would be enough to send a flame front thru the PCV system and start an oil fire in your sump is another matter. Sounds pretty implausible to me, but Audi wouldn't have put the part there unless there was some sort of potential hazard in running without it.
Just open the PCV system today and I could not believe the amount of crap I found in there. I am sure the system was completely clogged.
Flame trap was a black mix of metal, oil and debris and it took me 15 minutes with water and degreaser to clean valve (number 3) and the amount of things getting of there was ridicously.
Will get a new flame trap but I think is time to install a catch tank system, plus I could use the unused EGT hole in the Downpipe to create the vacuum.
Anybody could help me shorting a correct catch tank in the Uk, because they will laugh at me here in Spain.
Cheers
PS Could the hesitation I was having on the engine at WOT be related to this?
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