Printable View
Hello,
Does anyone here know what the purpose of the circular contraption is for inside of the valve cover? I couldn't locate a replacement part and was forced to purchase an entirely new valve cover. I took the old one apart which broke because it was brittle, but inside was an orange rubber ( ripped) with a spring on top. I can't seem to locate anything about it online. I would greatly appreciate any help about it or the name of that specific part.
Thanks!
Art.
Do you have a pic for the part in question?
Bet it is a pressure equalization valve for the hose that goes into the oil cover from the air intake.
Hi,
Yes here is the part. Thanks!
Attachment 10811
There are parts missing from that round thang. If you look at this picture:
Attachment 10812
You can see the vacuum line and then the vent to the side.
It's known as the engine vent.
I found this on the chevy cruze forum, it make sense to me:
Quote:
More PCV and valve cover goodness
So I originally though that oil was blowing out of my oil cap from damaged caused by my oil catch can issues. So I was going to pull off the valve cover to see what was going on. Obviously the PCV system was blocked some how. From everything I've rad and heard from techs at GM, there are two PCV valves, one at the turbo and another in the valve cover. The one in the valve cover is not serviceable (will get to that in a minute). Last time I had this problem they replaced my valve cover.
So, I took off the valve cover to check things out.
0929131711a.jpg
Markj2222 mentions that the baffles are enclosed. Usually baffles help keep oil in the valve cover while letting air vent out. I thought maybe mine had collapsed or something. As he said, there is an enclosed channel that air runs through that is in fact sealed off. Looking at the system, air coming into the valve cover will travel over to the cam gears and into the head and will make their way up into the valve cover. The air goes from #3 and #2 around the valve cover and over to #1 where it travels to the port on the intake manifold that connects the PCV tube.
0929131711b.jpg
So, what they heck?! What is my problem? I figure there is something inside the channel that is blocking air flow. So I flood the channel with water and force air through it. I do all sorts of tests on it with air and blocking each port, forward and back. All seems fine. Then, just out of curiosity I have a look at that round thing that is across from the oil cap. I always wondered what that way. So I look at it close and notice that it has a little spout that is open. It's a vent! Then I notice that the channel forces the air into this area before it goes to #1 to exit the valve cover.
0929131829.jpg
Inside of this thing is a diaphragm! Look in there close and you'll see an orange rubber piece. There is a spring attached to it (at least that what it feels like when I press down on it with a tool). So there isn't a "valve" in there, it's a diaphragm and apparently when the PCV system isn't working correctly it gets jacked up. So I clog up all 3 ports and blow air into the channel. Out comes water from the that tiny vent.
The reason why it's not serviceable is because that channel cover and the cap to the diaphragm are sonic welded in place. I'm sure I could have gotten them off (maybe without damage) but I doubt I could get them back on in a way that they would be able to handle the pressure.
So, this is how our PCV system works and what is under/in that valve cover.