The crank and rods do not "throw" far enough into the oil pan to contact the oil that is lying in the pan. The only time the oil from the pan contacts the crank is when it gets sloshed up onto it from vehicle movement. Most, but not all, high performance models have a windage tray to scrape any excess oil off the crank. Oil does otherwise get flung off of the crank and it can get frothy and airated from this "whipping" action. The baffles in the valve cover are there to keep oil out and nothing more. Oil gets flung around and squirted all over the place under the valve cover which is why they are there. Have you ever ran an engine with the valve cover off? If you have, then you know what I'm talking about and would see how much oil gets thrown around all over everything. The reason for the oil getting past the PCV valve is the added internal pressure from the turbo forcing the oil that gets flung onto the valve cover out through the PCV, as well as the vacuum from the intake pulling it out, and the other hose from the valve cover to the air box which is why there is a spong type filter in the air box where that hose connects to it. N/A cars do not have this added internal pressure, which is why they do not need an OCC, because the oil doesn't get forced out through the PCV. If it were an oily vapor/fog that gets past the PCV valve and collects in the OCC, then this would happen on normally aspirated cars as well and they too would benefit from an OCC, but that isn't the case and none of the N/A cars I've worked on had any oil in the hoses connected to the PCV valve. The rings do also have an effect on this too, but very little.

 

Dude, the ways the oil gets flung is from oil draining back down from above, hitting the reciprocating assembly, from sloshing during vehicle movement and from the oil travelling through the crank and rods. The oil is constantly leaking fom all sides of the rod and main bearings while the engine is running. They are only plain bearings and lose some oil continuously during operation per design. The oil pump just has to be adequate enough to pump enough volume to compensate. When the engine is new and "tight" that leakage is not severe but it is always there. That oil gets flung off the crank and all around and churned into a mist.

The added internal pressure from the turbo you eluded to is from where? The pressure in the crankcase? How does the crankcase get pressurized when it should never be? RINGS. Blowby from rings. Plain and simple. The only possible exception to this is a head gasket in which case you would have other indications things are not right.

Timing chains (on other engines) and the whole valvetrain also add to the oil being flung around as well. I am a mechanic and I have run engines with valvecovers off and yes it makes a hell of a mess.

Now as far as N/A cars needing OCC's yes they could use them, but their problem is not as severe, because they do not get excessive crankcase pressures untill the rings are so wasted that the car won't run without smoking anyway. But the problem is still there. Absolutely, 100%. Every pcv valve I have ever changed had some oil in it. Every one. Usually, on the older cars, the pcv hose was plumbed into the intake behind the carb on older engines. Ever wonder why the back spark plugs always look worse than the front ones? Oil from the pcv. Nowadays, they route it into the intake right around the throttle body. When the engines get some miles on them you'll see oil in the intake if you look in there with the TB off or opened. On any engine. If the intake is shaped so the TB is lower, you'll see oil leaking out around the air inlet hose (like on our cars) and the idle air solenoid will be getting all gummed up and will need periodic cleaning. My 3.0 mitsu v-6 even had this problem. The design of this intake is one reason so many people have noticed a "problem' It slopes down and the oil runs out the TB and out of the charge air tube clamps. If the intake was shaped different and the oil went toward the cylinders, or it puddled in the intake till burned, we may not even be using OCC's cause no one would've noticed.

I see something related to this about once every week or two. I work on deisel trucks. When we get a truck in that is constantly dripping oil from the road draft tube (read old style pcv vented to the atmosphere) (yes, they still do that on trucks) it is about 90% chance the air compressor and about 5% chance the oil/air seperator screens have fallen out inside the valve cover. 5% chance something else like the engine rings as they seldom wear out. Why this is related is if you see how the air compressor is driven. On newer deisels the air compressor is mounted as an accessory usually to the lower left backside of the accessory drive case on the front of the engine. The compressor is gear driven, usually two cylinders and uses the engines oil and coolant system. Like a little piston engine sitting next to a large piston engine. What happens when the compressor rings go bad is the excess pressure escapes through the bottom of the compressor, into the engines accessory drive, into the engines crankcase up into the valve cover and out the road draft tube. The road draft tube is almost always coming out of the back of the valve cover. The farthest it could be from the compressor. It amazes me that all that oil could be a result of a bad compressor but it usually is. Thats just 2 little tiny pistons as compared to the other huge 6 in the actual engine.

I'll give you this; A healthy engine should not have a lot of oil in the pcv system, but it may always have a little.

 

[sm=wtf.gif]
I'm completely at a loss!!! This whole empty oil catch can thing is bugging the **** out of me! One, I drive that car harder than $hi&. I'm use to having to empty that catch can every 3 tanks of gas. I changed the PCV valve. I ordered it directly from a dealership. I didn't care that I was being overcharged, I just wanted the dang thing. I told Nic that it was still NOT catching. So, yesterday he told me to just get on it even harder. So, I did. I didn't even get 100 miles on a half of a tank I was boosting so much. STILL NOTHING in the catch can... So, this morning, I start it up and pop the hood. What little residue that was left in there from the last time I emptied it, was being blown around by the air that was obviously passing through the hose with no problems. I feel like beating my head against the concrete cause this is frusterating me beyond all belief...[sm=headbang.gif]

P.S.
I love you too baby[sm=patriot.gif]

 

Got a digital camera? Post some pic of your OCC setup. Maybe someone can spot something from that.........

Dusty

 

Every PCV valve that I have messed with had oil residue as well, but I haven't seen a N/A engine have oil past that point more than an inch or two at most.

I'm not about to continue the long drawn out back and forth ordeal on stuff we already know and differ on opinion about, so I will simply say this. The turbo increases the cylinder pressure raising the compression ratio and increasing blow by past the rings. A high compression N/A engine does the exact same thing. Why then is it that the turbo engine blows oil by the gallons past the PCV valve and the N/A engine barely wets the PCV valve with oil?

 

This may sound very simple, but check that none of your lines are being kinked when you close the hood.