Oil/air separator
Oil/air separator I've been through 3 different variations of home-made catch can for the PCV line, but they all had this problem that they'd eventually get filled up with sludge and I really didn't want to clean it out. Anyway I happened to be reading the Haynes manual for our Grand Prix, which covers a bunch of different engines, and noticed that one of these engines (4 cyl. I think) used an "oil/air separator", with no PCV valve at all. There was one small picture, just a rectangular box with a line so the oil can drain back into the valve cover. Anyone here happen to know what's inside one of these? Or if they really work? I'm thinking I might get one and just mount it somewhere where the oil could drain back. Right now I'm back to the stock setup, but sucking oil into the TB I'm sure.
On The Tree
Joined: Nov 2002
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From: Corpus Christi Texas
Re: Oil/air separator My son's '98 Cavalier with the Izusu-like 2200 engine has a valve cover air-oil separator also. I think that it works at all because the vacuum source from the air intake is in front of the throttle body, which is to say, it works because there is so little vacuum there, that it doesn't draw much oil into the intake because it doesn't draw much vacuum.
As a test, I plumbed tubing into a vacuum source below the throttle body on the Cavalier and added a filter and drew air-oil past the separator to see how much oil could be pulled past the separator. After a 1,000 miles the amount of liquid in the filter was approximately the same as I get in an identical pcv filter system on my '98 Camaro.
So the air-oil separator you asked about is not more efficient at removing oil than the pcv setup on a '98 Camaro. However, I think this internal air-oil separator system indicates that very little vacuum is necessary for a functional pcv system.
Internal air-oil separators are not unusual. I think that GM's 3800 V-6 and the 4.2 Inline 6 have them too, just based on my inspection of these engines.
As a test, I plumbed tubing into a vacuum source below the throttle body on the Cavalier and added a filter and drew air-oil past the separator to see how much oil could be pulled past the separator. After a 1,000 miles the amount of liquid in the filter was approximately the same as I get in an identical pcv filter system on my '98 Camaro.
So the air-oil separator you asked about is not more efficient at removing oil than the pcv setup on a '98 Camaro. However, I think this internal air-oil separator system indicates that very little vacuum is necessary for a functional pcv system.
Internal air-oil separators are not unusual. I think that GM's 3800 V-6 and the 4.2 Inline 6 have them too, just based on my inspection of these engines.
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From: Hot Rainy Humid +2000 DA South Florida
Re: Oil/air separator Here is my new PCV system with an oil/air seperator inline. When I need to drain it I put a foam cup under it and turn the black ****. Take about 10 seconds to drain it.
Originally Posted by patSS/00
I've been through 3 different variations of home-made catch can for the PCV line, but they all had this problem that they'd eventually get filled up with sludge and I really didn't want to clean it out. Anyway I happened to be reading the Haynes manual for our Grand Prix, which covers a bunch of different engines, and noticed that one of these engines (4 cyl. I think) used an "oil/air separator", with no PCV valve at all. There was one small picture, just a rectangular box with a line so the oil can drain back into the valve cover. Anyone here happen to know what's inside one of these? Or if they really work? I'm thinking I might get one and just mount it somewhere where the oil could drain back. Right now I'm back to the stock setup, but sucking oil into the TB I'm sure.
the box ur talking about is on most gm 4cyl's that were a quad four 2.3 and 2.4l engines early 90's-on
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Originally Posted by JGKadell
i just used a small Cambell housfield air/oil sep from the sone and put it between the intake and pcv. works great
10 bucks and some 3/8's hose = done! 