I removed the leaking OEM can from my 82 240d. I ran a straight pipe to the intake. I got a lot of sludge in there after driving five years. It didn’t seem to hurt anything.
On my 300d (an 85 with no integrated separator - blowby goes straight to the turbo) I added a kit marketed to the bmw n54 guys. The hose diameters worked well. The images are buried somewhere in my Got a 300d thread. I put this in because I was getting a little smoking at intersections when I stopped after a hard run. It has reduced the smoking.
On my 300sd I wanted to do the same thing. I had been struggling with a cylinder with low compression. The engine had a shaking idle but made smooth power over 1000 rpm. I did a leakdown and suspected ring blowby. So I did a ring soak using Berrymans and that really helped the idle. Suspecting stuck rings I did a bunch of other things like switched to synthetic oil with some Marvel oil added to it. That smoothed it out.
So at that point I theorized that maybe just maybe I’m putting more oil down the intake than I can get rid of down the exhaust. I remember from my gasser tuning days, the best way to decarbonize an engine was to just run it with a slightly lean air fuel ratio. So any oil I can prevent from leaking down my intake is oil I won’t have to burn off. And my SD had a decent amount of oil pooling up in the u-tube. So that was my reasoning. Rate in minus rate out is rate of buildup.
Not sure if it worked because I did a ton of other things to the car to stop the shaking. But it doesn’t shake anymore. It has gradually improved so I figure it’s the new oils or the separator. The ring soak made an initial improvement. I may sound crazy but the MMO + synthetic may have actually helped...that is my feeling at least. (Thanks for the tips Rogviler).
Ok that’s a long story. So I made mine out of an old salsa jar with some stainless steel Brillo pads. I 3d printed the hose nipples. Basically free. Let’s see if I can find the images. Oh yeah the top is 3d printed and the nipples are electrical conduit I had leftover from a project. This was an experiment in cheapness.
I know some of you guys don’t believe in this stuff. Maybe it brings some extra complications like flow restriction on the vent which may cause oil leaks on the engine. But I figured I try it awhile and my cars are running better.
