Agree that is what R1NGA is saying and it is what I do too, in my case I used my compressor to blow through and it certainly cleared the junk but I also took the precaution of relocating the pipe. It is a simple fix and easy procedure to add to the annual maintenance schedule.

Did mine this afternoon and got a fair bit of crap out. I will re-route this pipe so it has a continuous fall to the engine when I reassemble it.

I still cannot see how to vents in the tank to atmosphere when the tank cap is screwed on airtight. Unless the small vent from the top of the crank case to the throttle body does the job.

There is no vent to atmosphere, by design. That small vent through the throttle body is all that is required. And venting this way has the added benefit of creating a net negative pressure in the crankcase which aids the oil seals, as well as reducing emissions. Which is why all the OEMs went to this type of set up in the 1960's.

From an engineering perspective, going back to atmospheric venting is a retrograde step.

Sorry for any confusion, but yes, both ends of the breather hose are disconnected when I blow the gunk out into the bottle (rather than onto the garage floor....). Ironically, my vent hose was very neatly routed and P-Clip'd by the factory during the chassis change, but I will consider re-routing with a permanent downhill slant if the mood takes me one day, but in the meantime I will just clear it out a couple of times a year using this method.

As noted elsewhere, the whole gunk in the vent line issue goes away if you simply get the engine oil up to full operating temperature (220F+) most every time you take the vehicle out for a drive.

As my father in law once observed (with some measure of disgust) when he saw me using glass cleaner on the underside of my S1 Lotus Elan: "Just go out and drive the damn thing!"

the worse wear on an engine is the little old lady who only drives to church

The mind boggles at the idea of a little old lady driving an M3W today! Cue photo contest...

I relocated the line this weekend. Even though I drive to get the engine up to temp, you can see what was in the vent line


As the new line would cross over the transmission I slide it through a 7/ id hose to absorb the wear and tear. It is the shiny black hose. The clear braided hose covers the oil return hose to protect it as well

That dip in the line that MMC put there was a bad design. Your reroute and shielding should solve the problem.

yes there was a good 6 inches of line below the vent hole.... usually 6 inches would be a good thing