I hate it when I do this sort of thing.

Since it was the most convenient thing to remove in order to attach a vacuum gauge to my M60 3.0l engine, I removed the one-way vacuum valve, the one that sits near the rear of the engine, under the engine top cover and sound insulating pad.

Then, of course, I had a 'duh' moment, when I realized I just don't quite know which way it is supposed to go. Say this thing is an arrow, with the arrow pointing in the direction that you can blow through it, which way does the arrow point? Forward or backward?

My particular valve is white on one side and black on the other, and there are black and white vacuum lines that it hooks up to, so I guess I would guess this might mean something.

Anyway, thanks, sorry.

The arrow points towards flow

Right. Good one. :)

I guess I figured out that said arrow must point backwards. According to the parts diagram at realoem.com, someone reversed the colors of my vacuum hoses, which added to my confusion.

vacuum from rear of engine, so the arrow points back. It's really the only thing that makes sense, now that I have paused to think about it for a second.

Thanks

Rolf