R50/2 noisy breather pipe

[bmw_dave]

I'm working on a '68 R50/2, recent engine overhaul, and I'm getting some noise from the breather pipe. It stops when I put my finger over it, it has some pressure there but no oil or smoke. It almost sounds like an exhaust pipe! There's a lot of pressure at the dipstick, also.

[wa1nca]

their was some post about that in the past but couldnt find it, after a rebuild
If I remember correctly if you remove the dip stick and the noise go away then it is normal and should go away in time
I think it was because of a new rear main engine seal
Tommy