[floydpink]

I think the bottomless portafilter might be the source of some of the leaking.

It is supposedly for "all E61's" but doesn't seem to fit nearly as snugly as the other portafilter the machine came with. It came from espressoparts.

In other words, the Brasilia portafilter is snug when the handle faces almost directly at me, or 6 o'clock.

The bottomless pf needs to go almost a 1/4 turn further to fit snug.

Oh, and it's a tiny stream of coffee that sometimes squirts from the pf where it locks into the grouphead.

I believe the whistling might be normal and a sign of built up pressure as it occurs when the pressure builds during a backflush