Hey, I looked at a bunch of threads on booster pump noises, but none of them seemed to match my issue.
I've got a Polaris booster pump - new last year. Nothing's been done since that except for the replacement of the hose coming out of the top (return line?). The booster pump is set up to only come on when there's power going to my main pump.
Anyway, my main pool pump motor was very very very loud - it was on its last legs and died Sunday - just stopped running altogether. So for the first time ever, the Polaris pump was running on it's own for a little while. In addition to it's normal running sound it was making a sound like an old washing machine agitator - whoosh, whoosh, whoosh if you know what I mean. Not super loud but noticeable.
So I replaced the main pump motor this morning and get it all running. Turned on the main pump and then cleared the air out of the line. All good. Then I turned on the Polaris just to test- again the whoosh, whoosh, whoosh sound. Much more noticeable with the new quieter main pump motor. However, when I tried to record it with my fancy equipment (my phone), you can't hear it over the drone of both motors).
Honestly I don't know if it has always made this sound or not - is it anything to be concerned about? The Polaris seems to be working just fine.