After doing my research and trying everything, nothing works. The noise unquestionably came from the impeller but I have no clue where exactly the nose is generated.
Is it from the magnet hitting the well? I tried lubricating the magnet and well with vaseline and didn't make a difference. Is it from the magnet and blade assembly rattling around the axle? I tried to lubricate the axle with no success without removing and likely damaging the bushing. Is it from the worn out bushings rattling around the seats? I glued the upper end of the impeller with silicone to the seat in the shaft to stop the movement, and it didn't make a difference. My final trial was to replace the impeller with a new one.
Looking up Big Al and other mail order places, a new impeller for Penquin 330 costs about $14, so I ended up buying a new Penquin 330 for $20 after a $10 rebate from manufacturer. PROBLEM SOLVED!
I have many old HOBs that are getting noisy due to worn out impellers. I am looking for cheap replacement impeller as I don't want to throw away old HOBs that are working perfectly fine except for the noise. Any suggestions?
