noise from eheim 2217

[aquascapist]

Hi, my 2217 had been running trouble free for the last 8 years. Two days back it started making this noise as if there was an airlock. so I dismantled and cleaned the impeller which was full of gunk. Reconnected the filter but the noise is back. Checked for cracks on the impeller and it looks fine. I cant understand what appears to be making that sound...Any ideas how to resolve this
Thanks!!

[sushant]

Check the hole in the impeller through which the shaft passes, with time it looses it shape thus making the impeller wobble.

[aquascapist]

yea it does seem to have lost a little shape..it bugs me though that it started becoming noisy almost overnight.

[aquascapist]

figured out the problem..the rubber bushing was not fitted properly...Also lubed the impeller...seems to help for now. Thanks!