Filter Rattle

[laylacast]

I've got a eheim liberty 100 filter that rattles more now then ever. I
cleaned out the motor fan casing from debris, and it runs noticably quiter.
However, it still rattles enough to stop me from sleeping (tank in room).
Any suggestions/experience with this filter? Can I lubricate the casing with
vaseleen? Also, I noticed the rattling is louder when I keep the lid on
(because it echos). Any problems if I keep it off? I know this is what you
get when you buy a cheap filter, but I'm sure someone out there's got some
experience fiddling with it.

Thanks

Mike