XP3 whistle

[Plan-B]

just got myself a Rena XP3 filter for my 90 gallon tank. I set it up as it says to in the instructions with one exception. One of the water lines was too short so I replaced it with a prefab Fluval hose with fittings on each end. The replacement hose was too long and could not be cut to size because of the fittings so I coiled the extra behind the filter. (some of it sits lower then the power head on the filter). Anyway, Things worked fine for a few days after start up then while I was playing with the quick connect hoses it started to make this high pitched whistle sound. The sound is coming from the back of the tank and not the filter itself. If I shake the hell out of the outlet line (this is the line that came with the filter) I can change the pitch of the whine / whistle and even temporarily stop it.
This however lasts seconds and then the whistle is back. Any ideas on how to stop the noise?

Thanks,
Plan.

 

[Plan-B]

If anyone is interested I solved this problem quite simply. I drilled out the holes on the spray bar to a slightly larger diameter. No more whistle.

 

[canarsie11]

Had same problem