Maxi-jet Making Loud Noises

[KraKen]

Ever since I added another piece of tubing to the intake of my powerhead it's been making a loud rattling/humming noise and the flow has lessened.
It's never done this before and I can't figure out whats wrong with it. The tank's in my bedroom so this noise is really annoying

Does anyone know what the heck is wrong with it and how to fix it?

 

[robbo87]

this may sound stupid but is the air pump touching anything hard? also do you have an air flow valve on the pump?

 

[KraKen]

Well it's a water pump not an air pump... so, no