could just be the pump but hotpoint have an ongoing replacement program for faulty tubs if it's under 5 years old they'll do it for labour only as its a design flaw worth getting it checked out get someone in your area with a free call out to poop in and have a look.
jim
November 2007
most likely resonance from a dry running drain pump they're prone to failure on bosch replace it
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix washing machines.