Zanussi WJD1457W - noise during wash and rinse cycles?

My machine seems to be washing ok but has developed a constant deep groan during the washing and rinse cycles - the best description I can give is it sounds like an idling diesel engine. The sound doesnt change whether the drum is moving or stationary, and is not there during draining or spinning. I have also noticed that the jets which used to spray water on to the clothes during washing are no longer working and wondered whether this may be related?

Any advice gratefully received!