Just changed water pump, tensioner bearing and toothed idler to try and solve annoying engine noise, hard to explain but it's like the sound from the power steering pump wine coming from the front of the engine, aux drive belt off !!. Thougt it was the water pump bearing but it hasn't made any diff. Have changed 2 idlers that sounded dry, have another that's slightly noisy but only ever so slightly, since changing idlers engine seems otherwise quieter but this noise is still apparent.

Could it be the oil pump? or something else?