I too have the 'rumbling noise' under the bonnet and also extremely heavy power stearing when the car is stationary and idling, but becomes lighter once the car wheels are moving slightly or with higher revs. An additional problem I have is that the battery drains if the car is unlocked for more than 60 mins or if the ignition is on in the final position for about 20 mins. Do you feel the battery issue is also a symptom of the alternator belt issue (writing this now it would seem so) Thanks, Angus