Mine is doing the same. The problem is the auto evaparator defrost. The noise is ice build up within the fan housing, the fridge should auto defrost every say 6 hours, i suspect that the defrost heater has malfunctioned, parts can be sought from currys spare, google currys spares and you will be led to their website which has any part you want. To see if this is the problem, turn the fridge off for a day leaving the door open, you will find the noise will have gone, however it will return in around a week.
R Crossfield, May 2007
