For you I-CTDI owners it's becoming more common to see crank pulleys become noisey or even fail. Signs of failure can be intermittent ticking from the belt area and a visible wobble. In the main it seems to happen on more high mileage engines. A lot more common is oil leaks from the crank oil seal or above. This in itself is bad enough but if not sorted out engine oil makes the rubber damper in the crank pully swell and eventually fail. The crank pulleys fitted to diesels comprise of an inner hub and outer race separated by rubber. This is basically a damper to lessen engine vibration. The big tip here is if you have an oil leak around this area don't just ignore it! Crank pulleys are expensive to replace and fixing that oil leak in time can save you that £400 See how the rubber has swelled Behind the pulley. This then rubs constantly against the chaincase creating annother noise in itself. And the other picture shows where it was rubbing and extent of the oil leak from the crank oil seal in question.