Oil pump and balance shaft

[Jimmytheking007]

Hi I have a 2008 A4 cabriolet done 36000 miles with a BWP engine code. I read that certain engine codes suffer from the failure of the oil pump I'm / balance shaft and a modified one now is geared as apposed to the chain. I have rang 2 audi dealers and one is saying it's a chain and the other is saying a gear driven. Can anyone help and should I be worried as the car has only done such low mileage though it is 12 years old. Many thanks.