Hi my 2011 Astra J 1.7 CDTI has a strange noise that is getting more and more frequent, when i accelerate away and dip the clutch to change gear, there is a ghostly noise that starts off quiet and gets louder, it got worse when i changed the fuel filter, but then became less common for almost a year, but has now come back with a vengeance. I almost think it could be to do with fuel pressure?
Just wondered if anyone else had experienced this and how they got rid of it. The car itself drives fine