morphius

Hi Guys, Please someone help me :( Havent long owned my N plate Xantia 1.9 TD but have noticed there is a very strange noise coming from the engine. Hard to describe it but its kind of like a belt noise? Slipping? I got underneath and had a look and with legs sticking out the front of car when looking up I can see silver casing (gearbox?) and the noise seems to be coming from there. There is a hole in this casing and I can see what looks like a belt inside being driven, its dry in there no oil etc. The car runs fine but sometimes the noise sounds terrible and othertimes it dont sound at all! Im really stuck with this one and am afraid its the cambelt or gearbox is going to pack up. If anyone has any ideas please HELP! Regards, Graham.