just about to buy an R33 GTS-T but there seems to be a sound coming from the engine while it's idleing. it sounds like a bearing kind of sound...any ideas on if this is a problem or any ideas on wat it is...guy says it's been like that for 10,000kms and his dad is a mechanic and says he doesn't think it's anything...car is going for $15,000 probably and it's in really good condition..any help really quick please