My 380SEL's oil gauge has started jumping around, this time last week it would always read full. Now it jumps to anywhere between empty and full... This in itself is worrying enough, but when the gauge reads empty the engine starts to rattle... and doesn't stop until the gauge returns to something above 1.

This sounds like a serious problem, so I'll be taking it to my tech, but I figured that it'd be a good idea to delve into the wealth of experience on this board and maybe save some time.

The oil resevoir appears full, and I can't find any leaks. Does anyone have any ideas?

Thanks,
Nic