Wierd fuel gauge issue

[markroad]

My 316 has a very wierd fuel gauge fault and I wonderd if any of you guys could help?
When the rank is full the Reading is correct, when it gets down to about quarter full the gauge goes wild, fluctuating like mad up and down - it's really wierd
any suggestions would be helpful!

[danbear]

check the brass not on the back of the cluster. they're known for coming loose or even falling off. if not, you probably have a dodgy level sensor