E36 fuel gauge with mind of it's own

[sniff petrol]

My car's tank's about half full, however on the way to work this morning the gauge was indicating that it was very near full. I thought it might settle a bit but when stopped on a flat bit of road it still saying about 3/4 full. I've taken the fuel cap off and on again in case there was an airlock but it didn't hiss when I took it off and hasn't made the blind bit of difference. Any ideas?

[Shropshiremike]

sniff petrol said:

My car's tank's about half full, however on the way to work this morning the gauge was indicating that it was very near full. I thought it might settle a bit but when stopped on a flat bit of road it still saying about 3/4 full. I've taken the fuel cap off and on again in case there was an airlock but it didn't hiss when I took it off and hasn't made the blind bit of difference. Any ideas?

I've noticed the E36 ones are quite strange in that if you've been driving quite economically recently and have a decent amount of juice left they can almost seem to compensate? (i.e read higher than you expect ) Have you got the OBC? If so, what's the range?
Have you had the loose wire on the sender problem yet? ( although that usually means the empty light comes on )
Sometimes the sender seems to take a while to catch up after you've refilled as well? Are you sure you haven't got a 3/4 tank?

[sniff petrol]

Thanks for that Mike. Yes to be honest I had been driving it harder than normal as I'd put some diesel injection cleaner in the last tank of fuel and was trying to do an 'Italian tune up'

Maybe now I'm driving a bit more sedately it's gone back to normal? And no it doesn't have the fuel consumption readout as it's not an SE model, just the basic one.