There are two sensor/sending units near the oil sandwich plate that holds the filter. I would order new sensor/sending units, and in the meantime clean/inspect the corresponding wires.
Personally I will replace everything I can that does not look new or looks suspect on my 110. If it clears up a problem I toss the old one in the trash, if not then I keep the old as a spare/back-up part. I only replace with genuine parts.
1995 NAS Defender 90 AA Yellow #2986: Current
2009 Range Rover Supercharged Black/Black: Current
1993 NAS Defender 110 #375/500: Sold
1995 NAS Defender 90 Soft Top Beluga Black #2556: Sold
1991 Range Rover Hunter Green: Sold
1997 NAS Defender 90 Station Wagon Portofino Red #128: Sold
1993 NAS Defender 110 Beluga Black #215/500: sold