Hi,
Had this fault on my new to me 2010 L320 TDV8, needle would suddenly drop to 0 and then bounce back up to normal at random times.

Did some research and there is an oil temp sender in the sump that is somehow tied in to how the dash displays the correct coolant temp, scanned the car and lo and behold open circuit error for it.

Replaced it whilst doing my oil change, part number is 1359056LR.

Hope this helps someone, cheers

Good to know. I assume it fixed it? Visitor from fullfatrr.com
* GONE. 2012 RR Sport HSE SDV6 Orkney Grey. Now being piloted by RRSTDV8
* GONE: 2011 4.4 TDV8 Full Fat. Amazing piece of kit.
* Current. 1974 Lightweight 2.25L petrol. Old skool
* GONE. Freelander GS TD4 Manual MY2013. Orkney Grey with privacy, cold and clearview packs, armrests (a must!) and a spoiler.
* GONE. Range Rover Classic '93 200Tdi Factory fit
* 1949 80" in family since 1975

Yes all fixed, cheers.