coolant temp sensor?

[gtir bean]

where is it?when i boot my car my temp guage starts to fall the higher up the revs i go.it goes right down to the bottom but as soon as i lift off it goes back to normal again.

 

[Dooie Pop Pop]

about 6inches above the oil filter, there are two there i can never remember which is which :roll: maybe you have a bad earth somewhere