Irratic temp gauge

[zxr_oli]

Lately while riding along i've noticed that every so often my temp gauge will suddenly jump up to about 1/3 or 1/2, but will drop back down after a couple of secs.
Should i be worried, could it just be where there thermostat is opening? Or maybe there is air in the lines?

[masterofinsanity]

sounds like its air in the system, have you checked the level lately?

[zxr_oli]

I refilled the coolent when i changed my rad, so it's a possibility i let some air in.
Level looks fine, but will have to change it all again to try and get the air out.

[carsounds_dan]

I like to "flush" the system as-well, hold a male ended hose into the rad filler and turn the tap on, hold it in tight until you get a steady stream of water out of the water pump bolt hole and the expansion tank, then you know it's flushed.