S15 Heat gauge issue

[ryankidd]

Help - YouTube

I made a terrible video of the problem, bare with it for a minute or two until I get the hang of filming it.

So here's the problem;

Heat gauge shoots up and plays up after the car has warmed up.

Things like
-rolling in neutral and braking makes it shoot up.
-Pushing in the clutch/letting out the clutch it shoots up.
-Aircon turns off when the gauge plays up.

It seems like the is a sensor that I have missed that may be playing up.

Things I have tried;

Replaced radiator cap
replaced thermostat
checked all wiring around intake

Not sure where the sensors that I should be checking are.

Anyway, I hope someone can help, and I am glad I found this forum, already found out some great info on my car!

- Ryan