VP Temp Gauge crazy

[bootleger]

The temp gauge goes to 3/4 then drops to just over 1/4. this happens every time. I have replaced the thermostat and temp gauge sender the radiatorand waterpump were replaced 8 months ago. Please help!
Thanks Bootleger

[TVR-190]

sounds like the thermo fan is just kicking in and cooling it down

[VP Pursuit]

you may also have a air buble in your system for it to be getting to 3/4. Might be worth bypassing the temp sender on the thermo if you are wanting to run it a bit cooler. I will however make it all a bit more noisy outside due to thermo running all the time.

[strgas]

Have you bled the cooling system correctly or just top up the rad ? is the vehicle on gas ???