Temp gauge reading high, needle up in the red, no fans??

[skeggyrik 3]

Of late the temperature gauge which has always been rock steady has been heading for the red and staying there.

This is in my Mi16 converted 205

No fans, no overheating and the gauge can be up there in the red very quickly after a cold start. Otherwise no adverse running, no stop light. 

It's almost like the gauge is suddenly reading a third higher than it did before.  It's done it the last three times out over the past month. It did it once before a few weeks back but then settled back to normal operation. 

 

So I am thinking of checking for air in the system, open bleed valves, top up coolant as required. 

Could it be a duff sensor? there are 3 of them on there, from memory it is the bottom one for the gauge. (where to get these from?)

Sticky thermostat?

 

Anything else I should be looking for?

 

No white smoke (steam) from the exhaust before anyone suggests HG failure. I'd hope not. 

[j_turnell 137 3 Cars]

Does sound like it could be a duff sender, intermotor sell them, available from most parts places or ebay. You can also try earthing the signal wire out on the block with the ignition on and make sure it goes to full. Worth checking connections at the brown multiplug also if you still have this and the wire itself for general condition.