Temperature gauge not accurate

[Cascadia Farmer]

Has any one seen this:

The temp gauge on my Massey 255 reads dead cold on startup (normal) and stays there for about first 15-20 minutes of running then shoots right up to hottest hot. Its done it since I've owned it (about 1 yr) and I never once believed it. So now I actually want to know what temp the thing's running at. I'm suspecting its either electrical, a faulty gauge, or the sending unit. Any tips from one who's been down this road? Is there any reason to think its the thermostat itself?

Thanks for any advice

 

[banjodunn]

Gday i would suspect that you have a faulty sender unit that is unless you are actually getting that hot a quick feel of the top rad hose and the cyl head as it is warming up should tell you if the thermostat is working the head will get warmer than the hose until the t/stat opens but be careful doing this as it will get very hot most t/stats don't open til about 85c. Hope this helps


Jon

 

[Diamondpilot]

Yes, sounds like either a bad sending unit or bad gauge. Replace both and you should be in the clear. Also before you do that check the wiring running from the sender to the gauge. If its older it may not have a wire but a metal tube instead. In that case also replace.

Chris