whittlingwoodpecker

hi guys
right i have read through a lot of posts about overheating and have done this to diagnose problem....
thermostat replace and test with old one both work
new viscous coupling
new radiator
bled system properly
checked the water pump (taken off feed for heater and reved engine to find i get a lush warm shower)
pretty sure its not hg as no white smoke and no bubbles coming from resvoir plus itr dont eat any water.
now my question is to you all is does the temperature sender deteriorate over time and maybe read higher?