wtf temp gauge is crazy!

[blk&blu03]

soooo posting for the second time i hoppe that it is is as productive as the last post. . . . so here is the issue everytime i warm my truck up in the morning the temp gauge gos' all the way to hot and then drops back down to reg temp and runs fine and never over heats except for that brief 2-5 sec that it get hot
-only happens when i first start the truck
-never happens when driving
-i think its the thermo but not sure
anyideas much apprieciated!?

 

[Big Jim M]

2-5 seconds.. I'd be betting on the temp sendor.. If thermostat it would be far slower or not at all.
Could also be a simple adjustment of the lectric connection at the sendor... might just be dirty or such.
Big JIm

 

[blk&blu03]

cool

thanks man ill give that a try