hello,

well, i have read that is "normal" if temp gauge increase when the engine is turned off, but im not sure about that, i had a stat issue on my 07 colorado, P0128 code, so i removed the stat to test it and i saw a internal sealant damage, then i replaced it, the code is erased, but now the temp gauge increase almost 3/4 if i turn off the engine, a logic explanation is the cooling system stop it if i turn off the engine then temp increase but in order to be sure i had compared with the temp gauge on silverado which keep his position after i turn off the engine then decrease with time.

So i would like to listen your experience about that,

 

does this happen at key off or engine off key in run?

 

it happens at engine off key in run

 

like you have stated, you really need to compare vs. the same truck with the same engine option.

IMO if the truck is running between 80 -100 degrees Celcius there is no problem.