coolant temp jumps around
 

i recently broke a fan blade and it went through the radiator. so i just put a new radiator, radiator cap, fan, fan clutch and a new thermostat in and the trucks running great again but i noticed the temp acts funny once i get it up to operating temp. when i was cruising down the highway today i was keeping my eye on the guage and it warmed up to 190 degrees within a few minutes, stayed at 190 for about 30 seconds then drops back to about 160 in no time, then slowely climbs back up to 190, then drops back again, climbs back up, drops, it just does this over and over the whole drive down the highway. could it be a bad chinease parts store thermostat?

probaly,maybe ya should check water pump to be safe

thermostat is opening at around 185 to 190 and closing back up around 160, it should close around 180 if it is a 190 stat.

Thats just your thermostat cycling, I started seeing that after installing a new tstat, kinda makes you nervous at first but nothing to worry about. :c: