Duh, sorry.

 

so i changed my tstat and now the temp gauge goes up and down. you can see the engine get up to temp and you can tell when the tstat opens as the temp drops right back down and then slowly goes up again.

is this what's supposed to happen with new tstat or is this one opening too quickly?

 

air pockets working their way out. Should get more even later.

 

Mine is doing this too, but I'm already on my second thermostat and it's still doing it.

It was overheating, so I changed the thermostat. Next thermostat it was underheating so I changed it again. Current thermostat it's still underheating.

Any other suggestions?

 

Jama, how is your coolent level at this point with all the changes? Take one of your T stats and put it in a pot of water with a meat thermometer that is adjusted correctly. See when it opens, that will tell you if thats good or at least what temp the dam thing is really opening at. You need to calabrate the meat thermometer first by making sure it reads 212 when water comes to a rolling boil (thats at sea level). Temp change for diffrent elevations are well charted in most cookbooks or online. Put one in the truck that you know opens were you want (correct side up!) Now jack up the passenger side of your truck, put antifreeze in it. Start it up with radiator cap still off and let it run with the heat on for like fifteen min's add fluid as needed. Replace radiator cap WITH BRAND NEW GOOD QUALITY ONE! If that don't work you need someone with a bigger brain then mine Good Luck! Jeff.

 

Hmm mine has been like this for a long time to, but when i first got my truck the temp gauge never used to move so i replaced the t-stat and my temp sensor then the line moved up to the spot that the OP has a pic of.. so i thought it was just normal. I tested my old t-stat in a pot of water and it opened right at about 190* so i knew it was good but i already had the new one and just put it in. so i guess i got something to look into now

i was wondering why i havent seen very good gas mileage.