5.9 not warming up

[LoganBush]

Hey guys. New to the site and looking for some help and advice. I replaced the thermostat on my 1998 5.9 because the temp. gauge was only showing up to about 140*. After replacing thermostat, it still does not warm up enough. Any suggestions on what the cause could be would be great.

 

[Bigtman07]

After replacing the t-stat what does it get up to now?? Same thing?? I don't want to sound insulting but you sure you got it installed right? You very possible could have had a bad one given to you. God know how long those things sit on the shelf.

One thing to test the t-stat is start the truck and let it run and stand up but the radiator hose. hold onto the one that goes in at the right. Should be cold at first and after a while it should suddenly turn hot. if it seems to warm slowly at the same temp as the one on the left then t-stat needs changed. It's stuck open. Try that and let us know how it works out.

Welcome btw! lol

 

[KGBIGCOUNTRY]

Im thinking stuck open also or the incorrect one was given.