Hello--I'm new to the site. My 95 F350 7.3 will not get warm in cold weather for some reason. That means the temp gauge barely moves, regardless of how long I drive it--and more importantly, the heater doesn't blow hot air like it used to...I do have a leather cover I use on the grill, but I can't tell that it helps at all. Any suggestions on the problem? Thanks!

 

Ever replace the thermostat?

 

Nope. I have done that years ago on gas engine, but I know little to nothing about how my diesel runs...It's been so trouble free for 15 years that I haven't had to learn until now. I assume that is a relatively simple thing then? Thanks so much for the Diesel 101 help...

 

My guess is that you need one. Pretty simple to do

 

I would agree with the Tstat replacement...