It's weird that I have never once had my truck idle faster because of the cold. I don't get out much in the cold, but it was near freezing on many occasions two years ago when I was here in SC and I never saw it do that. This is also the first 7.3L I've owned.

 

Start with a new thermostat. They do go bad and fail open more often than not on these trucks. If you oil temp never goes above 140 or so, the truck is not reaching normal operation temp. Your fuel economy is greatly suffering as well.

Highly recommend either the IH or Dieselsite 203deg thermostat instead of the motorcraft 180deg one.

Its just 3 bolts to change it.

 

It's not so much the idle that rises (although it may, I just never looked) but rather more of hearing the idle sound change because the EBPV closes.

Did you gut your EBPV?

Stewart

 

Yeah it's gone now. I don't really notice any difference though.

 

Run it up into the 140s or whatever you are maxing out at and then grab the return hose to the radiator and see if you can tell if the tstat is popped open already. My 6.0 is running in the 160s-170s in 40-50F weather, so I checked and the tstat appears to be wide open, so new tstat going in next week.