Hey guys doing my water pump in a bit here and was gonna do thermostat for the heck of it. Noticed stock temp is 195?! Would like a cooler opening because truck take like half an hour to warm up in winter. -40°C here sometimes. Wondering what will come of using the 180F° thermostat? Thx.

 

If you want it to run warmer you want the one that opens later, the stock 195 would be it. These engines are very particular about their tstats, I would only use a Motorcraft tstat as others have ran in to issues with aftermarket ones.

It will never warm up if the thermostat opens at 180, and there ain’t much heat in the cab at that temp lol.

 

It will never warm up if the thermostat opens at 180, and there ain’t much heat in the cab at that temp lol.[/QUOTE]
Darn I was hoping 180° coolant running through the block would help it heat up on cold days

 

Darn I was hoping 180° coolant running through the block would help it heat up on cold days[/QUOTE]

The coolant in the block will get to 180, but when that tstat opens all the cold coolant in the rad will drop it below 180. You’ll never get warmer than that. 180 is gas job temp, it’s just too cold for these engines. And too cold for you in the cab.

When it opens at 195, mine will drop down to 180ish, as these trucks have big cooling systems. Tstat closes and back to 195. It helps to have the grille covered as well. My winter front covers the entire grille.

 

FWIW my IDI seems to run best (most power and best fuel economy) at 210-220. Which is pretty hard to sustain those temperatures with 100% factory cooling system (it's just too good at its job), and practically impossible with a 180F thermostat.

I vote for a factory Motorcraft 190/195/whatever thermostat.

 

Thinking back 192 rings a bell, but either way we’re splitting hairs. Iirc, guys were having flow issues with aftermarket tstats. Glow plugs and thermostats, stick with Motorcraft lol

 

The coolant in the block will get to 180, but when that tstat opens all the cold coolant in the rad will drop it below 180. You’ll never get warmer than that. 180 is gas job temp, it’s just too cold for these engines. And too cold for you in the cab.

When it opens at 195, mine will drop down to 180ish, as these trucks have big cooling systems. Tstat closes and back to 195. It helps to have the grille covered as well. My winter front covers the entire grille.[/QUOTE] oh ya I have the diesel. Takes forever to warm up it feels like. Gonna do a coolant flush and get a filter, I’ve got a mishimoto rad for it