Another question do you guys! I just replaced my thermostat on my 00 f250 v10, I made sure I put the stat in the proper way. Before I started I drained the resivore and the radiator. The coolant was pretty dark, so I drained quite a bit. I replaced 4 gallons of fresh 50/50 pre mixed peak anti freeze. Now I must have alot of air in the system? My top hose is hot! Bottom hose is cold, and so is the coolant in the resivore? And my temp*is getting pretty hot on my guage. Any ideas?

It is blowing hot air with the heater on hi..........

 

I know on my 7.3, when doing any work that requires me to drain the coolant, that the temp will go skyhigh, then immediately come down, signaling that the thermostat opened, and all the air escaped into the reservoir. From there, refill the reservoir to the proper level.

It is scary when it happens, and takes 10-15 minutes of driving to get it hot enough. The guage will stay cold until it skyrockets to the hot end. then comes down and equalizes. Done it many times now, but everytime it scares me. As soon as i see it skyrocket, I pull over and wait for it to level out, then get out and add more coolant. Just make sure to open the reservoir SLOWLY to let the pressure out. As the pressure is let out, the coolant level will rise, then fall. Add more to get it to the normal level.

I had to drive it to get it hot enough to push the air around. once the air moved the coolant from the heads hit the thermo and sky rocketed the temp.

When you go for your drive to purge the air, take an extra gallon of coolant with you in the cab.

The only other thing I can think is that you got a bad thermostat, and it is not opening. what temp of thermo did you get. My PSD uses the 192 degree one.

 

The one I removed was a 185, the one I got to replace it is a 195. My guage usually sat just above the C

Now it sits about half way up or a lil more....and it stays there.
How long did you have to drive your truck before the air moved? I drove mine at least a half hour last nite.
Another thing i noticed.......I dont see the coolant moving at all in the resivore?

 

Excursion forum tech folder has a coolant burp process. IMO its extra steps. When I replaced my T-stat last year I kept the reservoir cap open which is essentially the rad cap with the truck on and filled it. The fan will cycle and thermostat should open burping the system. It may take some time in the driveway though. Keep the heater off but the temp on high.

Do you have a scan gauge or a ultra gauge? I would suggest investing in one so you know the exact temps.