If your Degas bottle cap has a white sticker on it still. That is the old style cap. And they tend to fail over time. New caps are $15 at your local ford dealer or you can get the am one for $5 at advance auto. Even if you have no signs of leakage around the cap its worth replacing. Fyi I'm not a Bill Hewett fan. But he is right about changing the cap. Just missed the boat on everything else.

 

Unless your truck is a SCREW, it won't have that valve.

 

That only applies to the '03 and '04 trucks. Appearantly the '05 and later truck all got 'em regardless of cab orientation. Also, Excursions have the coolant shut off valve.

 

Yea mine is an 04 6.0 with 180,000 miles with stock everything as far as the engine. Only thing Im running is an Edge chip on mild setting.

 

I guess I drive a SCREW. And my neighbor,,, he has a 2005 6.0l he also drives a SCREW.

 

I'm having the same issue now. My delta runs about 10 to 11 but it has gone up to 17-19 towing nothing for 2-3 seconds. No fogging of the windshield, and carpet is not wet. Puking is on the top of the degas and the bottom, and I have change the cap three times now. My coolant level is below the min level if the truck is warmed up the coolant line sets about 2 inches from the bottom of the degas bottle. Sorry the pictures are so big I could not figure out how to make them smaller.