Something in my coolant.

[444 ci]

is your truck loseing oil ?if it is its your oil cooler.

 

[Black 02]

Got a sample and had it tested. It's not diesel.

Sorry Jeff, I missed the tested for fuel part. Symptoms sound just like mine when the cups were leaking.

Good Luck!

 

[Southmike]

here is a PDF on how to do it,,

and pics here
http://powerstrokenation.com/forums/showthread.php?t=60968

 

[PowerstrokeJunkie]

If it's the cooler, oil usually moves into the coolant as the oil is normally under more pressure. However at idle when hot the oil could drop below ~16psi which is what the cap is vented to. In that picture it looks like oil particles seperating out.