Hmm, is your upper radiator hose hard after sitting all night? Could be a head gasket. Also, look at your waterpump...it could be going....although, i think it would be leaving something on the ground. Have you tried to clean your overflow tank cap? Check your oil for antifreeze too.
2016 GMC Sierra 2500HD Denali
Extang Blackmax Tonneau
Weathertech floor mats and mud flaps
X-pel clear bra
295/60-20 Toyo Open Country A/T II
SOLD 2004 GMC Sierra LB7