I just replaced a head gasket on my 3.0. I set the valves, replaced manifold gasket, replaced everything back into original position. Started up engine and was running good. Left the valve cover off to check the valve adjustment and realized after 30-45 seconds water started to come up thru the push rods and onto the rocker arm. Took everything back off and recheck. Everything appears good. Any suggestion why water would be getting in the oil. Thanks.