smokes only at idle on 2004 Chevrolet Silverado 3500

I have white smoke out the exhaust only at idle. I checked antifreeze level and I know that is not burning that.

Asked by for the 2004 Chevrolet Silverado 3500
you wont notice coolant loss when burning. it would take a while before you noticed any loss. i would have the cylinders checked for leak down. i believe you will find a head gasket or cracked head issue.