How to quickly test for a blown head gasket and what to do if it is.

The first model year was 2005 NOT 2007 for this W221 body style. And the oil had NO "Chocolate milk" appearance to it. Always do this check with a cold engine NEVER open the radiator cap when engine is HOT! 2007 Mercedes Benz S550 2005 2006 2007 2008 2009 2010 2011 2012 2013