that's interesting - i assumed i had a head gasket failure- it's a 2000 ml430-- i'm using water and it's going to the engine- the milkshake look to the oil- also running rough at times, too.when it's hot- but when it's cold- it runs great....i just had to replace the serpentine belt because it was covered in oil- they said it was a oil pump or somethingvery close to where you put oil in....and the power steering pump is close there too..