Hi
I have a 2001 Silverado 2500HD with a Duramax.(255,000 kms) In the past 10 months or so I have developed a mysterious coolant leak that has gotten slowly worse. I am guessing it is internal( head gasket or injector sleeves) but am wondering about symptoms. I am not getting any noticeable white smoke or bubbles in the cooling sytem. The injectors were changed 2 years/ 70,000 kms ago by a dealer with not much duramax experience. The system seems to be holding pressure fairly well as I can go back an hour after shutting it off and still have lots of pressure when I take the cap off. ANy suggestions? Thanks