Took the car to have the oil changed through the dealership in which I purchased the car used with 43,900 miles. (have the 300,000 Valvoline warranty). They found the leak with a light? I took it to my mechanic knowing that the dealership would tear it apart, replace the casket and be done. My mechanic gave it a thorough going over. He found the Intake manifold to be so badly pitted that it had to be replaced, I've seen it. If I had taken this to the dealership they would not have found this problem and charged me a fortune only to be problematic in the future when the manifold pitted all the way through and/or cracked/leaked. I have been told that if a pressure check had been done when purchased (6 month prior) this may have indicated a problem and should have been fixed before it hit the lot for resale. I am so pissed off about this. Just outside my 12,000 mile extended warranty. GM Cares will hear about this one. It is understood that this new coolant that GM is using (pink/orang stuff) may be the problem. Getting rid of this stuff for sure.