Hello, I have a 05 Malibu with a 2.2 ecotec in it. couple weeks ago I started hearing a tap from the valve cover. checked the oil and noticed milk in the oil. 1st I though it was a head gasket but I have 0 water in the crank case and after 2 weeks of watching while I work I have not lost a drop of fluid form coolent system. . its only in the valve cover. I replaced the water pump. as 1st I though it might be coming from there. did not help. replaced timing chain as it did need one anyways. tensioner was bad. on timing chain and drive chain. it did not help. the kicker is when I cold start the car everything is fine. after about 45 min of running it starts the knock again. look in there and water is in the valve cover. so I look and find out there is no pcv valve and the hose for the breather was plugges up. cleaned it out with same result. cold starts are good. but then will start to knock again. water still developing up there. every time I do anything I change the oil. then I find out about the little port on the intake manifold that is part of the pcv system. pull off intake and its plugged. put it togeather after a good cleaning and run the car. steam and a small stream of water comes out, runs good but again after about an hour I start getting a knock again. if it sits an hour after running it run great but then after a bit will start to knock again. I am at a dead end. don't understand why it would run great then start tapping after a short while. I run car without the valve cover off for a short time and oil was flowing good. I don't seem to have any moister in the valve cover anymore. any ideas please. I and ready to take a shotgun to the car. steam and water from the exhust is normal now. no steam and maybe a drop or 2 here and there.