Coolant spill into oil pan?
 

Hey guys,
This isn't a Cobalt, but a 2003 Cavalier with the 2.2 Ecotec (My kids car). I replaced the timing chain, tensioner and guides, head gasket and bolts, antifreeze and oil. Replaced and torqued everything per specification, started it up and ran like a champ! No external leaks or white smoke coming out of the exhaust. Just for kicks, I pulled the oil plug and drained some oil which appeared to be a light milky brown. Coolant? Here's the thing, when I changed the timing chain on my 2.4 Cobalt, I was warned to be careful with the bolts as they could fall down in the oil pan. When I pulled the timing chain cover, about a glassful of coolant spilled out. Could the coolant have gone down into the oil pan giving it the light milky brown color? The coolant level in the reservoir is still full, so do I just go ahead and change the oil and check again? Compression test showed approximately 182, 185, 185, and 190.
Thanks,
Jason

When you pulled the timing cover there should not have been any coolant in there. Did you try to find the source of the water? Possibly the water pump leaking internally into the block? Definitely keep an eye on the oil level/condition. The way I found out where my coolant leak was coming from was pulling the oil pan and pressurizing the coolant system. Then I could see exactly how the coolant was getting into the oil.

Just for shits and giggles, I decided to completely drain and change the oil. Ran the car and had my kid rev the motor while I watched for smoke. Yep. White smoke. Pushed it into the garage and drained the chocolate milk. I pulled the valve cover off and found milky oil residue around the pushrods. I haven't pulled the head off yet. My only thought is I didn't check the head for flatness the first time changing the head gasket which caused internal leaking.(rookie mistake) Can anyone give me clues as to what to look for? I suppose a cracked head is hard to detect?
Thanks,
Jason

Push rods? are you sure its an ecotec and not the old LN2 2200?

Oops. Sorry I meant rocker arms.

Ah yes. The milky oil pooling in the head and white residue on the valve cover sounds familiar. Before you take the head off, pressureize the cooling system up to 15-20psi and see where its leaking from. If you take it apart and nothing looks visually wrong, then youll never know what the problem was.