I just picked up a used civic for a daily driver. This evening I changed the valve cover gasket. I noticed that there is water pooled in the head. It's not that milky crap, so it's not mixing, it's just sitting there. I only noticed it when I happened to glance down at an odd angle and the oil reflection was greenish. There isn't any water in the oil, it looks completely normal on the dipstick, and when I drained it.

Coolant looks good and motor seems to run great.

Is this something I should be worried about? Bad head gasket? I plan on doing a compression test tomorrow.

 

In winter time you will get condensation under the oil cap/cover. It just means that the engine was not run long enough to burn the water vapor off and makes a whitish film (water and oil). This is of course assuming you do not have a head gasket issue...

 

^^I've never heard of condensation under the valve cover, that is interesting. If I were the OP I would check the coolant to see if there is oil mixture in there as well as do an oil change and take a look at the rest of the oil.

 

Yep, not much of a problem. You usually see it on short run trips wherein the engine has not had enough time to burn it off. Normally happens in cold weather.

 

I drained the oil, no water in it. I pulled the oil pan to replace the gasket, and there was no water in the pan. The coolant looks brand new so I'm not sure about that.

I was wondering about condensation, but it seemed to have a slight greenish tint when I wicked it up in a paper towel. Maybe it picked up the tint from the oil.

 

hmm well if it had a greenish tint it might be coolant but its probably okay because if the oil looked fine and the coolant looked fine I would think you are okay right now. Just keep an eye on it.