Oil Catch Moisture in Cold

[tmontague]

I Installed the DIY oil catch can posted on this forum, last summer. It has been working fine with no issues and I usually get about a teaspoon of oil at each OCI. In the past couple weeks the temperature had dropped (now around -20 w/ windchill in morning). My morning commute is about 85km one way moving about 80-100km/h for the duration of it.

I noticed the other morning that instead of seeing a small amount of oil in the catch (which it had a week earlier) I instead saw a very milky whitish/yellow looking film on the outside of about 80% of the can. I am assuming that this is moisture/water mixing with the little oil that was in there and it is frozen hence the sticking to the can.

I am wondering if anyone has any experience with this, or if you think this is anything to worry about?

I have a good understanding of the PCV venting and I am presuming that the condensation from the very cold start is venting out the PCV (just cleaned in 2k ago) and getting dropped in the catch with the oil already in there. I may attempt to empty the catch tonight and see if it is water and oil at room temperature. I rarely do any short trips in my car and I'm conscious to make sure my car gets up to operating temps to help evaporate the water within the engine. My daily commute is more then adequate to rid the engine of moisture.

[CTScott]

That is very normal. When the air is cool and the engine warm, the condensation in significant and you end up with a lot of that foamy white stuff in the catch can.

[tmontague]

Thanks for the input. I've been doing more research on it and I'll be emptying it every week or so just to make sure it doesn't crack if it freezes.

The only issue I've heard is a few rare reports of the oil/water mixture freezing and blocking PCV air flow which builds up pressure in the crankcase causing oil seals to go and leaking oil. So far the milky mixture seems to stick on sides of can so I don't think I'll have an issue with the can freezing up and blocking air flow.

CT do you think this is something I need to worry about? I drive my car every day and it is always being driven up to operating temps.

[tmontague]

Side note: 3 weeks ago I noticed oil leaking out of valve cover seal to the passenger side of engine. Although this could be due to blocked PCV air flow I highly doubt it as it wasn't freezing temps yet (~2 degrees C in mornings). When I checked Valve cover bolts they were loose on that area of the engine (don't worry I asked for a torque wrench for xmas this year) I obviously didn't tighten them enough when i checked the valve clearance last summer

[CTScott]

I don't think it is anything to worry about. The air that flows through there comes in through the intake, so there will always be moisture. As for freezing - Once the engine warms up, the stuff in the catch can should thaw very quickly. If you are really worried about it, move it over closer to above the exhaust manifold.

[tmontague]

Checked the catch last night after an hour and 15 commute home averaging 50km/h due to the snow. The catch was really warm from the engine heat so I am not worried about it freezing.

I expected to see the milky solution in the catch but it turned out to be a tiny amount of oil and nothing else. I am assuming any water in there was evaporated out due to the heat? Either way everything seems fine and ever since I cleaned my engine block and re torqued the valve cover bolts there has been no new oil on outside of engine block.