Does the engine oil lose its properties if it is drained in the pan and returned back

RZAmnt
Sun, 26 Nov 2017 18:48:23 +0000
Maintenance/Repairs

Is the synthetic engine oil hygroscopic (like brake fluid, or AC compessor oil)? Does the oil lose its properties if it is drained in the pan and returned in engine again an hour later?
Yesterday I had to drain the engine oil and then put it back into the car, because my car’s drain plug had a leak and I had to replace the washer. I drained the oil in a plastic oil pan. The oil stayed for about an hour in the drain pan covered with a piece of paper to prevent some dust to get into the oil. You understand that the drain pan in which the oil has been left for an hour is not hermetically sealed and the oil has been in contact with the air all the time. Before I pour the oil into the engine I filtered it, so the procedure stretched so long.
Тoday I checked the oil level and noticed some yellow thing on the dipstick that looks like a mayonnaise? I suppose this is moisture / condensation in the oil? Is it yesterday’s draining and returning oil a cause?
The oil was replaced a full synthetic oil a week ago, and after that I’d noticed the leak that I successfully eliminated yesterday!

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