I removed my oil cap and there was a milky beige film on the inside. The dipstick oil was black. Car has 67K and it has been 7K since last service. Is this normal or does it indicate a problem, e.g. oil and water mixing? Thanks for your comments!

 

I heard somewhere that this is from humidity and is normal. But if the oil on the dipstick looks milky then you've got a coolant leak.