Air in oil

When I change my oil, I notice quite a bit of air bubbles as the old oil drains. when peridocally checking oil on dip stick, there is at times a very tiny air bubble on dip stick. never saw this before ??

 

I guess that is why I am concerned. had lots of coolant in oil a few months ago had inframe done. so far only 20,000 miles on inframe. dont see the white milky look on my filler cap like before inframe & so far no noticeable coolant loss, unless it is a very small amount. could, what looks to me like air bubbles be coolant in the oil? it is either air or something else. I never saw so many bubbles when changing oil. though after old oil is out in oil pan after a lil while the bubbles dissapear, if that means anything, BUT, when I take from 15 gal pan & pour into oil jugs when filled the bubbles reappear on top again, then dissappear after a lil while, just like when first draning into pan. with oil & coolant mixed, would the coolant go to the top or is it heavier than the oil & go to the bottom? I am less concerned about air if it is air than coolant. thanks for the opinions.

 

Well for over 11 years I would add lucas in every oil change. never saw bubbles in oil. the last oil changes since inframe, have NOT used lucas, got bubbles. as far as dip stick lengh, could be. shop had identical junk truck out back that we used parts off of. though it was identical. my mechanic said it is air bubbles. if it is air, I am not as concerned if it were coolant, but how would air... why would air be in oil ? but then I am thinking after I drain old oil & the bubbles dissapear, why or how would they reappear when I re pour oil into smaller jugs? if it were air, would not it escape & be gone? dont make sense to me why or how air would incorporate itself over & over in the oil after it is out of truck. taking 2 gallon jugs & filling one with old oil & poring back & forth from 1 jug to the other, I get bubbles. I may try a test & take some of my car's old oil & mix with small amount of coolant & shake up & see if I can duplicate the bubbles. I think it could still be coolant left in from inframe.

 

Crankcase breather, NOW that's something I never thought of. thank you!

 

I just changed my oil on my car yesterday. got lot's of bubbles. I think I am just paranoid after spending so much & having so much work done on truck, that if I smell, see, or hear anything out of the ordinary, I think there may be a problem. sorry for the waste of time. thanks for all who gave opinions. after going over 11 years & never having a breakdown on the road, I just wanted to keep it that way.