Air bubbles on petrol engine dipstick ?

Question

I have a query about whether or not it is normal to see bubbles in the oil film on the end of the engine dipstick but mainly so along the length of the dipstick.

When I check the oil and the engine is completely cold, I cannot see any bubbles in the oil film or along the length of the dipstick, it is only once the engine has been running and I then check the dipstick that I can see them.

Is this normal even when the level on the dipstick is NOT above maximum and how do I distinguish between these bubbles and the foaming/frothing of the oil that occurs when the crankshaft is immersed in the sump oil because of there being too much oil ?

Answer 1

make sure that it isn't coolant instead of air , which would point to a blown head gasket.

Answer 2

Engine oil should be checked when the engine is at running temperature ie hot.

Answer 3

you would normally expect a degree of frothing/bubbling if there was an excess of oil but i've not heard of this otherwise.

I'm no expert i'd take it round to my garage if worried.

Answer 4

when the engine is cold any water will be at the bottom of the sump ,once you have started the engine it will mix with the oil .

I think you have got water in the oil ,sounds like head gasket or cylinder head problems .

good luck h

Answer 5

Yes it is not unusual. The crankshaft in the engine agitates the oil, and it picks up air. That is why some racing engines have a deaerator in the oiling system and a windage tray in the oil pan.  

Answer 6

Have you tried different oils?

Answer 7

Sounds like there is a hole somewhere.

Answer 8

its normal...nothing to worry about.