i have smoke coming from the oil filler cap

[MASTER2009]

is this likely to be the head gasket

[tom hopkins]

i would say get a compression check done ,it could be damaged piston rings or maybe cylinder head or both

[mr rusty]

Whats the mileage? On a high mileage engine this is normal, and nothing much to be concerned about.

[xx marti xx]

if it is your head gasket,which I doubt, you will most likley have oil in your cooling water.This normally shows itself as a milky substance in your cooling system,this can also be accompanied by an increase in pressure in the cooling system,with the engine running try to squeeze a flexible radiator hose,if its really hard/solid its over pressured.As T.H suggests its more than likley piston rings.But as Mr R says it depends on the age/mileage and if there is not too much smoke dont worry !