Well this happens and don't know why , i go to open up the oil cap and under it theres the milky substance,
some people tell me that iv blow a head gasket but i don't think thats the case here, my oil is fine , my dip stick is clean ,
if i go to change out my oil its black and not milky, why is this just happening on the lower part of my oil cap ,
could it be that moisture is getting in some where . My truck is a 94 inline 6er

 

It's normal. As long as your oil is clear. It's just atmospheric condensation due to temperature changes.

 

thanks for that jim, i was abit worried about it but not no more .

 

very common at cooler times of the year