'Bubbles' in the oil are not good. Usually, they're not air bubbles, but water droplets. When you see them, it's a sign that your oil is contaminated with water and needs to be changed. A more serious problem is how the bubbles got there. Quite likely, there's a leak between the system that circulates oil (to lubricate moving engine parts) and the system that circulates coolant- the water 'jacket'. Could be something relatively simple, like a blown head gasket, or something really ugly- like a cracked head or block.Hey, be thankful you're not dealing with the idiot invention of the century, the dual action fuel pump. That little gem pumped water for the cooling system and fuel for the engine, separated only by a thin rubber diaphragm. Get a leak in the diaphragm and it pumped fuel into the water jacket and coolant into the fuel system. Usually, the engine died from trying to burn water, before the fuel in the water jacket overheated and exploded.
Without seeing the bubbles it's hard to diagnose. Often times cheap oil additives can actually cause this.