Smokey Car
Could be a couple of things.
1) Could be gas not oil. Not likely because it doesn't usually come and go like you described, but its an alternative. Usually too rich gas will be white looking smoke while oil is bluish and they smell different.
2) Your getting oil into the combustion chamber somehow.
2a) It could be thru the rings, your cylinder rings don't have oil injected into them under pressure, rather the oil is thrown about inside the engine coating the walls, so you could be pulling oil past your rings, and still have good oil pressure.
2b) Could be your valve guides. There are little umbrellas that slip over the top of your valve stems to keep oil from flowing down the valve stem into the cylinder. They get brittle and break sometimes allowing oil into the cylinder.
What I'd suggets is start with the easy stuff and work toward the harder stuff.
1) Make sure it isn't too much gas. Make sure your chock is open and staying open (wire it open if need be). If your choke was flapping, it could account for the intermittent behaviour, but then I'd think youd feel the power change. I don't think this is it, but I am not there looking at it. So, might as well make sure.
2) If it is oil, the valve guide seals can be replaced without pulling the heads. You need a spring compressor and an air compressor if I remember right. You screw an adapter into the spark plug hole, turn piston for that cylinder to tdc, and pump the cylinder full of compressed air to hold the valves shut. Then you compress the springs, remove the retainers, replaces the seal (just slides on) and put the spings and retainers back on. Even if you have to pay someone this is cheaper than the rings.
3) If you get to here, the only other entrance for oil is your rings (well theres the cracked wall option but I am gonna ignore it). Before you tear the engine down to fix this, try some of the engine cleaner products. Sometimes the rings are just gunked up, and cant seal. Again, try the cheap answeres first.
If that doesn't work, ask yourself how bad the smoke botheres you
If you just can't stand it, rebuild the engine. If your gonna tear it down to do the rings, might as well do the whole job (imho). That said you CAN just pull the heads and oil pan and replaces the rings with the block still in the car. Not something I'd do, but it can be done.
Because you say it is intermittent, I believe your gonna find its the valve guide seals, but then thats hoping on my part for you to save you cash and work.
Best of luck.
