Here's a strange one. My engine has 165k on it so I expect some smoke on start up. It goes rite away. Here's the weird thing. While in line for a car show the gas was real low. It started blowing blue smoke. While backing in 30 min later the cloud was thick and it ran out of gas. I put 2 gallons in it enough to make it to a gas station and good god it was bellowing out the blue smoke. I filled it up and as strangely as it started it quit. I can't explane it any one got a guess.