Well its fairly simple about the oil. Just check your oil levels daily in the morning. If you are not losing oil, then you are using the oil that was left in the intake from all the previous issues.
Secondly, please make sure that you're not using engine oil that is too thin for your car. You would burn too much that way as well. 5w40 or 5w50 should work fine. If you're living in an especially cold area, you might have to go down to 0w40/50. Going to 30 weight oil might not be the best move if your piston rings are too worn.
What did your mechanics say about the latent smoke issues that you have mentioned ?
Last edited by robertobaggio20; 11-25-2012 at 07:55 PM.