Question for the mechanically inclined. My girlfriend has a 2010 Forester XT. Recently, it started smoking lightly and was a hard start. Autozone told her to add oil. She did and it was 2qts over for less than 24 hours. I did an oil change and it started smoking heavily. Took it to have the code run and timing on all four banks are over-advanced. Will over-advanced timing cause the car to smoke heavily? I'm thinking a timing belt should fix it. Any second opinions?