--------------------------------------------------------------------------------

My Lexus is a 1998 SC400, 110,000 miles. Yesterday when I started it the engine ran ruff, had a metallic knocking and some blue smoke from the tail pipes. I lifted the hood and it appeared the knocking was coming from the top front of the engine. I shut it off and started it again, this time it ran fine. Could this be just a sticky lifter or the sign of worst things to come. Is there something I can put in the gas or oil to free up a sticky lifter, if thats the problem. Any help out there???