I have a quick question regarding my car. I just recently got a new head, water pump, and radiator installed in my car. When I picked up the car the car had a light knocking noise. Maybe not so light. I asked the mechanic about it and he said that they put a treatment in my engine and the knocking should go away. I'm not so sure about that, and had my dad looked at it and he didn't think that was the case. I had a lot of white smoke coming out of the exhaust, but that went away after driving for a while. The mechanic seemed like he knew what he was talking about. What do you think?

I don't understand why any additive would cause knocking, but I guess you'll figure it out after about a tank of gas. Please let us know what happens. I'm sure that someday I'll have to replace my head.