Ok, so I bought this car with about 174k miles. It had a knocking noise when I bought it, it turned out being one of the idlers. My mechanic fixed it, and changed the timing belt. I added about 3k miles to it so far, had fun with it. After a long drive, it began making a rattling/scraping noise. I cant figure out what it is. The sound comes from the right camshaft area. Let me know what you guys think it could be. Thanks in advance.