I have a 380SEL w/ only 51k miles. It is a 1983 model and still has the "single timing chain" Now, I hear some sort of rattling noise when I start the car. It doesnt go away at all no matter what you do, Rev it up shut and turn off, etc... It sound like soda cans rustling on the street but it isnt loud at all. You can only hear it when it is extremely quiet around. Im worrying that it is the chain and it will break on me. What shout I do?? Is it the chain making the noise???