It is finally time to replace the head gasket on our 300E! It is at the point that it uses 1 quart to every 500 miles if driven at freeway speeds and leaves quite a mess under it. At slow speeds, the car can travel around 800 miles between quarts. I have a few questions for the experts at doing these. First, the car only has 130,000 miles on it, should I replace the timing chain and the engine valve guides? I plan to replace the valve seals but have a hard time believing that the valve guides are worn out at this mileage as this engine should have the updated guides. Any input would help.

Aaron