To try and keep a long story short, I have a 1985 300sd and a 1984 300sd. The 1984 starts up fine. The 1985 will not start unless you cycle the glow plugs at least 2 times and I am talking full time even after the glow plug light goes out I watch the dome light brighten then crank. I have replaced the glow plugs, and noticed that they were hard to remove. Could carbon build up cause this problem? Note both cars have about the same mileage 325,000. I did not have a reamer, but if I did use a reamer, where would the crud fall? Suggestions and comments welcome. Thanks