Chevrolet Repair: Truck blowing smoke and knocking

Question
Hi, i have a 2003 Chevy Silverado 2500HD Duramax Diesel that is blowing smoke, which looks like black smoke, and it knocks. Could it be the turbo or injector? Looking forward to hearing from you, thanks!

Answer
Hi John,
When was the oil changed last. It could be a number if things.it could be the orings on the injectors causing fuel to contaminate the oil. Also the fuel pump timing may be off. Your best bet would be to have it hooked up to diagnostic machine. I wish I could be of more help, but there is too many possibilities that would cost so much to replace. If you do have it diagnosed I can help you from there. Thank you for your question and please feel free to ask me anything else.