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Chevrolet Repair/Truck blowing smoke and knocking


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!

Hi John,
When was the oil changed last. It could be a number if 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.

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Jeff Brinkley


I have been working on Chevrolet and other makes for 30 years. I can answer almost all Mechanical, electrical, suspension, steering, runability, questions. I can not answer questions about body work.


I owned three auto repair shops. I also worked at Ford dealerships and Chevy dealerships.

Master ASE Certified

Awards and Honors
My shop in Champaign, IL was voted best Auto Repair Shop in Champaign, County in 2013.

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