I have an 06 3500 with 210k. I had everything showing that I had an injector going out. Crap load of white smoke at start up, excessive blow by. Did an injector cut out and found #6 was bad. Bought 6 new injectors and just replaced them and all feeder tubes. Truck is still missing and white smoke at start up. Its not coolant all you can smell in fuel. Any ideas and anything that can help would be amazing. Thanks. A littke more info that might help. I just started the truck cold and ran a temp gun across the exhaust manifold. All cylinders are warming evenly except #6. All cylinders were about 125 to 130 and #6 was at 80.

 

Probably damaged #6 piston. Run a compression test to verify.

 

Thanks for the input. That is about the only thing I can think of and Im dreading what I will find.