i have a 2006 5.9 cummins with 218000 miles on it, im not the original owner so im not sure what work has previouly been done to it, but here are the symptoms. When i start it in the morning ( even when its 70 degrees), it has a little white smoke and a slight miss for the first 3-5 min, then it clears up. It always starts quick and has good power. I did an injector kill test and when its cold the number 1 cylinder only had a very slight difference in sound, unlike cylinder 2-6, after the truck is warm, number 1 kill test seems normal. Also, when cold and the kill test is done on number 1 the white smoke immediatley disappears. I thought maybe i had a bad injector on the number 1 cylinder so i switched number 1 and number 2 injector. I did the kill test again while cold and got the same exact results and the white smoke stayed with cylinder number 1. I did a cylinder contribution test and results 1-6 were the following 99, 102, 107, 97, 98, 106. Coolant and oil levels seems to be normal. What do you think the issue could be, ( FCA, injectors, rings, pistons)? I do have some blow by, but does not seem to be using oil.

 

If one injector goes bad, odds are that the rest are not far behind. So you should replace all 6 injectors with new feed tubes. Your contribution test shows that some injectors are not within spec. 10% range is not ideal. Does the smoke smell like diesel?

 

I'm way late to this.. but my truck has the same symptoms, you ever figure out what was causing it? Thanks