LB7-smoking when at idle

[locoduck]

i have a 2003 2500hd with 130k. When the truck is hot and at idle there is excessive smoke. Checked the fuel pressure and injector pressure and all is reading good. Could the injectors be leaking in the chamber

[Kennedy]

Unfortunately this is often the beginning signs of injector issues on the horizon.

[madmatt]

^^^^^^ most possible cause although cracked pistons and blown headgaskets can do the same thing but usually have other symptoms.

[Mark Rinker]

I have replaced 4 sets of (warranty) injectors on 3 different LB7 trucks. On my latest, which was a very 'light smoker' (and out of warranty...), I started running 1qt of cheap ATF per tankful of #2, about every other, or every third tankful.

The smoking subsides. Mileage is still good. Power is still good. Oil not diluted. You can buy ALOT of convience store ATF for the cost of a set of injectors...like 1500 quarts worth!

Not a cure for heavy white smoke, oil dilution, or an engine that is running rough or has developed an audible fuel knock, but if its still light and you aren't 'making oil' on the dipstick yet - you might give it a try.

Your LB7 should still be under warranty, but you might get more miles out of this set this way, or until you make plans to have the truck off the road for a few days, some dealerships take as much as 2-3days for injector jobs.

[03silverchevy]

New to the forum- I took my 2003 2500HD into the dealer to have balance test done- excessive blue/gray smoke at idle, no fuel in oil, smells like diesel out the tailpipe. The balance test was within specs, but 3 injectors showed a difference. Dealer said it would be $1600 to replace the 3- I have 163000 mi on the truck, and have Banks Big head wastegate and Banks Monster exhaust- they said i was running a programmer and it would not be covered under the injector TSB. Not sure what to do! :eek: