White smoke from tailpipe after idle

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johnrburke2

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I am noticing some white smoke from my tailpipe after the truck idles for a period of time. For example, if I drive to work, how about of my truck and leave it running. After a few minutes white smoke will come out of the exhaust. When I start driving again, it blows some white smoke for a half mile or so. Other than that, there is sometimes white smoke when idling at a red light and shortly after take off. I do not notice it while driving.

Any thoughts on where to look first?

2003 Silverado 2500hd, Duramax lb7

All stock except tires/rims & 3" lift


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J

johnrburke2

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2003 Silverado 2500hd, Duramax lb7

All stock except tires/rims & 3" lift
baf5c0fe17d19e87d87ffa882959cfba.jpg


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J

johnrburke2

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zakkb787 said:
It’s an lb7 so culprit could very likely be injectors. Know the history on them? Balance rates?
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I have the full history records from the previous owner. He took good care of the truck and said he replaced the injectors twice. Is there a way I can tell if they need to be replaced again?

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DAVe3283

DAVe3283

Heavy & Slow
Sep 3, 2009
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johnrburke2 said:
I have the full history records from the previous owner. He took good care of the truck and said he replaced the injectors twice. Is there a way I can tell if they need to be replaced again?

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Click to expand...
What you're describing (white smoke when idling) is one of the signs it needs injectors again. Strong diesel smell from the exhaust, harder starting, and fuel in the crankcase are other signs your injectors might be bad. Any one of those could be bad injectors, and most trucks never exhibit all of the signs. Especially fuel in the crankcase, that has become pretty rare as modern injectors don't fail that way anymore.

If you have access to a scan tool, read your balance rates and main fuel rate. You'll want to see a main fuel rate of 8 mm³ or higher at idle and balance rates less than ±4 mm³ in park, as a general ballpark. If your main fuel rate is low, that means your injectors are leaking, another sign they need replaced.
 
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johnrburke2

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Y'all are great. I appreciate the feedback. Is there anything else to watch for or is it most certain injectors?

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Capt. Jim

Capt. Jim

My other ride has 3412E's
Mar 23, 2019
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I also had that same issue years ago with my '03 LB7. This was 100k miles after having injectors replaced under warranty. Fortunately, my injectors were still under extended warranty. Had them replaced and no more smoke. Good luck with yours.
 
zakkb787

zakkb787

<that’s not me...
Sep 29, 2014
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Granite Falls NC
If it does need injectors. Do not go cheap. Avoid Pensacola or many of the others. Only get factory Bosch remans. Not refurbished. Lincoln diesel is just about the only place anyone here will recommend.
 
BlkMax

BlkMax

Member
Sep 1, 2008
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Wasilla, AK
Lincoln Diesel Specialties has the best prices and quality I've seen on LB7 injectors (either stock, oversize, or SAC style). I went with the SAC's on my last install.
 
Brent@LDS

Brent@LDS

Vendor
Vendor/Sponsor
Aug 23, 2011
651
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Wisconsin
Sounds like injectors, when was the last time a set of injectors were put in the truck? We will get you taken care of here at LDS if it comes to that.
 
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johnrburke2

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I can review the files that I got from the previous owner. I have had the truck for about 18 months. So it was longer than that :) I think it is time for new injectors. If it does not go against forum policy, please let me know where I can go to look at your injectors And which ones would best.

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johnrburke2

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DAVe3283 said:
What you're describing (white smoke when idling) is one of the signs it needs injectors again. Strong diesel smell from the exhaust, harder starting, and fuel in the crankcase are other signs your injectors might be bad. Any one of those could be bad injectors, and most trucks never exhibit all of the signs. Especially fuel in the crankcase, that has become pretty rare as modern injectors don't fail that way anymore.

If you have access to a scan tool, read your balance rates and main fuel rate. You'll want to see a main fuel rate of 8 mm³ or higher at idle and balance rates less than ±4 mm³ in park, as a general ballpark. If your main fuel rate is low, that means your injectors are leaking, another sign they need replaced.
Click to expand...
OEM Injectors didn't put an end to the white smoke :( I still get a lot of white smoke after the car is idling for a while. There is also a small amount when stopping at red lights.

Any thoughts?

This picture is of me hitting the gas after the car has idled for about 8 minutes.
f8db45c777bbf9e246ea7b9823c5e58f.jpg


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