04’ Lb7 smokes a lot at idle

Inkram

New member
Sep 8, 2021
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My 04’ smokes a lot at idle. It’s not always consistent, sometimes it will smoke a lot and sometimes it is just a very thin haze. Truck dose run perfectly with no symptoms of anything wrong. In the past two years I have installed a new turbo, new injectors, and new fuel filter housing. Oil change, air filter and fuel filter are changed twice a year regardless of how much I drive it. Any ideas of what it could be??
 

NevadaLLY

Adam B
Feb 24, 2019
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Reno, NV
My 04’ smokes a lot at idle. It’s not always consistent, sometimes it will smoke a lot and sometimes it is just a very thin haze. Truck dose run perfectly with no symptoms of anything wrong. In the past two years I have installed a new turbo, new injectors, and new fuel filter housing. Oil change, air filter and fuel filter are changed twice a year regardless of how much I drive it. Any ideas of what it could be??
Fill out your sig so we know what we’re looking at. Any tuning? If stock, likely an injector issue. Have you checked balance rates?
 

Inkram

New member
Sep 8, 2021
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What brand injectors did you install? Is this a new symptom or has it been going on for awhile?
I don’t remember what brand of injectors I had put in, they are stock replacements. The smoke started before the new injectors and hasn’t changed.
 

2004LB7

Well-known member
Dec 15, 2010
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if pensacola rings a bell then it's time for new injectors. if you got them from a reputable vendor then perhaps installation contamination on the new injectors.

and as mentioned above, get us the balance rates and main fuel rate. Baro, MAF, desired and actual fuel pressure would be good too. and if you can, maybe even do a compression test
 

2004LB7

Well-known member
Dec 15, 2010
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sounds like a leaking injector. may be able to find it by pulling the glow plugs, disabling the injectors and cranking it over to see if any fuel comes out the glow plug holes
 

Inkram

New member
Sep 8, 2021
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This problem started before the new injectors. New injectors didn’t solve the smoke. Some days it’s good and some it looks like I’m on fire
 

sneaky98gt

Member
Nov 5, 2013
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Sounds exactly like a bad LB7 injector, or exactly as my bad LB7 injector anyway.

If you're positive that it smells like diesel, there's only a couple other possibilities. You could have a cylinder low on compression, but then you'd likely have other symptoms (down on power, fuel mileage, etc.). It could also be a fuel pressure problem (either CP3, regulator, or tuning), but again there would probably be other symptoms (rough idle, hard to start, etc.).

As mentioned already, some simple OBD2 diagnostic values would help narrow it down a lot (balance rates, main fuel rate, fuel pressure). If you don't have a scanner, you could probably get Advance or Autozone to pull them for you. Needs to be done with the truck at operating temp, in park, at idle, and with the A/C off.
 

Inkram

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Sep 8, 2021
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Yeah I’m gonna have to talk to my mechanic. I was told by my brothers Diesel mechanic that it very well could be bad cups, but I guess you can’t really test for that
 

Bdsankey

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Feb 1, 2018
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I would agree with other comments, I think it may be time for a set of injectors. Depending on the brand I've seen them be bad out of the box, fail in 1-5 months, or fail a year later as it's simply unknown with some of the crap companies. There are quite a few good companies out there, just have to know which ones to pick.
 

ZeroGravity58

Well-known member
Mar 23, 2008
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I'm just venting but I see this on here and on Facebook groups. Everyone always cheaps out and buys the lowest price injectors and then are always surprised when they have to do them again in 6 months. With all the info on the internet has no one learned anything?
 
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TheBac

Why do I keep doing this?
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Apr 19, 2008
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I'm just venting but I see this on here and on Facebook groups. Everyone always cheaps out and buys the lowest price injectors and then are always surprised when they have to do them again in 6 months. With all the info on the internet has no one learned anything?
Do you really want (or need) an answer to that? :LOL:
 

GO0BER

New member
Mar 10, 2022
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Reviving an old thread instead of creating a new one.. I have been trying to determine if my injectors are going bad (I am new to diesels (Only had my current truck a little over a year).

I have an 04 silverado 2500 with the lb7. I am getting white smoke at idle.. but even more when in reverse/drive. Reverse is the worst offender in terms of smoke volume.. Drive is hit or miss.. some days its pretty bad (at traffic lights and such) and other days not so bad. In neutral/park its hit or miss.

The smell is pretty distinctly diesel, no fuel in oil and no other symptoms (No power loss, no rough idle, no long cranking to start, etc). I did recently replace the fuel pressure regulator (I forget what its actually called.. replaced it just after Christmas)

I had access to a scanner for about 15 minutes the other day to check for balance rates and such (Are there any decent scanners in the sub $500 category? I got to use a snap on... but I don't have the money to buy one)

Here are a few videos I was able to take to get the data I see people requesting here:

Vid 1:
Source: https://youtu.be/YKNauC7lrqg

Vid 2:
Source: https://youtu.be/n3gSynK2B6M

Vid 3:
Source: https://youtu.be/1gulnw2WW4g

Vid 4:
Source: https://youtu.be/RG7Et7rG82c


While checking for these values the truck was 'cold' and only got to run about 10 minutes, not sure how much that hurts/helps the data.

Balance rates while in park:
0 across all cylinders

Balance rates in reverse but not moving:
cyl 1: 1.9
cyl 2: 1.2
cyl 3: 1.8
cyl 4. 0.5
cyl 5: -3.1
cyl 6 0.5
cyl 7: 1.5
cyl 8: -2.5

CMDS in miliseconds
inj1: 0.38
inj2: 0.29
inj3: 0.28
inj4: 0.29
inj5: 0.35
inj6: 0.40
inj7: 0.32
Inj8: 0.35

fuel rail pressure desired/actual both at 40 MPa

I assume this means I need new injectors since I dont see any values that are way off? Assuming this to be true, are BOSCH still the best factory replacements?

EDIT: forgot to add the truck is at 190k miles, engine is ~170k miles.. it was replaced when the truck was ~20k miles
 
Last edited:

Ryans

New member
Mar 13, 2022
12
2
3
Reviving an old thread instead of creating a new one.. I have been trying to determine if my injectors are going bad (I am new to diesels (Only had my current truck a little over a year).

I have an 04 silverado 2500 with the lb7. I am getting white smoke at idle.. but even more when in reverse/drive. Reverse is the worst offender in terms of smoke volume.. Drive is hit or miss.. some days its pretty bad (at traffic lights and such) and other days not so bad. In neutral/park its hit or miss.

The smell is pretty distinctly diesel, no fuel in oil and no other symptoms (No power loss, no rough idle, no long cranking to start, etc). I did recently replace the fuel pressure regulator (I forget what its actually called.. replaced it just after Christmas)

I had access to a scanner for about 15 minutes the other day to check for balance rates and such (Are there any decent scanners in the sub $500 category? I got to use a snap on... but I don't have the money to buy one)

Here are a few videos I was able to take to get the data I see people requesting here:

Vid 1:
Source: https://youtu.be/YKNauC7lrqg

Vid 2:
Source: https://youtu.be/n3gSynK2B6M

Vid 3:
Source: https://youtu.be/1gulnw2WW4g

Vid 4:
Source: https://youtu.be/RG7Et7rG82c


While checking for these values the truck was 'cold' and only got to run about 10 minutes, not sure how much that hurts/helps the data.

Balance rates while in park:
0 across all cylinders

Balance rates in reverse but not moving:
cyl 1: 1.9
cyl 2: 1.2
cyl 3: 1.8
cyl 4. 0.5
cyl 5: -3.1
cyl 6 0.5
cyl 7: 1.5
cyl 8: -2.5

CMDS in miliseconds
inj1: 0.38
inj2: 0.29
inj3: 0.28
inj4: 0.29
inj5: 0.35
inj6: 0.40
inj7: 0.32
Inj8: 0.35

fuel rail pressure desired/actual both at 40 MPa

I assume this means I need new injectors since I dont see any values that are way off? Assuming this to be true, are BOSCH still the best factory replacements?

EDIT: forgot to add the truck is at 190k miles, engine is ~170k miles.. it was replaced when the truck was ~20k miles
I am absolutely not an expert. There is guys here who are extremely knowledgeable at this and I am not that guy. But doing my research before i bought injectors (and botched my install) I thought the injectors needed to read around 2. Looks like yours are in a wide range, hence the smoke I assume. But I am not an expert. From my experience dont cheap out do the cups too!! Lol.