Blue Smoke At Idle
 

The last two weeks my truck has been blowing blue smoke when I'm stopped at stop lights (at least this is when I notice it). Basically it will blow clouds of blue smoke for a few seconds, and then it will stop for 15 or 20 seconds. then it will start smoking again. I can not see or smell any diesel in the oil. So is the general consensus I have an injector going bad? Could this be caused by bad fuel? The truck still runs great and I am getting good MPG.

sounds like injectors, take off any programmers you may have and take it to the dealer, if they dont change them, take it to another dealer

You could also find somebody in you area with a techII, predator, quad stealth II, PPE, EFI Live to check the balance rates. if you really want to try some ideas throw in some 2 stroke oil when u fill up about one oz to one gallon ratio.

x2....exactly.

The first set I had that went bad was netting 21.7 mpg. White smoke of course, but.........

Any updates???:w2:

No, it still smokes, and I have been to busy to take everything off the truck to take it to the dealer. I might try to find a used predator to check my balance rates myself.

make sure to heck them when ect's are above 160* and they should be -/+4 in park at idle and -/+6 in drive at idle

I finally got around to check them.
Engine temp 172 F
Park --------- Drive
1 -4.03 --------- -4.5
2 0.2 --------- 2.74
3 -2.74 -------- -3.86
4 0.7 -------- -3.1
5 -1.74 -------- -3.42
6 0.18 -------- 0.97
7 -1.01 -------- -1.38
8 3.42 -------- 5.23

What does the mm stand for after the measurement?

Your #8 injector is still within spec but getting close to being out. BTW- dont check your balance rates in park. The figures will lie to you. The first thing you need to check here before spending a bunch of time and money on hard parts is to check your PCV system. If its plugged or restricted you will get smoke at idle.

Is it possible to do a PCV Reroute on the LB7? Might be a cheap fix to look into :humm:

I thought the LB7 didnt have a PCV System.. I could very possibly be wrong though.. lol that happens alot.

its just a vent that blows down on the side of the engine, i found mine when it blew diesel fuel all over the bottom of my truck and all over the boat

The LB7 uses an open PVC system while the LLY, LBZ and LMM use a closed system. Here's pics of the LB7 system.

Yep, all 3 of my LB7s that have had injector problems, got the nice anti-rust undercoating :argh:

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If it's still under the 200k warrenty for the injectors, dump a gallon of diesel into the crankcase and take it to the dealer.....:w2:

lol :lol88:

OK so I have been checking my balance rates on and off for the last week, and number 8 is now running between +8 and +12 in drive, number 1 is between +5.9 and +6.5 in drive. Will the dealer replace them?

take out an programmers and reprogram it back to stock and get to the dealer, they should replace them yous is an 02, and if it has less than 200k miles on it

Will they replace all 8 or just the bad one? What will they say about my exhaust, pyro and boost gages, and secondary fuel filters?

when i went i had exhaust pyro, boost and intake, they didnt say a thing, i didnt even have to sign anything, my truck was done in 4 days (should only be 8 hours)

they replaced all 8

Dealer said no go.
 

According to my dealer, GM will no longer replace injectors for just smoking. The numbers have to meet their criteria. Even if the injectors are failing, they have to be "defective" not just worn out, which is usually the problem. The fuel pressure is so high, they explained, that they're wearing out in about 50,000 miles. This does not qualify as a defect. Good luck.

Dont know that much about diesels yet but learning. How do i know if i have an LB7 or something different?

UpSince yours is a 2002 you have an lb7 unless it was changed at one point

As of yesterday I'm having the same problem as you my friend. :argh:

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Lb7 is the duramax engine made from 01-04.5