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???

 

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

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