i have a 04 lb7 and recently it started to smoke at idle and run rough when you have it in gear. put it in park or neutral and it runs just fine. but in drive or reverse it starts to idle rough. i have poured just about everythihng you can pour through it to make it stop (diesel clean, injector cleaner, 2 stroke oil) nothing works. before you say its my injectors its not. i had them tested and they all came back good. they shut each one off individually and back on again. im lost here need some advice. any help would be appreaciated. it has 108000 miles on it if that helps.

anything????

Did they check balance rates or do a return test? Codes?

head gasket?

Smoke at idle is a sign of failing injectors - the injector leaks while "off" and puts fuel into the cylinder(s), causing white smoke (unburnt fuel).

Mine did this at ~75,000 miles, and now again at ~120,000

I hope the dealership will not balk at another replacement under warranty.

i have a 04 lb7 and recently it started to smoke at idle and run rough when you have it in gear. put it in park or neutral and it runs just fine. but in drive or reverse it starts to idle rough. i have poured just about everythihng you can pour through it to make it stop (diesel clean, injector cleaner, 2 stroke oil) nothing works. before you say its my injectors its not. i had them tested and they all came back good. they shut each one off individually and back on again. im lost here need some advice. any help would be appreaciated. it has 108000 miles on it if that helps.

Injectors. Shutting just one at a time off won't always kill the smoke.

Ok, well the smoke is a blue color or more black. And as far as the head gasket i dont know how i would have down that. ok the injectors are all running in the same range though. if they were failing wouldnt they be different? just wandering. i appreciate all the help. so would mind still be under warrenty?

so after a talk with gm mine is udner warrenty. so i took it in and they hooked there scanner to it and said that all my injecotrs are fine they also did a pusle width test or something and checked them with different pressure. so why is it still smoking i asked them and they told me that it was burning oil. well thats not so becuz i check my oil regularly and the smoke that is coming out smells like raw diesel. so now im lost as of what to do. im almost postive its the injectors but i cant get them to change them becuz they claim they are still good. so why all the smoke and missing? confused and pissed at gm for just hooking there scanner to it. i did that at home already. any help?

take it to another dealer, check cp3 and fuel pressure regulator

so after a talk with gm mine is udner warrenty. so i took it in and they hooked there scanner to it and said that all my injecotrs are fine they also did a pusle width test or something and checked them with different pressure. so why is it still smoking i asked them and they told me that it was burning oil. well thats not so becuz i check my oil regularly and the smoke that is coming out smells like raw diesel. so now im lost as of what to do. im almost postive its the injectors but i cant get them to change them becuz they claim they are still good. so why all the smoke and missing? confused and pissed at gm for just hooking there scanner to it. i did that at home already. any help?

Interesting, same deal here. I wasn't going in for warranty due to mine being an 01, but master diesel tech did cp3 pressure command to 160, and it hit 160 and held. He didn't do a balance test because the system is not bleeding off anywhere, indicating a leak/failure, and GM corporate repair service techs advised customer to not do anything at this point in time as it would be a waste of $ (I was intrigued by this).

I did have my t-stats and fluid changed because it wasn't coming up to temp properly, and the test sheet showed it. It was due for a change so I said go for it. He said it's possible the computer was substiting fuel to compensate for heat, but it did not do anything for the smoke, only my normal maintenance schedule:D

No fuel in oil, alittle lope at idle, and smoke while in D or P, and great gas mileage. I'm gonna keep on driving her and keep checking the oil reguarly.

Id say take it to another dealer. Fox where are you located?

I have an 04 lb7 doing the same thing, could it be a oil seal in the turbo?

Interesting, same deal here. I wasn't going in for warranty due to mine being an 01, but master diesel tech did cp3 pressure command to 160, and it hit 160 and held. He didn't do a balance test because the system is not bleeding off anywhere, indicating a leak/failure, and GM corporate repair service techs advised customer to not do anything at this point in time as it would be a waste of $ (I was intrigued by this).

I did have my t-stats and fluid changed because it wasn't coming up to temp properly, and the test sheet showed it. It was due for a change so I said go for it. He said it's possible the computer was substiting fuel to compensate for heat, but it did not do anything for the smoke, only my normal maintenance schedule:D

No fuel in oil, alittle lope at idle, and smoke while in D or P, and great gas mileage. I'm gonna keep on driving her and keep checking the oil reguarly.

It's amazing how most dealer techs have no clue on what they are doing. :rolleyes:

yeah those guys are a bunch of idiots! Im from south western oklahoma little town called hydro. im lost just like you said. i will keep an eye on it and see what happens. took it to another place this afternoon and he said something about my thermostat not keeping operating temp, would this cause it to smoke? so im gona buy a thermostate and see. just trying to get rid of the smoke and little lope at idle. its almost embarrassing at a stop sign.

yeah those guys are a bunch of idiots! Im from south western oklahoma little town called hydro. im lost just like you said. i will keep an eye on it and see what happens. took it to another place this afternoon and he said something about my thermostat not keeping operating temp, would this cause it to smoke? so im gona buy a thermostate and see. just trying to get rid of the smoke and little lope at idle. its almost embarrassing at a stop sign.

I'll save you the aggravation. Injectors are causing the smoke.

Just because the fuel system could build 160mPa of fuel pressure and maintain it does not mean that the injectors are completely OK. The fuel pressure portion that was tested only means the injectors aren't returning an excessive amount of fuel. That's not to say that they aren't dripping fuel or plugged up (biggest causes of white smoke problems).

I'll save you the aggravation. Injectors are causing the smoke.

Just because the fuel system could build 160mPa of fuel pressure and maintain it does not mean that the injectors are completely OK. The fuel pressure portion that was tested only means the injectors aren't returning an excessive amount of fuel. That's not to say that they aren't dripping fuel or plugged up (biggest causes of white smoke problems).

I agree with you. the only thing is the more i look at it, the smokes not white but a blueish grey. almost a tint of black. so i need thermostates regardless, hoping wishing maybe this will clear it up. if truck never gets warm it thinks its cold and keeps dumping fuel into it to warm it up. just a theory, hoping its rite. and since its been doing it for awhile it could be built up deposits inside. just trying to put ideas out there. thanks for all your help guys.

so put the thermos in and it did raise my temp in my truck. also i finally have the answer, hooked it to a scanner for the 5th time and came across my fuel pressure regulator. its at 45 where as it should be at 60 to 65. anyways i increased it to 65 and the truck smooths rite out now rough idle and absolutely no smoke what so ever. the cause of the problem..... running my ppe and the spring giving in. hope that helps somebody out besides me and saves them the hassle. thanks for all the help and advice guys. any thoughts?? or comments??

so put the thermos in and it did raise my temp in my truck. also i finally have the answer, hooked it to a scanner for the 5th time and came across my fuel pressure regulator. its at 45 where as it should be at 60 to 65. anyways i increased it to 65 and the truck smooths rite out now rough idle and absolutely no smoke what so ever. the cause of the problem..... running my ppe and the spring giving in. hope that helps somebody out besides me and saves them the hassle. thanks for all the help and advice guys. any thoughts?? or comments??

Interesting...I have been wondering if it's my bad FPR that is causing the smoke. I even started a thread here on the board about it. If you do change your FPR, please let me know the results.

I find it very odd that our 2 situations are exactly the same. I think it's interesting that we had 2 different techs say the same thing about our temps being the issue. Please keep this post updated and I will do the same. I hit this last fill up extra hard with 2 stroke, which I have seen a good result with the idle, no smoke tho.

How did you verify the spring is bad? I take it that you mean a spring in the FPR? I have never seen one apart.

Interesting...I have been wondering if it's my bad FPR that is causing the smoke. I even started a thread here on the board about it. If you do change your FPR, please let me know the results.

I find it very odd that our 2 situations are exactly the same. I think it's interesting that we had 2 different techs say the same thing about our temps being the issue. Please keep this post updated and I will do the same. I hit this last fill up extra hard with 2 stroke, which I have seen a good result with the idle, no smoke tho.

How did you verify the spring is bad? I take it that you mean a spring in the FPR? I have never seen one apart.
i do too. as if this is the problem for sure ill let you know when i change the FPR. i really hope so. the spring would have to be bad in order for it to let by so i just assumed:) that it would be if this was the case. i dont know for sure,and yes there is a spring on the inside. now begins the long process of putting a new FPR in:(. there a pain. will keep you updated. would like to hear more from you

another quick note! when i idled the truck up to about 2 grand and just kept it there the smoke cleared up and it ran really clean, but as soon as i let off it got back to smoking. almost has to be the FPR. i think. im gona run it by one of my friends today, hes a tech at a local shop here in town and see what he says. maybe that helps you 5Cent.

another quick note! when i idled the truck up to about 2 grand and just kept it there the smoke cleared up and it ran really clean, but as soon as i let off it got back to smoking. almost has to be the FPR. i think. im gona run it by one of my friends today, hes a tech at a local shop here in town and see what he says. maybe that helps you 5Cent.

Good info, but you're just not seeing the smoke because you're actually "burning" some of the extra off, hence the less smoke. There is a good thread about why the smoke is white instead of black here in the last week or so.

I hope you find the FPR fixes your issue, but most likely case is an injector(s) are leaking ever so slightly causing the raw fuel/smoke during lower rpm. I'm just running mine with my normal PS additive and 2 stroke. I keep an eye on the oil, and just try not to look in the mirror often:D

my 04.5 does the same thing i ran injector cleaner through it and it cleaned it all up all problem go away for about a month then it comes back??? idk what to think other than fpr

my 04.5 does the same thing i ran injector cleaner through it and it cleaned it all up all problem go away for about a month then it comes back??? idk what to think other than fpr

Do either of you have any balance rates on your injectors?

i have a 04 lb7 and recently it started to smoke at idle and run rough when you have it in gear. put it in park or neutral and it runs just fine. but in drive or reverse it starts to idle rough. i have poured just about everythihng you can pour through it to make it stop (diesel clean, injector cleaner, 2 stroke oil) nothing works. before you say its my injectors its not. i had them tested and they all came back good. they shut each one off individually and back on again. im lost here need some advice. any help would be appreaciated. it has 108000 miles on it if that helps.

Here's my advice... call around to other dealerships in your area and tell them your problem, see if they have a tech that is skilled in Diesel mechanics... Anybody can plug in a machine to your truck and check rates... You need someone who is going to go above and beyond... I recently had my truck at the dealership for a week, having all 8 injectors replaced due to the SAME exact reason you describe in your original message (smoke and rough idle). My advice... Don't trust a single dealership. I took mine to my local dealer, 6 months ago, they said 2 injectors were "sticking" but all the specs were fine... they recommended I flush my injectors, told me I'd have to in the event any coverage would be awarded to me. I figured, if it had to be done in order for my truck to be covered, go ahead. Bad mistake on my part... picked up my truck later that afternoon, truck still smoked. I felt like they never even looked at it. $300 later, I left unsatisfied. Last week, I decided to take it to another dealership, see what they could find. If all else failed, I'd have to pay the dealer another $90 for looking at it. It was well worth it as they tech found that my injectors were over fueling, causing my motor to completely fill up with diesel and flood into the oil. All-in-all, I picked up my truck 2 days ago, paid them $82 for an oil change... and the truck runs like a champ. Not a breathe of smoke and idle... well, it's hard to tell the truck is even running. LOL. Good luck whatever you decide to do. Whatever you do, get multiple opinions as it could save you $3500.

I just as you dumped everything I could find into the tank... Diesel Kleen, 3 qts ATF... smoke never cleared up. You're going to keep throwing away money on these products trying to fix the problem. Get it fixed, then, continue the additives on fill ups

I am having the same issues with my 02. White smoke at idle and then , well when driving it nothing (that I can see anyway).
Truck runs fine, no coolent loss at all and no rough idle.... I haven't even noticed a loss of milage, but for the most part I never check it anyway.
I've talked to a couple of differnt shops now and they each say something different. One says I need new injectors ($3600) and the other says I have a bad head gasket ($????) I have no idea which one it is but know it needs to be fixed soon.

Any thoughts?

In my search for a FPR i cant find a aftermarket one only a OEM one. Any ideas for a aftermarket one??? i will call around this afternoon and see what they tell me and waht they say. Thanks for the info guys. will keep posted. OH!!! yes my balances rates where good... but i notcied when i hooked my own scanner to it that a few where 12mms less than the rest EX. all where at 40 give or take 1. then 2 where at 29, any ideas?

Here's one from Merchant Automotive..$194

http://www.merchant-automotive.com/oemlb7fuelsystem.aspx

Here's one from Merchant Automotive..$194

http://www.merchant-automotive.com/oemlb7fuelsystem.aspx

Thanks for the info. im gona order one and have my brother pu tit in for me. hes a diesel mechanic in the witchita area.

yeah i found the oem FPR's but still no luck in a aftermarket one??? or even if they make them:confused:

yeah i found the oem FPR's but still no luck in a aftermarket one??? or even if they make them:confused:

I have never seen one. Please update when you get it installed!

Mine started to smoke last Thursday, no rough idle, nothing seemed wrong (except white smoke). Wasn't able to get an appointment until after the weekend. Put in some Diesel Kleen (more than I was supposed to). Ran it awhile and let it sit over night. fired it up on Saturday and no more smoke. Ran it all weekend and still not smoke on Monday morning. Could it have been a stuck injector, or did I just hide the problem by using the DK? Also, does it hurt to put more than the recommended amount as described on the bottle?

My LLY is also having this issue... all my balance rates are +/- 2.0 except #7... it is +8.0-12.0 Could i have just 1 bad injector? and is there any injector warranty on the LLY injectors??

My LLY is also having this issue... all my balance rates are +/- 2.0 except #7... it is +8.0-12.0 Could i have just 1 bad injector? and is there any injector warranty on the LLY injectors??

Sure can have just one...do a search for LLY service bulletin. All depends on in service date.

Well I've been smoking for the last 5K miles. I just changed the oil today, and will keep driving her. 2stroke is easing the pain of the FPR, but I am not going to change it out until I hear back from a few more people that are changing theirs out. Eventually it will need injectors, but I am going to keep driving it until it starts making oil...

Well I've been smoking for the last 5K miles. I just changed the oil today, and will keep driving her. 2stroke is easing the pain of the FPR, but I am not going to change it out until I hear back from a few more people that are changing theirs out. Eventually it will need injectors, but I am going to keep driving it until it starts making oil...
i odered that FPR and it came in here at a local shop. to my surprised they only charged me 95.24 without tax:confused: i thought they were in the 200 area. now all that is left to do is put it in. i will let ya know. 5cent i hope this is our problem, ive been doing the same with the 2 stroke and everynow and then some bg diesel clean.

i odered that FPR and it came in here at a local shop. to my surprised they only charged me 95.24 without tax:confused: i thought they were in the 200 area. now all that is left to do is put it in. i will let ya know. 5cent i hope this is our problem, ive been doing the same with the 2 stroke and everynow and then some bg diesel clean.

Awsome, look foward to hearing from you when it's installed. I hope your truck purrs like new:D

lb7 in the 4500 is on its 6th set of injectors 171k miles. soon to be down the road in favor of a pete 337

Not that I have much to add, but I had the same problem something like 8 months ago and thought the same thing on the injectors. The only thing that made me skeptical was the fact that the problem was ONLY at idle IN GEAR. Once shifted to neutral or park, the smoke & chug was gone. It came and went a few different times, all the while noticeing it was either raining or had just rained (didn't know if that mattered). Needless to say, it hasn't happened again since (about 10k miles). I do run 16oz of 2-stroke/32gal fill-up of fuel (but not often I fill 'er up), and from time to time an injector cleaner. Runnin great without smoke at this time and it's still all stock runnin on AmsOil with third-party testing saying all is good too.

I Wish You Luck Buddy, But I Just Went Through The Same Thing. I Had All The Same Issues You Are Having. Turns Out It Was The Injectors And Cups............good Luck On The 7 Year 200,000 Mile Thing Thanks For Nothing Chevy, I Just Had It Done Last Week $5000 Big Ones, My Truck Has 84,000 Miles On It And I Was 5 Months Outside Of The 7 Yr Mark. I Called Gm Corp In Detroit And Long Story Short They Said Sorry About Your Luck Even After Explaining How I Have Owned Nothing But Chevy's My Whole Life And After Supporting Them For Over 10 Yrs This Is How They Treat A Loyal Customer I Wasn't Even Asking For A Full Reimbursement. I'll Tell You What This Might Be The Last Chevy I Own, It Was Like A Punch In The Face.........check With Another Dealer Cause After I Had It Done I Found Out If I Brought It To A Different Dealer They Would Have Covered It.....good Luck.thanks For Nothing Chevy!!

I Wish You Luck Buddy, But I Just Went Through The Same Thing. I Had All The Same Issues You Are Having. Turns Out It Was The Injectors And Cups............good Luck On The 7 Year 200,000 Mile Thing Thanks For Nothing Chevy, I Just Had It Done Last Week $5000 Big Ones, My Truck Has 84,000 Miles On It And I Was 5 Months Outside Of The 7 Yr Mark. I Called Gm Corp In Detroit And Long Story Short They Said Sorry About Your Luck Even After Explaining How I Have Owned Nothing But Chevy's My Whole Life And After Supporting Them For Over 10 Yrs This Is How They Treat A Loyal Customer I Wasn't Even Asking For A Full Reimbursement. I'll Tell You What This Might Be The Last Chevy I Own, It Was Like A Punch In The Face.........check With Another Dealer Cause After I Had It Done I Found Out If I Brought It To A Different Dealer They Would Have Covered It.....good Luck.thanks For Nothing Chevy!!

Easy hoss, I agree it's a raw deal, but I love my duramax. I don't have to worry about tranny or rear end issues, and outside of injectors the engine is well designed. If I get another 70K out of this set I'll take it.

Chevy should have issued a recall, but the service bulletin was helpful. I am actually surprised that so many dealers are getting post date trucks fixed.

Don't get me wrong I love my duramax. I just think it should have been a full blown recall.everyone has spent their hard earned money on a $40000 + truck Chevy should Have just put a mileage stipulation not a timeframe. And for corporate to say sorry for your luck. Unsatisfactory

So 5cent i put the FPR in last night and no change :(. so as off now i guess you guys were right. it has to be my injectors. i will try to find another dealer to warranty my ,my baby. sorry for the long wait on the update, with it being thanksgiving and all i didnt have alot of time. another quick note should i take off my aftermarket AEM intake before i take it in again:confused: last place i took it too i took the intake off. just wandering. thanks guys.

So 5cent i put the FPR in last night and no change :(. so as off now i guess you guys were right. it has to be my injectors. i will try to find another dealer to warranty my ,my baby. sorry for the long wait on the update, with it being thanksgiving and all i didnt have alot of time. another quick note should i take off my aftermarket AEM intake before i take it in again:confused: last place i took it too i took the intake off. just wandering. thanks guys.

Bummer to hear brother. No worries on the wait, as I'm still driving mine and she keeps on smoking:D

I did find a shop 2hrs away (Findlay, OH) that is very familiar with this issue, replaces them all the time, and offer a 1yr unlimited mileage on parts and labor and only for $3K:eek:

Yes, I would take anything non OEM off before trying to get covered on 7/200K bulletin.

Bummer to hear brother. No worries on the wait, as I'm still driving mine and she keeps on smoking:D

I did find a shop 2hrs away (Findlay, OH) that is very familiar with this issue, replaces them all the time, and offer a 1yr unlimited mileage on parts and labor and only for $3K:eek:

you must be talking about International fuel systems. they are very very knowledgeable about all things diesel. i would trust them if i had to pay someone to put injectors in.

you must be talking about International fuel systems. they are very very knowledgeable about all things diesel. i would trust them if i had to pay someone to put injectors in.

Busdriver, thank you for posting! I remembered someone was from the area, and yes, International is who I am talking about. The guy answered every question I had and was very nice. I know of a truck that went in today (scheduled appt. 1-2 wks ago), and I'm looking foward to hearing his about his experience.