View Full Version : Help with smoking 01 Dmax
My truck is smoking fairly heavily at idle. I had a rough idle last year and in August started geting a P0089 code on and off. Then it went away sometime in the fall and haven't had a code since then but the smoking has gotten worse. I still have good power when pulling a 13,000 lb 5th wheel. i have fuel rail pressure at idle in the 5000lb range that will suddenly spike to 7500 lbs then slowly drop back to the 5000 lb range. We have replaced the fuel rail pressure sensor and checked all electrical connections and it still smokes and runs a little rough at idle. The truck has 149,000 miles on. The injectors were replaced by GM at 78,000 miles. I'm looking for some suggestions where to go next. My son in law is a diesel mechanic but is not familiar with the Dmax and he is working on it with me so we will do our own work.
tkgmfan
I had the same symptoms several times in my '01. It's almost for sure the injectors. I put 280,000 miles on my '01 Duramax and was literally one of the first people to experience the LB7 injector problem. I am NOT a mechanic and there may be something else wrong as well but, injectors on my truck lasted from about 70,000 miles to about 100,000 miles at the outside. I sold the truck to a friend and he experienced the same symptoms at about 325,00 miles and changed injectors.
I had an awful time early on with GM about this issue, and spent around $13,000 on parts,(primarily on 18 injectors @ $375 - $550 ea.) and labor before the 200,000 mile Extended warranty came out. (GM paid me back a little over $11,000 in 2004).
The symptoms were always smoking at idle! Otherwise the truck ran perfectly.
You may still be under warranty so I would suggest a dealer ASAP. Good luck
Tony
Tony, Thanks for the info. Today we found one bad injector and replaced it. Got it back together and it runs great but at this point it is still smoking both at idle and under acceleration. We only put about a mile on it. My son in law is going to pull the glow plugs again in the am and see if anything is different. I got my member info straightened out today and was able to read the excellent article on changing the injectors. Thanks to the author. If anyone has any additional ideas, I'd love hear them before this thing breaks me. I love the truck and hope to also get 300,000 miles from it. It's a shame that the after market hasn't come up with a better injector that will hold up longer.
Tom
tkgmfan,
Something I forgot you mention in my first reply was thedieselpageforums.com was of invaluable help when I was going through the trials and tribulation in 2002 - 2004 with my '01. Kudos to all of the people who contribute to this forum. The education, information and just plain support was a great help to me. Thanks, Thanks and more Thanks.
I haven't read the article on changing injectors because I no longer have the '01, so what I am going to say may be covered in it. One of my early problems was the dealer did not install the injectors and seals properly. This caused leakage around the seal. The leaking diesel goes directly into the crankcase, so I ended up first with low oil pressure and a little smoke then fluid leaking out everywhere it could. This could have caused hydraulic lock as well. The dealer never figured did figure it out. I had to tell them what the problem was based on the information I got on The diesel page forums. You might want to check your oil.
FYI, I have an '05 with the LLY motor and the new head design and I am just now changing my first injectors. #2 is malfunctioning completely and #4 is out of tolerance. All of the others are within toloerance. I have 232,000 miles on it. Like you, I love the truck.
Are you sure #2 is an injector problem and not a connector problem??? There is an updated connector for #2 & 7 injectors. I've seen one or the other get the connection problem and cause others to look bad based on balance rates. Fix two first then check #4 out again.
Madmatt,
Thanks for the advice. I did the connector update a while back, but we will double check it. I should know today. Thanks
I just returned from a 120 mile trip with my 5th wheel and the truck ran great and no smoking:). Hope that fixes it for a while. Thanks for the help. I know that these forums can be of great assitance. It's a real shame that so many GM dealer mechanics can't fix these engines when it's more than just reading a code. Too bad they don't have common sense troubleshooting skills.
Tom
What fixed it??? BTW, I'm a dealer tech, so just stop by when your in the Louisville KY area and I'll fix ya up if need be.
Matt, I've been offline for a while. The last repair that we did was to replace #1 injector (left front) and #1 & 3 glow plugs. Last weekend I ran a long solo trip in the ozark hills, mostly highway driving and got 17.4 mpg ;) manual calculated. It seems to be running great again. Hopefully the other 7 injectors will continue to perform for a long time.
Mark Rinker
05-11-2009, 06:20
Not sure how glowplug replacement would cure smoking after the one bad injector was replaced? Please explain...
If you went to the trouble to tear down one side of the engine - why not replace all four, and wait for an injector to fail on the other side (bank) ?
GM took the single injector approach, then one bank approach, then mandated that all 8 injectors be replaced under warranty for the LB7s.
With your miles, its just a matter of time until you have that side of the engine back apart...when you do, my advice would be to do the other three!
mattb5150
06-25-2009, 12:49
Okay, truck just back from dealer, #7 injector is causing big smoke when I get on it and detonation at startup, otherwise runs great. Of course it doesn't exceed GM specs for full replacement policy. The truck has 110k miles and had injectors done at 35k according to warranty history, I purchased at 80k miles. Service writer suggests that I have the #7 injector replaced for $1,400. I'd like to keep the truck for a while and have secondary filtration installed now (CAT) which I hope will prevent further problems. Wondering what you guys think?
Matt
Mark Rinker
06-25-2009, 13:10
What year and engine model? If its the '03 (LB7) that you have listed, it should still be covered under 7yr, 200K mile injector warranty, depending on your in-service date. That warranty calls for ALL eight injectors to be replaced...
DmaxMaverick
06-25-2009, 13:36
Okay, truck just back from dealer, #7 injector is causing big smoke when I get on it and detonation at startup, otherwise runs great. Of course it doesn't exceed GM specs for full replacement policy. The truck has 110k miles and had injectors done at 35k according to warranty history, I purchased at 80k miles. Service writer suggests that I have the #7 injector replaced for $1,400. I'd like to keep the truck for a while and have secondary filtration installed now (CAT) which I hope will prevent further problems. Wondering what you guys think?
Matt
Either get that dealer to play ball, or find another dealer. Your complaint should certainly be covered by the extended warranty campaign. Any tech who relies on only the balance rates for diagnosis is no tech. If they somehow managed to diagnose a major injector leak on any injector, in "specs" or not, they should be taking care of this. Injector leaks were the original reason for the extended warranty in the first place. Balance rates are only one of several possible diagnostic symptoms.
Mark Rinker
06-25-2009, 14:00
Either get that dealer to play ball, or find another dealer. Your complaint should certainly be covered by the extended warranty campaign. Any tech who relies on only the balance rates for diagnosis is no tech. If they somehow managed to diagnose a major injector leak on any injector, in "specs" or not, they should be taking care of this. Injector leaks were the original reason for the extended warranty in the first place. Balance rates are only one of several possible diagnostic symptoms.
...and the 'detonation' you report at startup is indicative of a leaking injector, one that could potentially go 'blowtorch' on you, melting a hole through a piston top.
Don't wait to get this solved. If you get any fuel knock under acceleration, don't continue to operate the truck.
DmaxMaverick
06-25-2009, 14:17
...and the 'detonation' you report at startup is indicative of a leaking injector, one that could potentially go 'blowtorch' on you, melting a hole through a piston top.
Don't wait to get this solved. If you get any fuel knock under acceleration, don't continue to operate the truck.
Yes. Detonation is a strong indicator injector(s) are leaking when idle (no power, engine off). Most likely, a cracked body and/or eroded ball/seat. The symptom will seam like a hot gasser with the timing to far advanced. Usually, it only "detonates" (knocks, kicks-back) once on startup. If the leak becomes too large, it can actually hydro-lock the cylinder, and that can cause major internal mechanical damage.
mattb5150
06-25-2009, 15:34
Hey Guys,
Mark-Yes it's the '03 and I am aware of the policy, been there before with my previous '02. Warranty covered until 2/1/10.
Mav-Receipt shows the following "Verified concern, performed diagnostic per doc#796346. #7 Injector fuel rate measuring 6.8mm Max is 4mm injector is bleeding down. Fuel pressure on right bank minimum is 157 measured 160. Does not meet injector replacement requirements."
service writer suggested calling GM Customer Service.
Mark & Mav-I know what you mean about blowtroch after reading about Redbirds motor. That's why I want to take care of this right away and now it seems the most prudent thing to do on my part is go and replace the one out of my pocket rather than wait. No fuel knock noticed after initial startup.
Matt
Duramaster
06-25-2009, 19:02
$1400 for one injector.................. OUCH!!!!! Let's see............ the injector is $240 - 275 each, the lower, reusable rocker cover gasket is $80 or so and then five return seals under the rocker and the a seal at the FICM ($20 at most). So quick math shows $375 in parts and $1025 in LABOR!!! Which means 10 HOURS!!!!!!!!!!!!! Now I know there may be more parts and less labor but GEE WIZ!!! I don't know how you DMAX owners can afford to fix your vehicles. Regardless, $1400 seems just a WEE bit high. By the way, I can do the right bank in less than three hours and We get payed hourly, not flat rate so I take a little more pride in my work.
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