Duramax LB7 questions

Foose04 · 04-20-2011, 10:42 AM

Hey guys, been looking at picking up a new daily driver and something that can pull a boat or car trailer later on.

I got my eye on a 02 chevy, with the LB7. Research on my end shows these have injector problems and it's not a quick swap kind of job. The truck has 86,000 miles on it and is 100% stock.

Any feedback on these trucks and also what to look for on inspecting the truck over for other known problems?

minytrker · 04-20-2011, 11:12 AM

I have a 03 LB7 dually...been the best truck I ever had. I hasd injectors put in at 90k and now I have one starting to go out at 220k. Supposedly the new injectors that came out a year or so are suppose to last.

1998ta__1991rs · 04-20-2011, 12:38 PM

i think the 02's had a decent injector warrenty, and no its not a quick simple job, the injectors alone are a couple grand for the set. LB7's seem to be about the best motors for fuel economy though, they had a lot less emissions crap than the lly's and lbz's

Jimmyz18 · 04-20-2011, 04:55 PM

I have an 02, the warranty was extended to 7 years and 200,000, which is past the tiime now. I had my injectors replaced under warranty, but no other issues with the truck. I have 208,000 on it now and hopeing to reach 500,000

Jim

Darryl Buckner · 04-20-2011, 04:58 PM

Buy a Cummin's!

Diablo · 04-20-2011, 08:33 PM

Well I worked for GM for a quite a while now and I found the the injectors are the main concern. We do warranty the injectors but if we find rust on them then it would have to come out of pocket. The injectors are not cheap and the labor is even worse. If you do recommended diesel treatment and fuel filter replacement when your sapposed to then you won't have an issue. Other then that its a srong truck to get. Let me know if you need to bring it by the shop so I can take a closer look at it

minytrker · 04-21-2011, 12:27 AM

Quote:

Originally Posted by Diablo

If you do recommended diesel treatment and fuel filter replacement when your sapposed to then you won't have an issue.

That is very far from the truth. Its a shitty design in injector and injector cup and most of the time there isnt anything you can do. Getting water in your fuel can make them show rust and definitely doesnt help them, but its just GM's way to get out of the warranty. Just like when I had my first injector go I had them change all of them and then GM later changed it for them to only change the one that is bad. I change my fuel filter every 5,000 miles and use diesel treatment and still had another injector go bad. You dont know if its the injector or cup until you tear it down.

I still prefer the LB7 over any other model. Its has no emissions, and with a custom tune I get 19-22mpg on the highway with big heavy 19.5's. I also get 10mpg towing weighing 22,000 lbs going 70mph.

1998ta__1991rs · 04-21-2011, 01:46 AM

buy an lmm, 18 mpg pulling 37's and still runs strong at the track

Darryl Buckner · 04-21-2011, 09:03 AM

Cummin's baby! Get 22mpg empty, 18mpg towing car on 18 foot open trailer, and 14 to 15mpg pulling 50 foot Pace Bigfoot trailer with living quarters. Oh and other then a 40.00 water pump, that took about 30 minutes and 2 10mm screws to change, and you don't even have to drain the entire cooling system to do it, I have had zero problems. Still on origional batteries, brakes, ect. I upgraded the clutch cause the stocker could only take 800 plus foot pounds for about 80000 miles though, but thats my fault. You can almost stand on either side of the motor to work on it if necessary.

minytrker · 04-21-2011, 10:36 AM

Quote:

Originally Posted by Darryl Buckner

Cummin's baby! Get 22mpg empty, 18mpg towing car on 18 foot open trailer, and 14 to 15mpg pulling 50 foot Pace Bigfoot trailer with living quarters. Oh and other then a 40.00 water pump, that took about 30 minutes and 2 10mm screws to change, and you don't even have to drain the entire cooling system to do it, I have had zero problems. Still on origional batteries, brakes, ect. I upgraded the clutch cause the stocker could only take 800 plus foot pounds for about 80000 miles though, but thats my fault. You can almost stand on either side of the motor to work on it if necessary.

It won't get mileage stock. You probably have air bags to so your truck doesn't sit on the bump stops, lol. I tow on my stock tune since cruise control is smoother when towing big trailers, plus easier on my trans when it down shifts. Your model dodge is probably the best one out though if I had to pick a dodge. The new ones come in last on every test compared to ford and chevy. A friend has 2011 dodge and it is junk, it gets horrible mileage and squats really bad with normal size loads.

1998ta__1991rs · 04-21-2011, 10:40 AM

the cummins is a great motor, too bad they put it in such shitty of a truck

BigHemi · 04-21-2011, 01:52 PM

I have a 2004 GMC Duramax LB7 w/ 200k miles and it still has the original injectors. However, I am about to rip the heads off of it to replace head gaskets b/c it's blowing water out of it.

Go drive the snot out of that LB7, then pop the hood and see if the upper radiator hose is hard as a brick. If it is, walk away from it.

MonteC · 04-21-2011, 02:15 PM

7.3l

Darryl Buckner · 04-21-2011, 02:42 PM

Quote:

Originally Posted by minytrker

It won't get mileage stock. You probably have air bags to so your truck doesn't sit on the bump stops, lol. I tow on my stock tune since cruise control is smoother when towing big trailers, plus easier on my trans when it down shifts. Your model dodge is probably the best one out though if I had to pick a dodge. The new ones come in last on every test compared to ford and chevy. A friend has 2011 dodge and it is junk, it gets horrible mileage and squats really bad with normal size loads.

I honestly gained about 2 miles per gallon with the tune, so mileage still wasn't bad stock. And you are right about the airbags, cause mine sat on the bumpstops without the bags, with the 50' trailer, but its 17000 pounds so I can't conplain. You know how it is 1 ton truck with 2 tons sitting in the bed over the axle. I don't have down shift problems cause of the 6 speed. I have looked at the new Dodge trucks with the 6.9 and all the junk under the hood of those is just as bad as any other truck, mine is just so easy to get to everything under the hood. Zack is correct also, the inside of mine isn't as nice as the Chevy or Fords, but the new ones like Wes and Mike has is really nice. I wouldn't mind having that Allison transmission though, actually I could hook it up to mine..

gearmesh, inc. · 04-21-2011, 07:07 PM

I'll give Cummins the nod.

Attachment 608

Attachment 609

cmd · 04-21-2011, 09:51 PM

Quote:

Buy a Cummin's!

Troof!!!!!

04-20-2011, 10:42 AM	#1
Foose04 Senior Member Join Date: Feb 2010 Posts: 965	Duramax LB7 questions Hey guys, been looking at picking up a new daily driver and something that can pull a boat or car trailer later on. I got my eye on a 02 chevy, with the LB7. Research on my end shows these have injector problems and it's not a quick swap kind of job. The truck has 86,000 miles on it and is 100% stock. Any feedback on these trucks and also what to look for on inspecting the truck over for other known problems? __________________ 12 GMC Denali HD: 4x4, 12" Bullet Proof, 24x12 American Forces, 40x15.50 Toyo M/T's, h&s mini max, deleted, 5" axle dump, S&B intake,tractions bars, air bags. 04 GMC 1500RST: TMS Iron 347/S480/4l80E - 9.63@143.22 05 GMC 2500HD: LLY@372HP/669TQ, 4x4, 8" FabTech, 4.56 gears & 37" Toyo M/T's

04-20-2011, 11:12 AM	#2
minytrker Senior Member Join Date: May 2008 Posts: 1,089	I have a 03 LB7 dually...been the best truck I ever had. I hasd injectors put in at 90k and now I have one starting to go out at 220k. Supposedly the new injectors that came out a year or so are suppose to last. __________________ 1999 Z28 Camaro\|Cut up 2003 CC Duramax Dually\|19.5 w/245/70/19.5\|5in exhaust 2009 G8 GT 408hp/402tq sae\|Rotofab CAI\|LS9 Cam\|Headers\|GXP Mufflers\|Custom System 2009 Tahoe stock

04-20-2011, 12:38 PM	#3
1998ta__1991rs Senior Member Join Date: Jun 2008 Location: West Ash Posts: 4,283	i think the 02's had a decent injector warrenty, and no its not a quick simple job, the injectors alone are a couple grand for the set. LB7's seem to be about the best motors for fuel economy though, they had a lot less emissions crap than the lly's and lbz's __________________ Funny

04-20-2011, 04:58 PM	#5
Darryl Buckner The Top Dog Join Date: Dec 2007 Posts: 2,318	Buy a Cummin's! __________________ When the people fear the government, there is tyranny. When the government fears the people, there is liberty. Thomas Jefferson

04-21-2011, 01:46 AM	#8
1998ta__1991rs Senior Member Join Date: Jun 2008 Location: West Ash Posts: 4,283	buy an lmm, 18 mpg pulling 37's and still runs strong at the track __________________ Funny

04-20-2011, 04:55 PM	#4
Jimmyz18 Senior Member Join Date: Aug 2010 Location: Ladson Posts: 734	I have an 02, the warranty was extended to 7 years and 200,000, which is past the tiime now. I had my injectors replaced under warranty, but no other issues with the truck. I have 208,000 on it now and hopeing to reach 500,000 Jim

04-20-2011, 08:33 PM	#6
Diablo Senior Member Join Date: Oct 2009 Posts: 132	Well I worked for GM for a quite a while now and I found the the injectors are the main concern. We do warranty the injectors but if we find rust on them then it would have to come out of pocket. The injectors are not cheap and the labor is even worse. If you do recommended diesel treatment and fuel filter replacement when your sapposed to then you won't have an issue. Other then that its a srong truck to get. Let me know if you need to bring it by the shop so I can take a closer look at it

04-21-2011, 09:03 AM	#9
Darryl Buckner The Top Dog Join Date: Dec 2007 Posts: 2,318	Cummin's baby! Get 22mpg empty, 18mpg towing car on 18 foot open trailer, and 14 to 15mpg pulling 50 foot Pace Bigfoot trailer with living quarters. Oh and other then a 40.00 water pump, that took about 30 minutes and 2 10mm screws to change, and you don't even have to drain the entire cooling system to do it, I have had zero problems. Still on origional batteries, brakes, ect. I upgraded the clutch cause the stocker could only take 800 plus foot pounds for about 80000 miles though, but thats my fault. You can almost stand on either side of the motor to work on it if necessary. __________________ When the people fear the government, there is tyranny. When the government fears the people, there is liberty. Thomas Jefferson

04-21-2011, 10:40 AM	#11
1998ta__1991rs Senior Member Join Date: Jun 2008 Location: West Ash Posts: 4,283	the cummins is a great motor, too bad they put it in such shitty of a truck __________________ Funny

04-21-2011, 01:52 PM	#12
BigHemi Senior Member Join Date: Feb 2010 Location: Marion, SC Posts: 233	I have a 2004 GMC Duramax LB7 w/ 200k miles and it still has the original injectors. However, I am about to rip the heads off of it to replace head gaskets b/c it's blowing water out of it. Go drive the snot out of that LB7, then pop the hood and see if the upper radiator hose is hard as a brick. If it is, walk away from it.

04-21-2011, 02:15 PM	#13
MonteC Senior Member Join Date: Oct 2009 Location: Summerville Posts: 4,431	7.3l __________________ Griffin Transmission -Home of the most badassest Monte Carlo- Cell: 843-276-0554 Shop: 843-793-4607 04 RSX 06 Ridgeline 86 Monte Carlo

04-21-2011, 07:07 PM	#15
gearmesh, inc. creepy azz cracka Join Date: Nov 2008 Location: Summerville Posts: 1,587	I'll give Cummins the nod. Attachment 608 Attachment 609 __________________ "I came into this world kicking, screaming,and covered in someone else's blood, I have no problem leaving the same way!" ÔÇ£If you carry a gun, people will call you paranoid. ThatÔÇÖs ridiculous. If I have a gun, what in the hell do I have to be paranoid about?ÔÇØ -Clint Smith, Thunder Ranch. Last edited by gearmesh, inc.; 11-15-2013 at 07:36 PM.