I'm shopping for a used Duramax, 06-07 LBZ. I located an 06 that seems clean and priced right, but per the VIN (8th digit is 2), it is an 06 LLY. I have read that the only difference with an 06 LLY and an 06 LBZ is the milder LLY tuning, that all engine and drive train components are identical to the LBZ, including that it should have the 6 speed Allison. Is this correct? If this is all correct, I am still interested in this truck, and my question becomes, how much should the fact it is an 06 LLY affect the value of the truck (as opposed to an 06 LBZ)?Second question about this truck -- It has 130K on the clock, the owner is a young guy, and he said he replaced the turbo and the head bolts at 125K. I asked why, he said his mechanic scared him telling him if the turbo blows, it will take out the engine, so he went for it, and did the head bolts at the same time. My questions are what concerns should I have about this history and this repair, and what should I look for when I go inspect the truck tomorrow?Two questions about value/resale value: First question: How much does this truck being an 06 LLY reduce the value of this 06 Duramax, compared to an 06 LBZ?Second question about value: The truck has a minor dent in the rear quarter panel. The accident shows up on AutoCheck (like CarFax), and shows a rating for similar vehicles of 81-89. And it gives this truck a 74, I believe obviously because of this minor accident on the record. I am not concerned about the dent, very minor, but my question is, how much does this affect the value of the truck?Thanks for any info!

Are you worried about driving or resale? Wouulnd't get one that doesn't have the z engine. 8th digit should be a z.The LBZ was introduced for 2006, eventually phasing out the LLY. With it came a huge leap in performance, offering 360 hp and 650 lb-ft torque.I would be worried about the body damage, and it coming from a 20 something year old!

Here are the differences. It's more than just a tune..also some heavier duty components....LLY/LBZThe LBZ (engine code "D") debuted in late 2006 and continued into 2007 sold only in the "classic" body style. It has an improved engine computer tune that produces increased power and torque over the 2005.5 LLY version of the motor. First appearance of the Duramax in the Express/Savanna vans.Changes include: Cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased power and torque Upgraded main bearing material increases durability Revised piston design helps lower compression ratio to 16.8:1 from 17.5:1 Piston pin bore diameter increased for increased strength Connecting rod “ I ” section is thicker for increased strength Cylinder heads revised to accommodate lower compression and reduced cylinder firing pressure Maximum injection pressure increased from 23,000 psi (1,585.8 bar) to more than 26,000 psi (1,792.6 bar) Fuel delivered via higher-pressure pump, fuel rails, distribution lines and all-new, seven-hole fuel injectors Fuel injectors spray directly onto glow plugs, providing faster, better-quality starts and more complete cold-start combustion for reduced emissions Improved glow plugs heat up faster through an independent controller Revised variable-geometry turbocharger is aerodynamically more efficient to help deliver smooth and immediate response and lower emissions Air induction system re-tuned to enhance quietness EGR has larger cooler to bring more exhaust into the system First application of new, 32-bit E35 controller, which adjusts and compensates for the fuel flow to bolster efficiency and reduce emissions"

Sounds like the kid had a tuner on it or something.Be hard to tell if he did .My 07 had 110k miles on it when i traded it in and never had a issue blowing anything with efi live tuning.sounds like the kid beat the he'll out of it .Most mechanics will suggest putting headstuds on ford 6.0s.Lly had some overheating issues.Was a easy fixDepends what he wants for itbe iffy on that bottom end

crcr wrote:I'm shopping for a used Duramax, 06-07 LBZ. I located an 06 that seems clean and priced right, but per the VIN (8th digit is 2), it is an 06 LLY. I have read that the only difference with an 06 LLY and an 06 LBZ is the milder LLY tuning, that all engine and drive train components are identical to the LBZ, including that it should have the 6 speed Allison. Is this correct? If this is all correct, I am still interested in this truck, and my question becomes, how much should the fact it is an 06 LLY affect the value of the truck (as opposed to an 06 LBZ)?Second question about this truck -- It has 130K on the clock, the owner is a young guy, and he said he replaced the turbo and the head bolts at 125K. I asked why, he said his mechanic scared him telling him if the turbo blows, it will take out the engine, so he went for it, and did the head bolts at the same time. My questions are what concerns should I have about this history and this repair, and what should I look for when I go inspect the truck tomorrow?Two questions about value/resale value: First question: How much does this truck being an 06 LLY reduce the value of this 06 Duramax, compared to an 06 LBZ?Second question about value: The truck has a minor dent in the rear quarter panel. The accident shows up on AutoCheck (like CarFax), and shows a rating for similar vehicles of 81-89. And it gives this truck a 74, I believe obviously because of this minor accident on the record. I am not concerned about the dent, very minor, but my question is, how much does this affect the value of the truck?Thanks for any info!First question= yes.Second question= Not much if any at all. The ones that know this fact know the cost of a tune will get them an LBZ. The ones that don't know this don't care.Third question (second for you)= depends on how good the tech was and how good of a job he did.Fourth question= I have no idea how much a minor accident affects the value.I do know this. The LBZ sells fast and even for crazy prices. They are very sought after. If you don't buy it soon, someone else will. If you think about this for very long you won't have to think about it at all because it will be gone.Good luck.

Bottom line for me is pass on this truck. Find a true LBZ without all the mystery

Questions for LBZ experts about 06-07 Duramax 2500HD truck

Tystevens
Explorer
Mar 03, 2014
CKNEK wrote:
DUO_CORE wrote:
2006 LLY is the same except for the tune. 2004/5 LLY were the overheaters.
As long as it has the 6spd Allison it's an '06.

Exactly.

What get confusing is GM produced two versions of the LLY early models 04.5 to 05 and late models 06. I would not be scared of a late model LLY.

The 06 LLY and LBZ both have the 6 speed Allison which has the +/- button on the shifter column.

Yep, this is the right 'version' of the facts.

GM didn't do anyone any favors in their branding engines and changing models -- not even their own salesmen can keep it straight. Simply put, there is an '04.5-05 LLY, and then there is the '06 LLY, which is entirely different.

The '06 LLY ran only for the first quarter of the '06 model year, which was available for purchase in the latter part of '05 (to add to the confusion!). The '06 LLY is the same engine as the LBZ, just slightly detuned.
Turtle_n_Peeps
Explorer
Mar 02, 2014
CKNEK wrote:
DUO_CORE wrote:
2006 LLY is the same except for the tune. 2004/5 LLY were the overheaters.
As long as it has the 6spd Allison it's an '06.

Exactly.

What get confusing is GM produced two versions of the LLY early models 04.5 to 05 and late models 06. I would not be scared of a late model LLY.

The 06 LLY and LBZ both have the 6 speed Allison which has the +/- button on the shifter column.

X3 or whatever it is now.

crcr here is some reading for you.

More reading.

More reading

In any event ALL 06 LLY or LBZ's are; if auto's; are 6 speeds.
CKNEK
Explorer
Mar 02, 2014
DUO_CORE wrote:
2006 LLY is the same except for the tune. 2004/5 LLY were the overheaters.
As long as it has the 6spd Allison it's an '06.

Exactly.

What get confusing is GM produced two versions of the LLY early models 04.5 to 05 and late models 06. I would not be scared of a late model LLY.

The 06 LLY and LBZ both have the 6 speed Allison which has the +/- button on the shifter column.
crcr
Explorer
Mar 02, 2014
DUO_CORE wrote:
2006 LLY is the same except for the tune. 2004/5 LLY were the overheaters.
As long as it has the 6spd Allison it's an '06.

Thank you. How can one tell for sure that it has the 6 spd Allison?
DUO_CORE
Explorer
Mar 02, 2014
2006 LLY is the same except for the tune. 2004/5 LLY were the overheaters.
As long as it has the 6spd Allison it's an '06.
crcr
Explorer
Mar 02, 2014
Thanks to all for your answers. Much appreciated.

I have googled this question -- about what the difference is between the 2006 LBZ (8th digit of VIN is D) and 2006 LLY (8th digit of VIN is 2, and 10th digit is 6, indicating the fact that it is a 2006). In the responses from you kind folks, I see there is a mix of opinions on whether the engine in the 2006 LLY is the same as the engine in the 2006 LBZ, except for the milder tune. I have also read that comparisons of engine part to engine part for these two engines have shown that all parts are identical, except for the tune. One place I read that the reason for the early 2006 milder tune was because the 6 spd manual trans was still offered, which was not rated for the increased horsepower of the LBZ tune. I don't know if this is accurate.

I don't know who is correct on this, other than that what I see online at diesel forums, when I google this question is that the predominant opinion seems to be that the guts of all 2006 Duramax engines are identical, except for the tune. Though there still are a lesser number of opinions that a so called 2006 LLY (going by the VIN #) is the same engine as the 2004-5 LLY.

The truck wasn't available to see today, so that is why we have an appointment to see it tomorrow. I am as yet undecided if we will buy it. Thanks again to all.
crickeydog
Explorer
Mar 02, 2014
We ordered our 2006 GMC Sierra (see sig) in late October of 2005 as soon as the LBZ engine was available for the 2006 model year and took delivery on January 8, 2006. It came equipped with the LBZ engine for which I was adamant about having. We've had some of the usual minor issues with our truck but certainly none that have required major surgery. With relatively low miles on her,(84K) we have nothing but praise for our beloved "Silver Fox". I would NEVER replace her for our primary towing duties. Many times in recent years I've been offered nearly what we paid for her.

As for an LLY. I can only speak from the experiences of two coworkers who both have the same GMC 3500 truck we have only they have 2005 models with the LLY engine. Both have experienced overheating issues that ultimately required a larger aftermarket intercooler and radiator to correct the overheating issues. From what I've read over the years, the LLY is susceptible to overheating when towing heavy loads.

I'd question if the truck you're looking at is a 2006 model with an LLY engine in it. Few LLY engines to my knowledge made their way into 2006 model GM trucks. We ordered our truck in Oct 2005 and took delivery in Jan 2006 and it was built with an LBZ engine. That was a deal breaker for me...it had to have the LBZ engine. I did not want an LLY engine.

IMHO: Find yourself a truck that has an LBZ engine in it. Good luck.

Happy camping!!! See y'all down the road!!!:)
Turtle_n_Peeps
Explorer
Mar 01, 2014
DTR, the facts you have posted are correct for the first gen LBZ, AKA second gen LLY.

The second gen LLY or the 06 LLY was the EXACT same engine minus the tune of the LBZ. They called it an LLY even though it was technically an LBZ with all of the upgrades of an LBZ.

I hope this clears things up for the OP.
Lantley
Nomad
Mar 01, 2014
Bottom line for me is pass on this truck. Find a true LBZ without all the mystery
Turtle_n_Peeps
Explorer
Mar 01, 2014
crcr wrote:
I'm shopping for a used Duramax, 06-07 LBZ. I located an 06 that seems clean and priced right, but per the VIN (8th digit is 2), it is an 06 LLY. I have read that the only difference with an 06 LLY and an 06 LBZ is the milder LLY tuning, that all engine and drive train components are identical to the LBZ, including that it should have the 6 speed Allison. Is this correct?

If this is all correct, I am still interested in this truck, and my question becomes, how much should the fact it is an 06 LLY affect the value of the truck (as opposed to an 06 LBZ)?

Second question about this truck -- It has 130K on the clock, the owner is a young guy, and he said he replaced the turbo and the head bolts at 125K. I asked why, he said his mechanic scared him telling him if the turbo blows, it will take out the engine, so he went for it, and did the head bolts at the same time. My questions are what concerns should I have about this history and this repair, and what should I look for when I go inspect the truck tomorrow?

Two questions about value/resale value:

First question: How much does this truck being an 06 LLY reduce the value of this 06 Duramax, compared to an 06 LBZ?

Second question about value: The truck has a minor dent in the rear quarter panel. The accident shows up on AutoCheck (like CarFax), and shows a rating for similar vehicles of 81-89. And it gives this truck a 74, I believe obviously because of this minor accident on the record. I am not concerned about the dent, very minor, but my question is, how much does this affect the value of the truck?

Thanks for any info!

First question= yes.

Second question= Not much if any at all. The ones that know this fact know the cost of a tune will get them an LBZ. The ones that don't know this don't care.

Third question (second for you)= depends on how good the tech was and how good of a job he did.

Fourth question= I have no idea how much a minor accident affects the value.

I do know this. The LBZ sells fast and even for crazy prices. They are very sought after. If you don't buy it soon, someone else will. If you think about this for very long you won't have to think about it at all because it will be gone.

Good luck.