LB7: Looking to get an LB7

[hetzler_l33]

Afternoon,

Looked at a 02 Chevy 2500 LB7 CC/SB 2WD today and it's been well maintained as far as I can see. It's a one owner, an older gentleman according to the salesman, and the fluids check out. Trans fluid is still clear-pink and is slightly dull but it's been changed. Oil was fresh from dealer. Coolant was a little low but no soot or blow-by present. Drives smooth and shifts so good you don't know it's shifting. No mods, all stock. Only leak was some PSF moisture under the hydroboost-MC connection point but wasn't dripping or running, just wet.

Now comes my paranoid side: the infamous injectors on these LB7s. I have no idea if they've been changed at all, dealer has no idea either and the Carfax only shows the registration renewed every year. It's literally a shot in the dark. I have the VIN but who can I talk to for that kind of information?

I'd like to get your guys' reviews/experiences with the LB7 and if it's worth it. Truck has 199,850 miles and dealer is asking 13,900. Don't want to get it just to have injectors dump on me a week later.

Thanks in advance

P.S. I didn't know where to post this so move it to where it's needed

 

[apwcu]

With that many miles, if it's not smoking or has fuel in the oil there's a very good chance they have been changed. The only problem is if they were changed a long time ago maybe around 100k miles it may be time to do them again.

If everything checks out good, you may could get by a while before you see any signs of them going out. It doesn't seem to be too common that they all of a sudden go out without notice. If it's a Chevy dealer, they should be able to hook a tech2 module up to test the balance rates for you to see if they are with-in spec.

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[hetzler_l33]

With that many miles, if it's not smoking or has fuel in the oil there's a very good chance they have been changed. The only problem is if they were changed a long time ago maybe around 100k miles it may be time to do them again.

If everything checks out good, you may could get by a while before you see any signs of them going out. It doesn't seem to be too common that they all of a sudden go out without notice. If it's a Chevy dealer, they should be able to hook a tech2 module up to test the balance rates for you to see if they are with-in spec.

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No smoke from what I can tell and I tried to smell for diesel in the oil but with the new oil and my bad sinuses, it was hard to distinguish. It must have been replaced sometime like you said because it's unheard of for stock injectors to go to 200k.

It's at a used car dealership here in town. Guy didn't know anything I was asking him so I left with more questions than answers. As far as RPMs while driving, they seem to hang around 1500-2000 while cruising and 600 at idle. No jumping/skipping and picks up speed well. Normal from my experiences, no weird or unusual knock either.

Should I get someone with a tech2 to test the rates? There's a guy here who only works on diesels and ECM tuning so I'm sure he can do it. As far as physical tests, I can do them as I'm in school for diesel mechanics and I've been around medium duty diesels for a while. All I've heard about the LB7 is the injectors and other bad things.

Sounds like the LB7 is the hated stepsister

 

[duramax on fire]

I hated mine at first love it now. Of coarse that was after head gaskets and injectors lol. The best thing about these is the no emissions at all. The low coolant would bother me. Maybe the water pump starting to leak. Common at that mileage. The other down side it is a used car sales place. I hate them. There usually lying. No way I buy it without taking it to a dealer and having them do a trade in check.

 

[hetzler_l33]

I hated mine at first love it now. Of coarse that was after head gaskets and injectors lol. The best thing about these is the no emissions at all. The low coolant would bother me. Maybe the water pump starting to leak. Common at that mileage. The other down side it is a used car sales place. I hate them. There usually lying. No way I buy it without taking it to a dealer and having them do a trade in check.

That's usually how buying a used car/truck is because you don't know the state it's in until you've had it for a year or so. Yeah seeing the coolant low did bother me but also after 15 years it will probably be low if it hadn't been topped off. Are the water pumps hard to change? Or is it one of those "a lot of steps but easy to do" things?

I'm not excited about doing an injector job anytime soon. Well I don't mind the work, just having to fork up the cash lol. Does adding a lift pump help the longevity of the injectors? I understand the fuel additives, it's a necessity with diesel quality being shady at best. The salesman says they got it from a dealership but the truck has been in Coffee Springs, AL it's whole life. It's now in Tuscaloosa which is a good 4ish hour drive to Coffee Springs.

The only hint I have to injectors is the Carfax that says at 182k miles the engine was checked by a service center. Then a year or so later it was up for sale. No one knows anything about it. Can I do that though? Take it to get an inspection or get the fuel system bench tested as well as balance rates before buying it?

Thanks for the responses!

 

[zakkb787]

You need to get the balance rates tested before you buy it. If they are creeping towards out of spec then expect to change them soon. I'm not sold on additives. Just find a station that sells quality fuel and don't use Walmart fuel. As far as lift pumps, they'll aidbin keeping your cp3 happy and fuel cleaner depending on the setup but there's no real proof that it makes injector life longer. The low coolant thing bothers me too. I bought mine and said low coolant and ended up being a leaky cup. Personally. I think the price is a bit high for it being a 2wd. Just my .02

 

[DAVe3283]

My 2003 got 206,000 miles on the stock injectors. So it isn't impossible, just rare.

If the coolant has never been changed, it is probably all sorts of corroded inside the motor by now. Expect at least the water pump housing to be pitted, with possible pitting and corrosion on all the aluminum. The additive package in DexCool is only good for 5-7 years.

If it were me, I would plan on replacing the injectors and water pump immediately, and place any offer accordingly.

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[duramax on fire]

Yeah the coolant would be a done deal for me. It's going somewhere. Just saw the price. I'm thinking 9k max running great no issues. I told myself I would never buy another lb7. Even though I like mine. I really like the lbz with 6 speed auto. Also the 08s and up a few years are cheaper than the lbz. Just have to delete the dpf when it gives you fits

 

[duramax on fire]

Plus that water pump is a pain to change. Have to pull the balancer off.

 

[hetzler_l33]

13,900 is high imo but any Duramax around here that's an LLY or newer motor is at least $20k even though they're reaching into 220k miles. That's insane to pay that price for so many miles.

Anyways, I doubt they'll come down much and I was thinking of throwing 9.5k on the table. It's not that I don't want the truck since it's a critically flawed design, it's more of the financial requirements of when they go bad.

Zak, I read your thread yesterday and the only difference is the low coolant light isn't on. If you physically look at the coolant reservoir, you'll see it's maybe an inch below the full mark. I'm not saying there's nothing wrong, it's going somewhere like duramax on fire said. The work to get the things done doesn't phase me, the price for the parts does however. I smelled the reservoir and it smelled like dexcool so I'm thinking it's not super old since it still has that smell and it's clear-orange/pink. Aside from what I could see, smell, and touch, I have no idea what mechanical work has been done.

Dave, that's pretty smart to assume changing injectors and waterpump outright but I was hoping it would be decent enough to drive around for a year or so until I can save up enough to replace the injectors with the new Bosch style. The waterpump I can do, it's only a couple hundred bucks, a coolant flush, and a weekend. Injectors are an arm and both legs but the worst part is there's no guarantee it'll go another 50k miles before failing again.

But how common are injector failures really? Most people only talk about it and it's mainly on forums. The ones with good outcomes hardly go on forums and share the knowledge. Plus a lot of LB7s with injector failures have been tuned from what I've read. Maybe it's just luck?

 

[hetzler_l33]

Sorry for typing so much, just want to get all the information I can

 

[TheBac]

Wherever you're getting your information or your interpretation of it is incorrect. LB7 injectors go out no matter the truck, lift pump, additives, stock, tuned, etc. As Dave said, them going 200,000+ miles is very rare. If you cant fully check the truck before buying, then its up to you to take the risk. Assume you have to change injectors within the first year anyway, and make your offer accordingly.

 

[zakkb787]

My coolant wouldnt get super low fast at all. And you're not gonna know how fast it loses it if it is even losing it. You need to shop around more in your pricing as well

 

[hetzler_l33]

Alright, thanks for the clarification on my knowledge. I think I might pass on this one and keep searching but I'm going to limit my range to LLYs and LBZs. Their injector failure rate is a lot lower and a shorter down time.

Thank you zak for your input, how are you liking your LB7 after replacing everything?


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[Awenta]

All the other generations lose injectors just as much as lb7s. Llys maybe even more so.


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[hetzler_l33]

Fill me with knowledge, I haven't heard about as many injector failures in LLYs as in LB7s. I know the LLY has the overheating and head gaskets issue but I'm sure most of them have head gaskets go out since a lot of them were used for towing.

So am I pretty much going to have the same percent of injector failure risk in getting the LB7 vs. the LLY?

Besides the turbo changes and other changes to the LLY, am I better off getting an LB7? This will be my first diesel so something reliable that I can use as a DD for a few years without major headaches is preferable. I understand anything can happen and that it has high mileage but as far as I know it's never been used to tow large payloads. So I'm thinking it's had an easy life so far


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[zakkb787]

Alright, thanks for the clarification on my knowledge. I think I might pass on this one and keep searching but I'm going to limit my range to LLYs and LBZs. Their injector failure rate is a lot lower and a shorter down time.

Thank you zak for your input, how are you liking your LB7 after replacing everything?


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I love this truck. Granted it's got its quirks but in my opinion it's the best body style and I love the motors. I wouldn't personally trade it for any other duramax.

 

[zakkb787]

Maybe I'm wrong but I've never heard of as many of the newer generations messing up as much as an lb7. I'd love to have an LLY in addition to my lb7. But I wouldn't sell my lb7 to get one. But the LBZ and newer trans are nicer. I try to tell everyone you gotta go drive a few and get the one that you feel is right. We don't know your tastes and preferences. Only you can choose your truck perfectly. But in my opinion that much for a 2wd without any injector history is a no go.

 

[TheBac]

Look, if you realize you'll have to change injectors in the future and can do the job yourself, then an LB7 is a great engine to have. The SAC injectors are showing promise of living longer, but.....
If you go the LLY route, you'll have to deal with it's problems, too. Add an LBZ mouthpiece, clean the cooling stack of dirt and debris on a regular basis, and maybe a couple other things to deal with the possibility of overheating and away you go. Their injectors fail too, but at least you only really have to replace the ones that fail, not all. Return lines get brittle.
LBZ's, I dont have much to say. Treat any injector issue like the LLY.

Its all in what you want, what your level of mechanical expertise is, and what you're willing to do yourself.
I love my LB7s, enough so that I bought one for my little truck (or as a spare).
I would love to own an LBZ someday, but if it doesnt happen, Im fine with that, too.

 

[joshd472]

That price is too high. Also this is my opinion but a 2wd diesel is absolutely useless. I would pass on this one and shop around some more. Very good deals pop up for sale on here from members. It'd be worth the drive to get one that has a known history and has been treated right.