Hi guys, I'm new to the form and I've got some questions about buying my first Duramax that you've probably heard before. I've been looking to buy an LB7, 2002 preferable. But I know about the injector problems and the pump rub on the transfer case. Because of that, I've been kind of weary of the LB7's. What's your opinion. Should I just get an LLY or LBZ? Or should I get the truck I've always wanted and put money aside for new injectors and fix the pump rub issue? Any info that would make me feel better about buying an LB7 would be appreciated.
LB7: Should I be scared to buy an LB7
- Thread starter LB7duramaxlover94
- Start date
They all have pump rub up until 07, I would just buy one that needs injectors and swap in SAC type and roll with it. I love the 02 front end..,
Injectors are cheaper for lb7. I second what nc said. Get a set of sacs from lincoln diesel and a lift pump. That will cover your injector worrys. The pump rub can be fixed in 2 hours of your time. Merchant sells a kit with everything you need including new fluid for around 120$.
The whole injector arguement in lb7's drives me nuts. They all can lose injectors, just most lly+ owners don't want to admit there p0087 is injectors. Yes, lb7 injectors have a track record of going out more often, but sac nozzles seem to have helped this, and lb7 injectors are cheaper to buy when they do go. Buy the truck you want is how I look at it.
Just remember with an lb7 to replace return lines from injectors because they are under the valve covers and you do not know they are leaking sometimes until it is to late , that is the main thing that I would be concerned with , other than injectors .
The return line is a steel hard line. Unless it's damaged, you shouldn't need to replace it. Its not like lly+.
ive said that until blue in the face too many times, for the short time i worked for GM i did more lly+ injectors than lb7. in fact id be more inclined to say the lly+ specifically lbz/lmm injectors go out more often just not in batches of 8.
people seem to think a time consuming injector job on an lb7 means they go out all the time.
i think of lb7 injectors as a maintenance item, around 100k or so, its time to replace. the lbz/lmm injectors just fail randomly.
Just buy the truck you want. As many others have said the injector issue is pretty well squashed now with the SAC nozzle being put onto the LB7 (originally had VCO) and a good lift pump. The 01-02 body/front end is my personal favorite and there just aren't many of them left in good shape.
I've been called all kinds of stuff for saying it. Not to mention how pissed off lly+ owners get when you tell them they need injectors and the "only LB7's lose injectors" arguement. And LB7's normally only lose 1 or 2, most did all on a side or all 8 simply because of the amount of work to get to just 1.
Are the leaking problems we hear about because of cracked lines or because of not being tightened properly ?
your just trading less time for more money on a LLY over a LB7. specially if you add twins and shit.
LB7 will still always have the chance of a cup leaking or eroded away cup sealing surface if the previous owner was a retard and never fixed his "coolant leak". yes you can argue this point about threaded in cups, lly's can do that if the copper seal goes bad, etc but the chances in a LB7 are greater than a lly when buying used.
unless you sealed the top of your injector hard lines, you will get junk in the top of your injector any time you pop the hard line off vs the LLY that dont
LLY are quieter. you have more pilot injection events and yes you can quiet an lb7 down but you can still make the lly quieter. i noticed that the moment i started up my conversion.
you have the turbo brake available in just the simple change of a tune vs the LB7.
both have the likely chance of having bad HG stock BUT i feel LLY crack heads more (and thats not just cause i have a cracked one). that may be due in part to cooling issues.
the brings up the cooling issues that "could" happen on a LLY vs the fact ive never known an lb7 to have that issue till you turn it up and try pulling az grades during the summer
this could be fought which is better for days and days and in the end, they both seem to come out equal to me. When i did my swap in 2015, i needed injectors and the cost for injectors was the same for my lly swap. SAC injectors had not come out yet either. no brainer, im going LLY. i noticed the improvements right off the bat including when i stepped up to bigger injectors a year down the road and how simple it was to change them. Now i got a cracked head ill be pulling but atleast i can yank the LML hg's off and put some victor reinz on there instead. Plus it will have LBZ heads just to add to my "muttness"
if the SAC injectors will 200k like most LLY/LBZ/LMM injectors go like i see before worn out, id stick with the lb7. having to dig under the cover multiple times in a year to replace one or two injectors on a lb7 sucks ass. been there done that.
LB7 will still always have the chance of a cup leaking or eroded away cup sealing surface if the previous owner was a retard and never fixed his "coolant leak". yes you can argue this point about threaded in cups, lly's can do that if the copper seal goes bad, etc but the chances in a LB7 are greater than a lly when buying used.
unless you sealed the top of your injector hard lines, you will get junk in the top of your injector any time you pop the hard line off vs the LLY that dont
LLY are quieter. you have more pilot injection events and yes you can quiet an lb7 down but you can still make the lly quieter. i noticed that the moment i started up my conversion.
you have the turbo brake available in just the simple change of a tune vs the LB7.
both have the likely chance of having bad HG stock BUT i feel LLY crack heads more (and thats not just cause i have a cracked one). that may be due in part to cooling issues.
the brings up the cooling issues that "could" happen on a LLY vs the fact ive never known an lb7 to have that issue till you turn it up and try pulling az grades during the summer
this could be fought which is better for days and days and in the end, they both seem to come out equal to me. When i did my swap in 2015, i needed injectors and the cost for injectors was the same for my lly swap. SAC injectors had not come out yet either. no brainer, im going LLY. i noticed the improvements right off the bat including when i stepped up to bigger injectors a year down the road and how simple it was to change them. Now i got a cracked head ill be pulling but atleast i can yank the LML hg's off and put some victor reinz on there instead. Plus it will have LBZ heads just to add to my "muttness"
if the SAC injectors will 200k like most LLY/LBZ/LMM injectors go like i see before worn out, id stick with the lb7. having to dig under the cover multiple times in a year to replace one or two injectors on a lb7 sucks ass. been there done that.
usually due to poor seals used, under torqued or just not paying attention to the condition of the parts.
Good comparison post #14 , thanks I know very little about lb7s obviously , thanks !
Injector bodies cracked on early lb7 injectors. Then there is people not replacing the sealing washers when they work on them. The return line bolt heads get stripped, then can't be properly tightened. Or running too much rail pressure and the injectors crack.
Thanks for the info , this is such a great site, we could not get this kind of help from any dealership ! thanks again !
I had 350K hard miles on my LB7 and never had any real issues. I did however put a set of injectors in it right when I got it and was near 100k on them when I sold it. SAC injectors were not available when I did mine, but even factory Bosch one's worked out well.
Thanks everyone, I didn't know about the updated SAC injectors. I don't mind doing injectors on an LB7, I helped my cousin with his 02. And spending extra money for a lift pump wouldn't be a bad idea either. I was just afraid of having to replace them every 30,000 miles or so. If there is anything else you can tell me about an LB7 id like to know more. I'm starting to look around now so more info would be awesome.