The LB7 Duramax - Reliability & Common Problems!

[@thece8702]

I can vouch for 3 of them. I had to rebuild the fuel filter housing and replace the water pump. Those weren't big money issues. Now it's time for injectors. But my original injectors lasted 20 years and 250k miles, so I consider myself pretty lucky there.

[@8020Media]

Thece - Thanks for sharing your experience and insight!

[@robertelee6712]

Replaced the injectors on mine at 280,000 miles. I studded it at the same time. I've added a lift pump and run ARCHOIL. I am at 454,000 miles currently and it runs perfectly. I have noticed my water pump started to leak. Going to change it out soon.

[@8020Media]

R - Nice! Sounds like you take great care of it. Crazy what great maintenance can do. Thanks for taking the time to share your experience.

[@robertelee6712]

@@8020Media Maintenance is key. If you own a diesel, I highly recommend trying ARCHOIL. I own a construction company and it keeps my equipment running smoothly. I have backhoes that have DPF on them. They rarely regen and fuel consumption has drastically been lowered. This stuff is a miracle in a bottle.

[@billfincher8519]

I ordered my 03 new..370K on the dial, which has been a great truck. Stock- well-maintained. Installed quality injectors 250K ago no issues. Lift pump, big trans cooler. Never has run hot, tow heavy no prob. California truck with EGR-etc. Straight 5 inch exhaust. Knock on wood

[@8020Media]

Bill - Thanks for sharing your experience! Sounds like you've got a great build and have gotten great use out of it.

[@caseyclayholcomb]

My injectors were replaced once already. Replaced mine about 1000 miles ago so 3rd set soo far at 319,500 miles. Rebuilt the fuel filter housing, still haven’t needed to replace the water pump yet, she’s been a great one soo far! (All Stock Components)

[@8020Media]

C - Nice! Sounds like you've got a good one. Thanks for sharing your experience.

[@TopNotchPropertyServiceLLC]

I want an lb7 2004 so bad. Im going to plow with a boss 8,2” poly v plow. Put a dumper dogg 6ft dump insert in it for various landscape work such as mulch, dirt, cleanup debree/ brush and leaves/sticks. It will be lifted about 4-6” and be so awesome for the business. Luckily I’m a mechanic so I can do most of the work like injectors, head gaskets and stuff. It will be a learning curve to work on deisels but im set on getting this truck ive waited 7 years wanting one so I know its the one for me someday! Great video!

[@8020Media]

T - Thanks for the feedback! We love a good LB7.

[@sawyerkovis]

Good video thank you!! I just bought a 2003 LB7 and just wanted to know more about it. Good video thank you.

[@8020Media]

Sawyer - Thanks for the feedback! We love a good LB7

[@dant4917]

LB7 California edition has emissions. Cat, EGR, intake heater, vacuum pump and sensors etc.

[@8020Media]

Thanks for the note - we've never owned one of the Cali emissions ones being from Texas!

[@dant4917]

@8020 Media I wish I did my homework before purchasing. It was pricey and time-consuming to get rid of it all but was worth it. Still a great truck after all these years. 👍

[@nono-fn3zc]

Not only did the CA have a cat and EGR, but there were 2 other emissions packages that did too; NE Emissions package and Clean Fleet. If you want to be sure that you’re getting a truck that was not deleted and never had emissions, then look at the glove box RPO Codes and find FE9. If it has YF5, VCL, or NE1 it had emissions equipment from GM. Waterpump doesn’t need to be welded; use the updated one with plastic impeller. Overheating - routinely clean the stack. The rad and intercooler pack up with debris. Trans - lb7 trans can’t handle much more power than stock without rebuilding. Even 75-90hp tunes will fry one easily. But once addressed, the lb7 is great for big power over the lbz mentioned because the tuning is easier. No mention of the dash cluster or the pump rub either. No mention of the common tow haul button fails. It should also be said that using SAC injectors are the way to go when the OEM have failed. Hmm. This video was disappointing.

[@8020Media]

No no - Thanks for taking the time to write this information! It will certainly help future viewers.

[@justinreinke6929]

I have a 2002 that is at 475,000 no mods other than a stack runs fine

[@8020Media]

Justin - Sick! Thanks for sharing your experience.

[@leo1lewy2kerrs]

Thinking of getting my first Duramax 6.6 twin, 02 4x4 lbf and Allison. Its 2024 and only 183k mi ... Very clean body and interior but leaks all underneath. Hoping not rear main. Previous owner of 10 yrs put only 10k mi. Front bearings, balls, and tie rods are prob original. Concerns are injectors and rear main. My "test drive" consisted of 700mi trip towing a jeep on trailer without any issue overheating, power loss, ect. Mpg sadly maybe 8-10, flat ground Florida. Price $12k ... Suggestions on where to begin?

[@8020Media]

L - Idk if you want it if it's leaking all over underneath. Guessing you meant 2004?

[@jsterling79]

So I have a 2002 LB7 and I tow toy huller and it heats up would it be worth to change transmission oil pan to PPE so I upgraded the radiator transmission cooler to bigger when transmission start to come up truck get hot faster you have any idea for me to keep transmission cooler when towing if not towing never get hot thanks

[@8020Media]

Upgraded oil pan that has some good cooling fins inside it would be helpful. Transmission tuning should also help a bit if you have EFI Live or HP Tuners already

[@steevennunez4801]

Interesting I just bought an old man 1 owner lb7 400,300 original miles super clean, it’s only got a CAT filter adapter on it, people say to run fuel additives. Should I ?

[@8020Media]

Steve - Nice! Sounds like you've got a good one. You can, we're not going to give recommendations.

[@salramos3rd]

I ran hot shot for a while in mine, cleaned things up a bit but after I put in my air dog lift pump I got better throttle response and the turbo got a bit louder 250k miles on my ‘03 8” lift on 37x13.5 20x12

[@matthew_409]

How do I know when my truck will over heat?

[@8020Media]

There really isn't any way of knowing when it will overheat per se. The LB7 tends to overheat when the fan or water pump fail. The fan is typically the biggest issue so you can upgrade the fan clutch with something like this that is not a bad idea considering it's pretty cheap. Just keep an eye on engine temps. kbdieselperformance.com/Upgraded-Fan-Clutch-for-2001-10-6-6l-Duramax-LB7-LLY-LBZ-LMM-Chevy-GMC-2500-3500-p239040792

[@rooster72886]

I own a 2003 i just add a lift pump help prolong the injectors and cp3 pump and dont tune a stock duramax they can handle 550hp on stock internals and stick with bosch they love thay stuff but for most common issues i havent had em because i take care of my stuff lol but thats just my opinion

[@8020Media]

Rooster - Thanks for sharing your experience! This will certainly help future viewers.

[@rooster72886]

@@8020Media no worries thank you for having this informative video all diesels are good and reliable just depends what you do to said engine before building the transmission and internals up to handle it all

[@8020Media]

Rooster - Couldn't agree more!

[@jordanseguin8563]

I just bought a 2002 lb7 that is bone stock no exhaust or tune done to it with 225k what should I do other than an exhaust? I don’t want to tune it much just a mild 60hp tune most likely

[@8020Media]

Jordan - I think this would be of use to you. It's an article we have written on our Chevy Trucks website regarding LB7 mods: chevytrucks.org/duramax-lb7-performance-upgrades-mods/

[@gooddaytothrive5870]

​@8020Media I've been wanting to modify my 03 Lb7, I don't want to go too berserk, I was thinking about 15 over injectors, as it may not require a tune. Would you still recommend a tune and would it increase horsepower, or would you recommend just going with 30 over and a tune? Thank you. Great channel!!

[@8020Media]

G - Thanks for the feedback! We have a video specifically for LB7 mods that we think would help a lot: kzbin.info/www/bejne/qYnCY6Kcq8ZoZsk

[@gooddaytothrive5870]

@@8020Media great info thank you!

[@raygood7986]

Is the lb7 actually good for heavy towing ??

[@Brettclarke44]

Nope. Pushed a head gasket on mine.

[@8020Media]

Ray - Certainly not the best for heavy towing.

[@8020Media]

BCFab - So sorry to hear this... Thanks for sharing your experience though.

[@raygood7986]

@@8020Media what is the best fr heavy towing... and what's the max you recommend towing with the lb7.. i bought my lb7 because i thought i could tow with it since its a diesel .... like loads of heavy dirt and rocks

[@matthew_409]

What would you suggest I do first when I buy a lb7?

[@8020Media]

Hey Matthew - I'd suggest checking out these two articles below. First step is always maintenance and addressing any existing problems. If everything is working properly - no leaks, injectors flow well, engine fan works, etc. then there really isn't much to actually fix, just important that you know what the problem areas are with this truck in case something does go wrong. If you want a little extra performance but don't want to sacrifice reliability then drop an intake in it and run a modest tune. Downpipe and exhaust will help keep EGTs lower while towing. Can drop a bigger intercooler and upgraded radiator into it but it gets expensive. chevytrucks.org/duramax-lb7-performance-upgrades-mods/ chevytrucks.org/duramax-lb7-engine-problems/

[@awesomefish100]

Pump rub upgrade if you have 4x4

[@bannana6290]

filter housing fuel heater will rust

[@8020Media]

Bannana - Thanks for the insight!

[@youngeagle1793]

My 2003 LV7 2500 HD Duramax Allison. runs like a Cadillac. My 2000 ram Cumins 2500 like a beast specially with the Manual.

[@8020Media]

Eagle - Thanks for sharing your experience!

[@dustinbronk2311]

Only federal lb7 don't have egr. Cali does. Block off plate. Solved

[@8020Media]

Dustin - Thanks for this insight!

[@bannana6290]

pre emissions .

[@8020Media]

Bannana - Thanks for the insight!

[@mroberts4847]

Duramax are just junk

[@8020Media]

M - Well that's just not true now is it..

[@uriahhershberger-fl3pd]

you must have never owned one

[@SassyMudTruckDegenerateDumbFk]

We have 320k on ours never did injectors just a lift pump all it does is haul a mud truck up and down NY hills and still is strong as when it was 2009 bought.

[@8020Media]

Sassy - Thanks for sharing your experience!

[@Dingthedingbat]

100,000 - 150,000 is twice what the average car or truck can go

[@8020Media]

Danny - Not true at all.. Are you saying the average car truck can only make it to 50k-75k miles?