My dad owns two Duramaxes - an 04 and an 08. They are wonderful trucks, but very low mileage. They are RV tow rigs so they get very minimal road time each year.
So I'm thinking about getting an 03 with 215k for myself. I've heard that injectors fail around 180k and injector pumps go around 225k. This owner has owned it since 165k and we don't know if injectors/pump have been done already or if I'm buying an expensive time bomb.
Anyone know how much I'm in for for parts if they die? I run a shop so I get basically free labor.
THe only thing I really know - and the sole reason I bought an '04 and a half after a bit of research... is that you have to yank the valve covers on all the LB7 and earlier models just to access an injector and all the later models get worse mileage because they piled on the emissions in '05.
So... '04 LLY is the ticket. The earlier models are supposedly pretty stout - just less power, economy and harder to work on.
disclaimer - This is all 2nd hand info and I am no expert on oil burners. I can say that so far - the advice I got was spot on with regard to the mileage I'd get and the truck is awesome in almost all regard. I'm pretty sure Chevy has not changed anything except the engine/trans so if you can clear those as decent its a solid choice.
dinger
New Reader
1/14/11 11:26 a.m.
The injectors are kind of a crapshoot. If the truck was well maintained, filled with good quality fuel, and had the filter changed regularly (like every other oil change) the injectors should have some life left in them. The other thing to check for is the material that the fuel filter on the truck is made of. It seems that the steel can filters were prone to rust (as the fuel filter is also a water separator) and the plastic ones were the way to go.
The injectors on the early Duramaxes had their warranties extended out to 8 years/200K miles, so I'd suggest running the VIN by a GMC dealer and seeing if they have any record of them being changed. If they haven't been changed, and you end up doing them, you are looking at a $1200 to $1500 parts bill, and they are kind of a pain to change on an LB7 as Snorklewacker mentioned. The thing to watch for is white smoke on cold startup. If you see that, the injector nozzles are toast, and you'll need to replace the injectors.
I've never heard of an issue with the injection pumps myself though.
I'll check as much as I can Right now its KBB value is around $12k and I'm trading him a box truck worth about $9000-10,000.
Just want to make sure I'm getting a fair trade considering the possibility of failure at its age.
One nice thing is that it already has CAI and exhaust and a Diablo tuner that only adds a modest power boost = Extra goodies and low risk of damage.
Talk to your local machine shop. They'll tell you which of those engines pay the bills. 
Keith wrote:
Talk to your local machine shop. They'll tell you which of those engines pay the bills.
I know that I've never seen an Allison tranny at my shop, but I could cover the walls with broken 47RE and 48RE parts in the trash pile here.
I would prefer the cummins if it didn't trash transmissions. Those pulses every 120 degrees kill em quick.
My perfect truck: 12v cummins in a 99-03 F250 with an Allison trans, a chevy interior, Ford electronics, and a Dana 80 rear.
But, since nobody makes that and its expensive to reproduce, I'll stick with the Dmax/Allison for now as my pick. My only other pick would be a 7.3 Powerstroke with the 6 speed.
