My 2003 duramax 4x4. One ton crew, is a very nice truck. But iI am having trouble pulling my Eagle lite in the Rockey mountains. Last year motor tried to get hot. This year I installed an EGT gauge, had trouble keeping below 1300. Finely my transmission got hot and puked. I really like this truck it only has 115000 miles but I just don't trust it any more. I told my wife while waiting for the transmission to cool off I was going to jack up the radiator cap and drive a new truck under it. She said good.How much better are the new 1 tons 2014 2015 2016 than the 2003? Are they worth the 25-30k difference?How does the power compare? 03 pulls ok on the flatland.

Duramax overheats are usually a dirty cooling stack. Crud builds up between rads and intercooler. Have to be separated and washed clean. Trans overheat is likely due to over filled. New trucks are better of course.

A buddy of mine with an '02 F250 is going thru the same kind of thing as you. 200,000 miles, the truck is not wore out, but is having A LOT of age related issues. He loves it and is determined to keep it, but he's no mechanic and between what he has been offered and what he's poured into it in just the last year would pay for more than half of a new one. I have a 2016 3500HD and feel the power, fit and finish, and upgrades are light years ahead of yours. 97 more HP and 245 lb-ft. more torque. A 6 speed tranny vs 5(?) speed, exhaust brake (an incredibly wonderful thing) stronger frame,bigger brakes and wheels. I pull a 14,000 lb fith wheel and the truck does not struggle. At all. Don't mean to demean the older trucks at all,but my opinion is, if you can afford it, get a newer one. And there are several small upgrades done over the model years you mentioned, so get as new as you can.

Keep in mind you have to deal with DEF on the newer trucks....Check the fuel economy ratings too. More power consumes more fuel.

mamasmax wrote:A buddy of mine with an '02 F250 is going thru the same kind of thing as you. 200,000 miles, the truck is not wore out, but is having A LOT of age related issues. He loves it and is determined to keep it, but he's no mechanic and between what he has been offered and what he's poured into it in just the last year would pay for more than half of a new one. I have a 2016 3500HD and feel the power, fit and finish, and upgrades are light years ahead of yours. 97 more HP and 245 lb-ft. more torque. A 6 speed tranny vs 5(?) speed, exhaust brake (an incredibly wonderful thing) stronger frame,bigger brakes and wheels. I pull a 14,000 lb fith wheel and the truck does not struggle. At all. Don't mean to demean the older trucks at all,but my opinion is, if you can afford it, get a newer one. And there are several small upgrades done over the model years you mentioned, so get as new as you can.Must agree with this gent. Though mine is a '13, and is minus some of the tech-y type things like on board wi-fy, DEF level gauge, newer interior and just little niceties like that, I just think the new trucks are amazing. New trucks have their issues too, but I prefer to move forward rather than stay in the old days.........except for my dirt bike......still love 2 strokes!

I use about a gallon of DEF per 1000 miles. When the warning comes on I go to WalMart and grab a 2.5 gallon jug for $12 and I'm good to go. Pretty much a non issue. My truck is a CCLB, weighs 8000 lbs. and i easily get 18-20 mpg empty and 10-11 towing on flat ground. If that is a fuel economy penalty over the older trucks,I'll take the power.

2003 duramax vs 2015 dmax | Good Sam Community

N-Trouble
Explorer
Sep 10, 2017
Ralph Cramden wrote:
N-Trouble wrote:
There is a lot more to the 2015 than just a stronger motor. Frame, brakes, axles, pretty much everything under the cab was beefed up considerably in 2011. And dont forget the exhaust brake.

Yes sir, and since the OP is comparing a 15 to an 03 its a huge difference. They went through a major generational change of everything you mention in 07. Hence the 07 Silverado and 07 Silverado Classic.

I have the gasser but the meat and potatoes under the 2015 is impressive.

No, the big chassis/drivetrain changes ocurred in 2011. 2007 brought a new body but the frame/chassis remained pretty much unchanged
ksss
Explorer
Sep 09, 2017
The newer 2015 HD's are great towing trucks. I had an 03 and loved it as well, got the best mileage of any of my Duramax trucks. However the heavier you tow the more you can appreciate what these new trucks are capable of. The much better brakes, exhaust brake, better suspension and more comfortable interior all make for a much better towing experience. DEF is really a nonissue. I am upgrading my '15 and ordering an '18 this week, should be here the end of November.
ksss
Explorer
Sep 09, 2017
Paul Clancy wrote:
Duramax overheats are usually a dirty cooling stack. Crud builds up between rads and intercooler. Have to be separated and washed clean. Trans overheat is likely due to over filled. New trucks are better of course.

Spot on, had it happen numerous times over the years.
ktmrfs
Explorer II
Sep 09, 2017
we went from an 04LLY to a 2015. In ten years they made a huge number of improvements in the drivetrain, creature comfort and noise levels. 04 fan would run quite a bit and you KNEW it was running. never overheated, but would kick in on hills. Not so on the 15. 04 went to our son, love the 15. the only things I don't like about the 15 is that it is 2 inches higher off the ground, makes getting in and out more difficult. on the 04 didn't need to use the running boards, on the 15 I do. And the 04 hood was sloped more so it was easier to see directly in front.

And the 15 gets a couple mpg better on the highway non towing than the 04 did. towing and in town is about the same for the 04 and 15.
Ralph_Cramden
Explorer II
Sep 09, 2017
N-Trouble wrote:
There is a lot more to the 2015 than just a stronger motor. Frame, brakes, axles, pretty much everything under the cab was beefed up considerably in 2011. And dont forget the exhaust brake.

Yes sir, and since the OP is comparing a 15 to an 03 its a huge difference. They went through a major generational change of everything you mention in 07. Hence the 07 Silverado and 07 Silverado Classic.

I have the gasser but the meat and potatoes under the 2015 is impressive.
True_temper
Explorer
Sep 09, 2017
Bought a 2015 chev 3500 duramax 4x4 crewcab 35,000 miles. That should do the trick.
Passin_Thru
Explorer
Sep 03, 2017
ll my friends say new trucks are trashy and spend a lot of time in the shop. One of my friends calls his the Shop Queen. LBZ is the best engine. DPF is Urea, Urea heated turns to Ammonia, Ammonia when it enters the lungs turns to crystal so when you follow a Newer MH just think!
N-Trouble
Explorer
Sep 03, 2017
There is a lot more to the 2015 than just a stronger motor. Frame, brakes, axles, pretty much everything under the cab was beefed up considerably in 2011. And dont forget the exhaust brake.
Grit_dog
Navigator
Sep 02, 2017
True temper wrote:
freewayrandy wrote:
Have you had issues with your injectors yet?

No not yet that's another concern. Paying cash, never borrow money for toys.

Not ALL injectors were bad and likely you got a good set. I seem to have lucked out on my 02 back then. Either way whether it's tomorrow or 100k from now, it's a real thing and add in that potential cost into your decision probably more than others.

The other thing is we have no idea how well you maintinaed the truck, what "trans puked" means or did to your otherwise typically rock solid trans.

How much better a LML is vs yours? If you're stock, not tuned, the LML will be a huge upgrade in power. Obviously it's a newer nicer, newer chassis and truck.
True_temper
Explorer
Sep 02, 2017
freewayrandy wrote:
Have you had issues with your injectors yet?

No not yet that's another concern. Paying cash, never borrow money for toys.