I am trying to buy an 03 Quad Cab 2500 heavy duty truck with the 5.9 Cummins diesel and auto trans and 144,000 miles. It appears to be stock with no know modifications. My only experience with diesels has been a 6.5 chevy diesel.

What should I be most wary of on this 03?

What knid of fuel economy (range) should I expect?

Anything else?

Thanks

 

I have the SO version with 170,000 on it purchased with 134,000 have had no problems I have changed brakes, oil and diff fluid. it runs perfectly.
Previous owner had a chip and added boost and EGT gauges. So far have not noticed any problems linked to chip.

 

Theone thing I do with just about every truck I buy is to go through and change the engine oil as well as the front and rear oil. And then check on the trans fluid. There's really no good way to tell how good someone has been to the truck previously and those three places are where people tend to slack off. I'm not 100% sure, but I think that in '03 your truck still had a lift pump. So you might want to get your fuel pressure to the injector pump checked.

 

the only real problem would be the lift pump. . .but you can run that 03 untill it dies and not have to worry abouthurting the CP3 pump.

as far as mileage, auto and 3.73's I wouldnt be surprized if you averaged the low 20's. 4.10's would give you around 18+

 

What is the SO version?

 

there was a Standard Output(SO) engine and a High Output(HO) then the California engine(Cali) for 03 the HO was 305hp, the SO was 285(I think) and the Cali version was only 245hp.