the 6.5L engine overall is a great engine, there is a reason the are still producing it today. GM screwed up a couple things when hey put them in their trucks. biggest thing is PMD, but other stuff like stepper fuel pump and electronics. but I've seen these motors go over 500K, especially in the Marine applications. they are slow but have good torque and get pretty good fuel economy.
'96 and up had the better/revised module, less susceptible to under hood heat issues.
I once had one item on the injection pump that failed, local Diesel Injection shop repaired just that item on it, ran the pump on a big calibration machine they had in shop (whole room full) and reinstalled.
Listening to that machine run, you quickly realize the sounds you hear at idle are not the motor, but that pump itself.
Simple repair, 1/2 day in the shop. But the failure wasn't simple....throttle ran away on the highway, smoked out the masses, barely got over and stopped on the side of the road. Scary. :surprise:
Put over 300k miles on it.
5-spd shaker....went thru several clutches (not a good mix in stop/go traffic towing).
DRW, no speed demon (but you could break traction) not much good for towing over 10k lbs...always got 15mpg....hills, flats, towing or not....15mpg.
There were some rare 1500s that had the 6.5T, with the 3.43 gears....reports of 25mpg, kept in the families for years, passed down repeatedly to the next generation....they just ran and ran...paint faded out...ugly, but they kept running.
But the best part of that truck?
The SEATS! Comfy and built for wide glide rear ends. :smile2:
I’ve got a ‘99 k3500hd(yes, a K3500HD) bought it in Montana from a fire dept with 38,000 original miles three years ago and drove it 3050 miles back home to Maine. Truck weighs 10,000 and gets 16 mpg empty with the 5speed. I put a dump body on it and a plow.
I leave the pit weighing 20,000 lbs usually and like everyone says... she’s no speed demon but this truck has given me ZERO problems.
Best thing I did was installed a set of Bosch glow plugs. Started like it was summer time all winter long even in -10 degree blizzards. I did also replace the harmonic balancer bc I say the rubber was cracked and there was the slightest wobble to it