Start off with a Hello first post on this forum so cheers

I recently bought a 2000 Chev 2500 pickup 6.5TD with 196,000KMs (120k miles) the truck is in really good shape, was owned by an older guy, bought it two weeks ago. The truck doesnt smoke white or black smoke. Starts like a charm. Drives really well, engine sounds really good.

BUT! Its thirsty, incredibly thirsty. I dont get it! I filled up last week 130 liters and drove 540 kms and its bone dry! Thats like 7.8mpg or 30l/100kms! I have a 6.2 NA diesel and I can drive it for what seems to be months before I have to fill it again. I even try and never pass 2000 rpm even on the highway i keep it in and around 1500 rpm.

Things I've checked and done:

-Changed the oil replaced it with premium blue synthetic HD diesel oil
-Checked the intake filter (clean)
-Rerouted the crankcase breather to under the truck and plugged the hole in the intake
-Rear tires running 70psi and 65 psi in the front

Truck has no weight in it other then my fat a**

I had the engine codes checked got a P0236 boost control out of range (but no check engine light) The arm on the actuator doesnt budge with the truck on, all the lines look really good... Bought a boost gauge will be getting it in the truck tomorrow to see how much boost im getting...

Can that be the problem! Let me know!

 

That may just be your problem, but there are other factors to consider. You indicated that the arm on the actuator doesnt move with the truck on. Do you mean with the engine running, or with the Ign on? Also, what rear gear ratio in the rear diff, 3.73 , 4.10, or other? Is this a manual or auto trans? Is it 4x4, lifted, big aggresive tires? Check for exhaust restriction, binding brakes, fresh fuel filter(s). BTW prepare for a PMD replacement. It should be going out relatively soon.

 

With the engine running the actuator arm does not move.

Dont know the gear ratio in the diff at 60mph engines turning around 1800 rpm.

Auto trans 4x4

Truck is completely stock no big tires or lifted...

The PMD has been relocated with a heat sink.

 

P0236 Turbocharger Boost System

Is the vacuum actuated boost control system still in place or is there a turbomaster installed?
Turbomaster is a spring controlled wastegate.

With a turbomaster and excess boost you will have high fuel consumption.

Get the boost gauge installed and limit boost to 10psi if turbomaster equipped.

 

Bone stock truck, still running with the vacuum driven actuator.

 

Hey bro. Dont beat yourself up over it. Its still a decent running engine, if you dont abuse the **** out of it. It just doesnt handle high boost pressures very well. My dad had a construction business and he had a fleet of flatbed 1 ton chevy 6.5 trucks, all manual transmissions. Biggest problems were keeping clutches in them, and them pesky PMD's. The trucks also towed flatbed utility trailers with equipment, weighing roughly in the area of 4k lbs.