6.0L with 100K questions

[ThumperTDC]

I'm in the market for a new rig, and have the possibility of picking up a 2000 GMC 3/4 I believe with the 6.0L for a pretty decent price. The truck has almost 99K for milage and was curious if anyone has experience with a 6.0L with higher milage. What should I look for? Is there any real issues to be aware of? I know this truck has not been abused or even towed very much, just driven daily.

[DarylB]

It could have the cold-piston-slap/knock, which is more of an annoyance than a reliability issue.

[ThumperTDC]

Well, I bought the truck and pick it up tomorrow. I found out its a 99 not a 2000, but its still the newer body style. The thing looks and drives like it has maybe 50k on it. Now its just time to getting it set up to pull a goose neck horse trailer.

[Mark Rinker]

I did a fair amount of towing with a 2003 K3500 with the 6.0L gas engine.

It got the job done, but burnt quite a bit of gasoline in the process. My advice is "live with it - at least its cheaper than diesel fuel".

Intake, exhaust, programing modifications didn't do anything to increase mileage. Maybe a 5% increase in power. Live with it.

The 4L80E transmissions aren't too bad, make sure you keep them full of fresh fluid and keep the temps down, you should be okay. If it was a daily driver, it probably has lots of miles left. The Predator 6.0L tuner will give you firmer shifts by increasing line pressure, could help longevity if you tow alot...

[SDakDmax]

I drive a 2002. I think the 6.0 is a good engine. Like he said don't worry if you hear a little piston slap, it will run forever if you take care of it. I work for and elec./gas utility. This truck takes me out in -40 degree weather, or 115 degree weather.. works great. It gets abused plenty in my line of business. Congratulations on your new ride, I think you'll love it!!

[ThumperTDC]

I did a fair amount of towing with a 2003 K3500 with the 6.0L gas engine.

It got the job done, but burnt quite a bit of gasoline in the process. My advice is "live with it - at least its cheaper than diesel fuel".

Intake, exhaust, programing modifications didn't do anything to increase mileage. Maybe a 5% increase in power. Live with it.

My plan for the truck (since I told my wife this will be done before she starts towing the big ass horse trailer) is to install an intake, dual exhast from the cat back and I am also looking into getting a bully dog power pup programmer. From reading up on it, it sounds like the best one so far I have seen and then reprogramming it for the towing mode. Talking with the previous owner, he did once tow a trailer with a medium sized tractor on it and it did just fine, so I am not too worried about the weight from horse trail, but want alittle firmer shifting due to the miles on the rig. Thanks for the replys.