GMC 1/2 vs 3/4 gasser; dramatic difference?

[Crabman]

Originally Posted by Socalken

the 6.0 with twice as many miles as you have might be a bad idea....those 6.0 motors are dead at 125k you will start throwing a ton of money at it soon. I would keep what you have and add a few things to help with the power and torque. try cold air intake, tuner, exhaust to name a few....you still have low miles keep it and drive it till you can get a great deal on a Diesel

Actually the GM 6.0l has an overall track record of great reliability and longevity. Most will go 300K with proper care.

[Camper_bob]

I'm actually kind of glad I gave myself some time to make this decision (3 years to be precise). I'm really torn between the gas and diesel. LOTS of things to weigh and think about...

[Socalken]

one of my good friends is a service manager at a local dealership 4 GM.we talk all the time about different motor trans combinations. There's no way this motor goes 300,000 miles. Like I said 99% of them are dead 125,000 miles. But I'm sure there's one or two that make it that long if you baby it and don't tow with it. But I guess the exception proves the rule.

[Crabman]

Originally Posted by Socalken

one of my good friends is a service manager at a local dealership 4 GM.we talk all the time about different motor trans combinations. There's no way this motor goes 300,000 miles. Like I said 99% of them are dead 125,000 miles. But I'm sure there's one or two that make it that long if you baby it and don't tow with it. But I guess the exception proves the rule.

Your friend may be correct. But I personally know of 3 fellow commercial fisherman that have 250K+ on their 6.0 engines, and they were not babied. It also gets very good reviews on forums like this one, http://www.silveradosierra.com/ The more recent (2007-2012) 5.3 AFM equipped engines have a tendency to burn oil, and that has been a great subject of discussion there.

[Iraqvet05]

That's odd because I see a ton of 6.0s for sale well beyond 125k that are still running. I'd expect an engine from the 60s and 70s where tolerances were not as tight and the metallurgy hindering long life but not in a more modern engine. I doubt Chevy would sell so many Silverado's with the 6.0L if comsumers wouldn't expect to get more than 125k miles out of them....maybe that's why Ford stopped making the 6.0 diesel, because consumers found they had major design issues.

[Socalken]

that's the point I'm trying to make maybe I should have been clearer once these motors hit 125,000 miles they start falling apart major issues have to deal with head gasket rear main seal injectors are the number one issue. Go to these sites that you see all of these for sale with high mileage and compare them to the diesels you see for sale from Chevy with high miles no comparison its like 10 of the gas trucks for one of the diesel trucks. diesel trucks are designed to last longer because they have to be built to sustain the large amount of torque of diesel motors. That's why you will get three to five hundred thousand miles out of a diesel without blinking an eye. I have two work trucks with a Duramax both of them over 400,000 miles. No problems.