Why does everyone dislike the 6.2 diesel?

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bigcountryguy19

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Just wondering why so many people dislike the 6.2 diesel, from my experiance with them, they last forever and get great milage. I know they are not powerful, but is that the only reason? I have never had one that broke a crank, cracked a block or lifted a head. Am I just a lucky one that has never had these problems? I am curios to hear why they are branded one of gm's bastard engines.
 

bucket

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I know lots of people that like them. I've never messed with them, other than changing an alternator or something.
 

Jims86

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Most that dont like them have either had a bad one from the get go( it happens to all makes) or have had a taste of the current benifactors of advancement in diesel technology, like Dmaxx, Cummins, or powerstroke powered trucks.
They have done well for the military in humvees for a long time.
 

woodsrider250

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...and in tons of military(CUCV) and regular ole' squares. My uncle had a 30 truck fleet of 6.2 squares back in the day and proudly exclaimed 300k out of each of them in the end...then ended up changing businesses and those are all Macks. His personal square was a 6.2 GMC K5. Also always had a Caddy, and at the time just bought a brand new 86 500SL...Ended up putting 300k on the K5 while the cars sat. Been keeping my eye out for a solid beater burb with the detroit.
 
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bigcountryguy19

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I have owned three trucks with the 6.2, and the only problems I ever had with any of them is the dang glow plugs, and on one the starter bolts ripped out of the block. But I think that was from the starter bracket not bein on. They are turds when it comes to power, but it makes up for it with fuel economy and longevity in my opinion. I get 20 mpg with my k20, I would love to see any 350 do that lol.
 

Jims86

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I have owned three trucks with the 6.2, and the only problems I ever had with any of them is the dang glow plugs, and on one the starter bolts ripped out of the block. But I think that was from the starter bracket not bein on. They are turds when it comes to power, but it makes up for it with fuel economy and longevity in my opinion. I get 20 mpg with my k20, I would love to see any 350 do that lol.

Diesels of any type, when in decent shape, will always be more efficient fuel wise, than a gasser.
 

towjoe

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I've had pretty good luck out of my trucks with the 6.2's. I have a M1028a2, a M1009, and one over in one of my K30's. they are pretty doggy, but for almost twice the milage of my big blocks there a good deal. I just pulled a mechanical non turbo 6.5 out of a 95 30 series van that was still running at 386k miles. All the rest of mine are under 80K miles tho
 

El Camino Man

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I dislike mine because its a dog and a half lol. Besides that, whats not to love! Awesome fuel mileage, cheap parts, etc etc.

Mine did have mechanical issues though. I bent a connecting rod in mine! But that wasn't the trucks fault...
 

woodsrider250

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I also remember being at my uncles and he brought a company square home with a plow on it as they were forecasting major snow....He got out and said "These things will only do 80, but they will do it with the plow down" LOL
 

83_c10

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I get the same reaction from people. Yes Detroit's are known to run away and blow up. My neighbor across the alley used to drive semi's and He hates Detroit. No power he says. Still more power then any gas engine. We both agree Cat's have power. I just plain love diesel better then gas. After all I busted my knuckles in college on them. Heck I decided to not get a degree in Automotive Technology and went for a degree in Diesel Technology. Damn good thing I did cause diesel is making it's way into american cars now.
 

Rollin_Thunder

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I had an 84 K20 with a 6.2 in it. I didn't have an issue with it at all. The PO put cherry bombs on it and made it sound like a hopped up small block that did good on mileage. I would like to find another one only a C30 this time and put a banks turbo kit on it. They did that with an uparmored HUMMV and increased power and torque (naturally) but also improved fuel mileage and take off times. I have had to rebuild a few in my old unit and it's not an overly terrible experience. Although if given the opportunity I would swap out an LB7 Duramax and Allison into a truck just for kicks and giggles.
 

FilthyFifth

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The power to weight ratio sucks and there isn't a whole lot you can do to get more power. No one really makes aftermarket parts, but fuel economy is great.
 

Jrgunn5150

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I know why i don't like mine in my CUCV Blazer. It's super slow. It's so slow I always think the parking brake is on or something. I mean, it's dangerously slow. I have to plot traffic maneuvers like I'm driving the U.S.S. Nimitz.

There's not alot I can do cost effectively to make it more reasonable.

I'm really unfamiliar with it, and how to trouble shoot it, which makes me not want to mess with it.
 

HotRodPC

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You can always add the 6.5 Turbo off of a donor 6.5 truck. That will pick up the pep a little.
 

68post

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My old '95 G20 came with an NA 6.5 with only a 3.08 rear gear , but the 4L60's first gear helped it move along pretty good off the line. It didn't like OD with all the weight it hauled unless you were at 75 mph or better, but a combined mileage avg of 18 mpg was double what I'd have had with a gas engine.

My old 2000 3500HD was 6.5 turbo and would leave you sitting at the light with the NV4500 first gear. It was 10,500 with the bed empty and I didn't check mileage often but did achieve 15 mpg (combined city & hwy) at least twice. Again..most likely double what a 454 would've achieved. Not easy in a diesel with a manual trans !

None of the Detroits were much HP , but that's not what they were conceived for.
 

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