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Life Expectancy of a duramax??

198326 Views 16 Replies 15 Participants Last post by  blythkd1
What is the life expectancy of a Duramax?? I saw some debate about it and that cummins had the longest life expectancy? 1+mil. miles. I have also heard that 1.2 is a viable number for d-max. Isn't it derived from the ISUZU box truck diesel??
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All I can tell you is...when I was buying a truck...I was buying a gasser...and then I saw a guy waiting for his Duramax to get done being serviced. I asked him if he liked it...and he said it was an 01 and had 537,000+ miles on it and he never had to do anything but regular maintenance. So then I went and bought one.
The Duramax is a Isuzu designed engine that is offered in the Isuzu H Series trucks which are the same as a Top-Kick or Kodiak. As far as reliability goes the only reason why everyone thinks that Cummins will out last anyone else is that the produced the 5.9l inline six for over 20yrs in different variations. I have personally seen Duramax's last 300k+ without any major problems. Try asking a Powerjoke owner if they can top that.
This is a clip from a lengthy GM Document ID #2021833

The Duramax™ 6.6L V8 Turbo Diesel Engine is sold with a warranty of 100,000 miles/160,000 kilometers. The Duramax™ has been tested to survive upwards of 200,000 miles/320,000 kilometers. The Duramax™ powertrain is designed for reliability, peak horsepower and torque within its design limits. When a customer installs a power-up device, it drastically reduces the mileage ratings.

I'm quite sure a Duramax will last as long as the engine is maintened and not mistreated.
Hey guys, I am new to diesels and looking to get one so I can start running bio diesel. In the last post it mentioned that the Duramax has a 100K mile warrenty. Does this go for all the duramax's and will the warraty be good for a second owner?

I'm pretty sure that all GM warranty's are transferable and all Duramax models have a 3yr 36K Bumper to Bumper warranty the thereafter is a 5yr 100k powertrain warranty.
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Hey guys, I am new to diesels and looking to get one so I can start running bio diesel. In the last post it mentioned that the Duramax has a 100K mile warrenty. Does this go for all the duramax's and will the warraty be good for a second owner?


I heard the warranty can be voided if you run bio...any body know for sure? I know the big diesels like Detroit, etc... has a 5% max blend of biodiesel, or they get funny about the warranty.
I mistreated mine a few times
02 2500HD, 240,000 miles, I will buy another one
hey just researching for my friend whos looking into buyin a d-max :eek:

Try asking a Powerjoke owner if they can top that.
wow, i hate how the 6.0L PSD give such a terrible rep, i love my 7.3!!! :gearjamin
unfortunately I sell fords, but I'm a chevy guy at heart. I've seen people trade in duramax's with 750k miles before and then turned around and had no issue selling them to other diesel lovers. ive never seen a 6.0 with over 200k miles that hadn't had major mechanical issues at one point in time.
I have 2012 6.6L, I love it. The one thing is that at 82,600 miles I'm changing the turbo.
Mines Over 322,000 miles and going strong.


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Mine has 208,000 on it. Hoping to keep it at least 5-6 years which will push me over the 300,000 mile mark.
I got a chuckle out of this thread. Started back in 2008 with guys raving about the 100k mile warranty and boasting about the Duramax lasting 200k, maybe even 300k miles. Wow, we've certainly came a long way since then :)
It really is a gross generalization to say the "engine" last for XXX miles. Head gaskets fail as do water pumps and AC units and front suspensions and transmissions and electrical components and of course the very expensive fuel injectors. A friend with a 2002 Duramax has had to replace the injectors twice in the past 3 years with only 25,000 miles of driving. Considering that an injector repair costs as much as a complete gas engine rebuild, the longer life of a diesel engine needs to be taken with a very large grain of salt.

What is also overlooked is that gas engines with 300,000 miles of use are also common. My brother replaced his Toyota with over 340,000 miles on the odometer because the body had rusted out from the salting of the roads where he lives. The engine and transmission were operating perfectly. When tetraethyl lead was eliminated from gasoline in the mid 1970's, engine life was more than doubled.

Taking lead out of the exhaust stream also reduced brain damage in children living near freeways and inner city traffic and when the became adults the crime rate dropped dramatically. Politicians like to take credit for the drop in crime but it was the result of taking toxic lead out of gasoline and nothing more.

It is also a mistake to talk about Cummins engines as though the same power plants in the light duty pickups are like the engines going into tractor rigs on the highways. One thing that the Cummins pickup truck engines do have is the use of much better CAT fuel filters as an OEM item.

Even with the Duramax the reliability varies by model type and production year prior to 2011 and the same is true for the Ford diesel engines with their less than stellar track record.
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Yeah I was mainly talking about post-LB7 versions, as were many of the earlier posts in this thread since it was started back in 2008 and some of the comments were about how long the warranty was. LB7 warranty was all but done with by the time this thread started, except for the extended warranty that was put on the very injectors in question. Later versions haven't had much injector trouble.

Water pumps, AC units, front suspensions, transmission and electrical components weren't even part of the discussion about the life expectancy of a Duramax.

My point was that most post-LB7 Duramax engines that have seen even average maintenance and haven't been pushed hard with mods and/or tuning will easily outlast the original posters' expectations before you can expect any major service or repairs.
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