Duramax questions

I am looking at a Duramax with 203k miles on it. Never been tuned. It is bone stock. Very clean and well kept truck. What are some things I should look for? How long do stock injectors typically last? I know they are expensive to replace. It is a 2009 with the LMM motor.

LMM is a good strong motor, most common problem would be Glow plugs going bad. With 203k you have to understand that components are going to break eventually, unfortunately there is no way to know when they will fail. If you don't have the money to service it I'd suggest looking for one with lower miles, Diesels aren't cheap to service nor are the parts cheap. I'm a GM Master Technician and I am my dealers only Diesel Tech, we dnt see too many issues with the Durmax that has been left alone. Most common issues for any diesel would be Injection pump, Turbo, injectors, Glow plugs, EGR Valve or cooler getting clogged, diesel particulate Filter (DPF) getting clogged, and of course the Engine & Transmission control modules. Biggest Issue we see would be fuel related (injectors or the injection pump), this is usually due to customers purchasing poor quality diesel fuel, letting the truck sit for extended periods of time without adding an algicide to the fuel in the tank, and Lastly would be filtration. A lot of people are using cheap fuel filters, not changing the filter regularly. I always suggest to customers adding a quality aftermarket lift pump with dual filters/water separator. This will give you added insurance to help extend the life of the injection pump & injectors. I personally run a FASS Lift Pump on my diesel.

Honestly 203k miles is a fair amount of miles on a diesel, but if serviced regularly and not abused they can last well over 300k without major issues or longer. Key is preventive maintenance and Regular maintenance, this is key with any vehicle honestly.

Or get something with a 7.3.

Thanks for the reply. I understand with that many miles components are going to need to be replaced. Just trying to weigh my options.

I actually just sold my 7.3 this afternoon. It was a good truck but I want something newer that will ride better.

I have heard injectors are a 150 to 200 thousand miles item

But I hear a lot of stuff

I have heard that too. I am leaning towards a 1500 gas now because they can tow up to 10k and the most I will move is 8k and thats 5 or 6 times a year.

cr00241 said:

I have heard that too. I am leaning towards a 1500 gas now because they can tow up to 10k and the most I will move is 8k and thats 5 or 6 times a year.

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That falls in the category of just because you can,,,,, doesn't mean you should,,,, 8K is way too much to tow with any of the 1500 series drivetrains, unless you want to replace a transmission prematurely. It will pull it, sure, but not without causing excessive wear and tear.

OP, I would look for a truck with less mileage. Personally, I am leery about buying any vehicle over 100,000 miles, unless I knew the past history on it, and how it was cared for.

On gas vs diesel, I prefer a gas engine for my needs. It's easier, cheaper to maintain, and not as noisy. I only tow moderate to heavier loads a few times a year, and otherwise mostly my atv to the hunting club.

As far as 1500 vs 2500, I've owned multiple of both, and currently own a 2500HD. The 1500 is a tough truck, and capable of doing moderate towing. I used to tow loads 8000-9000 lbs, even gooseneck horse trailers, out of state, but it always felt a little marginal. I never had any safety incidents, or mechanical problems, such as transmission, but I was probably pushing the limits on both. I also traded trucks just before I hit the 100,000 mile mark.

My last two trucks, have been 2500 series, and honestly, I'd recommend going that route to tow loads 8000 or more, if you travel any amount of distance, and more than just a few times a year. It just tows so much better, safer, and built to tow.

For your use, a 2500 HD, with the 6.0 gas engine, would work fine. The previous body style, 2007-2014 is a great choice, as well as the 2015-2017 new body style.

The 1500 is a tough truck, and capable of doing moderate towing. I used to tow loads 8000-9000 lbs, even gooseneck horse trailers, out of state, but it always felt a little marginal. I never had any safety incidents, or mechanical problems, such as transmission, but I was probably pushing the limits on both.

That's the point I was trying to make, as an automotive tech that specializes in transmissions, I know what the internals of the different units are capable of handling, the units in the 1500 series are the same basic units they put in light duty vehicles such as the trailblazers, even cars like a caprice back a few years ago, Will the drivetrain pull those weights? sure ! Will it pull those weights without being stressed beyond its design limits? NO ,, The newer 1500 series are running 6L80e's instead of the older 4L60/70e series, but even then the clutch capacity and programming isn't designed to haul those weights. The manufacturer doesn't care if you have to replace a transmission prematurely because you towed a heavy load more times than you really should , they only want to sell the vehicle, so they advertise tow capacities that are at the limit of what the vehicles "can" tow, but pin them down and they don't recommend it, they will admit that you really should have a heavier built vehicle.
The 2500 series with a 4L80e trans or the 6L90e trans is fully capable of towing weights in the 8K to 10K range, as well as the other components of the suspension are built to handle those type of loads, ie, front end components, sway bars, springs,

I went 3/4 ton about four years ago and will never go back.
I went diesel two years ago and will have to see significant changes in gas to go back.

Everything is safer with an HD and a trailer over 4,000 lbs. Easier and better in every way.

I currently have a Silverado 1500 I've had for a few years, Z71, 5.3 with the 4L60e trans, 3.73 rear end. My previous camper was about 24ft, older model, loaded with gear weighed around 3500 give or take, the Silverado struggled towing it up to Cherokee NC, fuel mileage was terrible. My previous truck before that was a 96 F250 with the 7.3, couldn't tell the camper was back there hardly, got better fuel mileage towing with the 7.3 also.
I still have the Silverado, but just bought a low mileage (200k) F350 crew cab with the 7.3, I'll be keeping this one, the Silverado will find a new home soon, hopefully diesel won't go back to $4.00 a gallon again ,,, If you're going to tow over 5,000lbs on any sort of a regular basis, you shouldn't be doing it with a half ton series truck, they just aren't built for it. That's just my opinion of course, but it comes from a Master tech background, working on drivetrains for over 30yrs.

transfixer said:

The 1500 is a tough truck, and capable of doing moderate towing. I used to tow loads 8000-9000 lbs, even gooseneck horse trailers, out of state, but it always felt a little marginal. I never had any safety incidents, or mechanical problems, such as transmission, but I was probably pushing the limits on both.

That's the point I was trying to make, as an automotive tech that specializes in transmissions, I know what the internals of the different units are capable of handling, the units in the 1500 series are the same basic units they put in light duty vehicles such as the trailblazers, even cars like a caprice back a few years ago, Will the drivetrain pull those weights? sure ! Will it pull those weights without being stressed beyond its design limits? NO ,, The newer 1500 series are running 6L80e's instead of the older 4L60/70e series, but even then the clutch capacity and programming isn't designed to haul those weights. The manufacturer doesn't care if you have to replace a transmission prematurely because you towed a heavy load more times than you really should , they only want to sell the vehicle, so they advertise tow capacities that are at the limit of what the vehicles "can" tow, but pin them down and they don't recommend it, they will admit that you really should have a heavier built vehicle.
The 2500 series with a 4L80e trans or the 6L90e trans is fully capable of towing weights in the 8K to 10K range, as well as the other components of the suspension are built to handle those type of loads, ie, front end components, sway bars, springs,

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Yes, I agree with what you stated in the other post, and this one as well. The manufactures do want to sell trucks, and they know the 1500(1/2 ton series) is their biggest seller, so they boast about engine horsepower, and towing capacity, even advertising up to 12,000 lbs, but it's really misleading.

I had 3 Z71's and they were great trucks! I did everything I wanted with them, and towed light to moderate loads ok, but you could tell things were always marginal, with the heavier loads. I got away with it, but it's really not the best practice, and not what I'd recommend.

When I sold my last 1/2 ton, I went with the 2500HD. I don't tow heavy that often, but my tractor, bush hog, and trailer probably weigh about 10,000 lbs, and I tow that to the hunting club 5-6 times a year.

I also tow, a moderate weight boat to marshes, near the gulf, 3 hours one way, a few times a year as well. At this point, I don't ever see going back to a 1/2 ton.

Like you say, the 1500 can pull the weight, but the suspension isn't there to back it up. The entire drive train is marginal, when you exceed moderate weights. Even though the engines, boast about horsepower, most now are made light, with aluminum blocks, and really not designed to work continuously under that kind of load, and compensate for that sort of heat.

The 6.2 engine in the 1500, advertises more horsepower, than the 6.0, in the 2500, but you don't see them putting it in the 2500HD, because it's not made to be a workhorse like the 6.0. The 6.0 has a cast iron block, made heavy duty, and designed for fleet service, and low maintenance. It doesn't drop down to 4 cylinders on the highway, like the 5.3, and the 6.2. Also, it only takes 6 quarts of oil, compared to 8 or 9 like the 1/2 ton engines, making it ideal for fleet use.

Bottom line, OP, I'd opt for a 3/4 ton truck, and with either gas or diesel, would work fine. Personally, I think the 6.0 gas is all you need, but can't knock the diesel, if that's the way you go.

Bottom line, OP, I'd opt for a 3/4 ton truck, and with either gas or diesel, would work fine. Personally, I think the 6.0 gas is all you need, but can't knock the diesel, if that's the way you go.

I agree , the 6.0 is a fine engine, with plenty of torque and power, the only drawback for my use is the fuel mileage they get, but if its main use is when you're towing something , that's not as big a concern. The newer diesels are more complicated, require more maintenance in most cases, and due to government regulations have lost a lot of their advantages they used to have. I don't care for most of them, although the Dodge/Cummings engines are still good with awesome torque and good fuel mileage numbers. I've always been a fan of the 7.3 engine, and even though its outdated by todays technology standards, its a workhorse that lasts a very long time, with the benefits of good fuel mileage if treated right. That's the main reason I chose to get another one, but ones without a ton of miles and not mistreated are getting extremely hard to find.

Thanks for all the replies. My 7.3 only had 181k and it was a work horse but I wanted something newer that rode better and I do like all the new features.

I should have said the tractor stays at my father-in-laws farm and to my land is only 12miles. I will usually only need the tractor down there 4-5 times a year to cut the roads and plant.

I will never be on the interstate going 75 pulling any load heavier then my 6x12 trailer with a four-wheeler. For the most part I will not be hauling anything with it because I keep all my stuff at his farm and do not take it home with me.

I do like the convenience of a big truck with a diesel just in case I ever need to pull something heavy but I cant justify the cost of a newer diesel. Anything in my price range I see is high mileage or has been tuned, chip, EFI live, etc. Those trucks have been dogged out and they are selling them off to not pay for all the high price repairs coming.

I have looked at the gas 6.0 but I read where they only average 12mpg. That's too low for everyday driving for me.

cr00241 said:

I do like the convenience of a big truck with a diesel just in case I ever need to pull something heavy but I cant justify the cost of a newer diesel. Anything in my price range I see is high mileage or has been tuned, chip, EFI live, etc. Those trucks have been dogged out and they are selling them off to not pay for all the high price repairs coming.

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Not always true. My '02 Silverado has been custom tuned, K&N FIPK, longtube headers with off-road Y pipe plus a MagnaFlow catback, and has a level 3 4L60E that was tailor built toward me towing my 19ft Stratos bass boat...that I pulled maybe 3 times before I sold it. It pulled that boat VERY well. Barely knew it was there.

Truck has been virtually 'babied'. I get 20 mpg on the hwy and 18 around town. Got 175K miles on it and people that know me always say they want to be the 1st to know if I want to sell it.

You can look at a modified truck and tell whether it's been dogged for the most part. Some have, but not all have.