Concerns about purchasing GM Diesel Truck

Me Again wrote:

ksss wrote:

Wild Card wrote:
I would be concerned about purchasing a GM truck as well. They do ride nice though

I would love to hear what your concerns are?

Goes right along with not wanting a 6.0 or 6.4 Ford, another 47RE/48RE RAM tranny, 6.7 RAM until 2013+, or a LLY Duramax.

Comparing a pre 2013 6.7 or LLY Duramax to the 6.0 and 6.4 is beyond ridiculous.

The LLYs do have some overheating concerns, which interesting enough seem more prevalent on stock trucks than tuned trucks. But the biggest concern with ANY 2001 through early 2006 Model year duramax is the headgaskets. This isn't a crazy design flaw like the 6.0 Fords, but the early design gasket GM used was prone to fail.

As far as dealers go, no matter much you trust your dealer, GM dealers are VERY hit or miss when it comes to Duramax service. I'd do some digging locally before I coughed up $250 to have a dealer do a check up.

In your budget you should be able to get into an LMM or LBZ with some dilligent shopping. If you don't gambling on the HG with the LLY, they aren't bad trucks at all, the 6 speed trans in the 06 up is nice, but you may not see 6th gear often enough for it to be worthwhile.

LLY, LBZ or LMM can all be easily upgraded with tuning or other aftermarket devices to have a turbo brake. Which once you've used, you'll never want to go with out.

I agree on the headgaskets, that is an easy test that any tech should be able to accomplish. The LLY overheating issues are a simple fix. Certainly nothing compared to the issues with the 6.0/6.4. I had my 06 LBZ tuned for an exhaust brake and it is great, not as effective as what is in the newer trucks but effective never the less.

ksss wrote:
I agree on the headgaskets, that is an easy test that any tech should be able to accomplish. The LLY overheating issues are a simple fix. Certainly nothing compared to the issues with the 6.0/6.4. I had my 06 LBZ tuned for an exhaust brake and it is great, not as effective as what is in the newer trucks but effective never the less.

I would disagree with it being less effective than the newer stuff, other than the difference in functionality as far as being able to use it without being in Tow/Haul on the 2011 up trucks.

As far as "testing" the headgaskets, its fine and well if they are still good, but the problem in every truck built up to 12/05 have the old style gasket that will eventually fail.

I have an 05 LLY and at 134k the HGs are fine. There are plenty out there that haven't blown regardless of their build date. But, never say never.

That said, GM cranked up the power and didn't increase the cooling. They will over heat if you tow heavy going up 6-8%+ grades in 100+ temp. I added the secondary radiator and it solved the problem. Nothing short of that will fix the problem. Flat ground is fine without it but start climbing where you can't go fast and keep a good flow over the radiator and they will heat up. If you can get some speed like above 30 MPH it helps since you have air moving through the cooling radiator, but when you have to go slow so you don't die going over cliff they you are dependent only on the radiator and fan and they aren't big enough. The LLY needs more cooling. I have both Ron Davis primary and secondary radiator (E837.)

I love my LLY. Tow beast.

2005 Chevy Silverado 3500LT SRW D/A CC/LB LLY 4x4 (loaded)
LBZ MP, TxCAI, Stack sealing, Mass/IAT shield, LML manifold
Edge Insight CTS/EGT/EOT
E837 HD Radiator w/EOC + E837 Secondary Cooling Radiator w/fan, factory air dam
Earl's trans cooler, Longs Power Steering Cooler
GM Severe Duty brake rotors (SD suffix)
NuWa Hitchhiker II LS 29.5LKTG 5th Wheel (11klbs)

I would look for an 06 or newer Duramax. The 06 gained a 6 speed transmission. In 07 the body was updated. Then in 08 - 2010 DPF was added which didn't really cause a lot of issues or hurt the fuel economy that much. In '11 DEF was added which I think is a plus over the 08-2010.I think the exhaust brake was added on 2011 as well.

Head gasket issues, overheating issues, or other issues is way overblown by those who do NOT own or have owned a 2001 thru 2005 GM Duramax. I'm a retired 39 year automotive engineer and engineering business owner having worked closely hands on with Ford, GM, and Chrysler on components for Pickups, Vans, and SUV design, engineering, testing, and reliability certifications.

So much false unsubstantiated propaganda bull has been written abut these issues mostly by those with a pointed or vehicle brand agenda. GM warranty documents show less than 2% of the LLY owners had claimed or reported LLY overheating as of 2016, 12 years after the LLY was first sold in 2004 mid-year. 3.1% claimed or reported head gasket issues during the same time period. Less than reported on Ford diesels and on a par with Dodge/Ram Cummins.

My own experience:

I personally can verify my 2004.5 LLY Duramax only been used for RV use pulling our 12,840 lb scale weighed Carriage 5th wheel or the 11'4" Lance TC and often pulling a 2150 lb boat behind since truck was ordered new and received in March 2004 and now has 207,131.8 miles on the odometer presently. It's strictly OEM stock and has never overheated pulling the 5th wheel even in the western mountains passes/roads at over 9,000+ feet and has also been up Pikes Peak twice and MT Evans once now at 14,000 feet. Yes, the pipeline and Tioga Pass too. To Alaska on the Alaska Hwy and back on the Cassiar Hwy from Michigan.

Never had a head gasket issue either and the truck and the Duramax has been worked hard.

^ Well said ^

Just sold my 2005 fully loaded 2500 CC LLY Duramax with 102,000 miles for $23,500. Mint condition all service records including and oil analysis every 30,000 miles. There are cream puffs out there you just have to be patient and you will need to be willing to pay $20-25,000. I’m 6’4” and my kids out grew the crew cab so I had to move up to a mega cab. Never had an issue with and it towed our tt and lance camper it’s whole life. They do run hot so I put an auxiliary radiator on it and it cut the fan engagement in half. Like some have said find an LBZ if you can