Looking at buying an 04-06 2500HD diesel.. any tips?

[1320ms]

I'm looking to buy an 04-06 2500HD diesel, new to diesel's and GM, so wondering what to check specifically?

I've got my eye on an 06 w/95k miles on it, one owner dealer (http://www.gmtruckclub.com/forum/#) maintained (shows in carfax), but the bad news about it is that there was either a 5th wheel or gooseneck in it. I've been told on diesel ford's to avoid anything thats had one of those.. not sure if that rule still applies for GM, but I'd assume so seeing how it means it was most likely pulling something pretty heavy.

On top of that theres a loud droning noise coming from the passenger side front, which the dealer assured they'd fix, not sure what that could be.

One of the issues I have with it though is that since it had the 5th wheel in the bed, there are now 4 holes straight through the bed, and a trailer electrical hookup in the bed, I suppose thats more bargaining room with the dealer though. Both inside and out it looks really clean, carfax does show an accident on the front drivers side about a month before it was traded in, although I see absolutely no evidence of it (no tool marks on fender bolts, headlights have the same wear and markings, etc etc), so I assume whatever it was it didnt damage the truck. All in all it looks pretty good for being 4 years old.

Any input, or anything else to look for? Oh and is a K&N intake a bad sign?

What kind of maintenance do these things require? Never owned a diesel, and this truck will see less than 1000 miles a month on it if even that much. I'd stick with gas, but my racing has been picking up and my F150 just cant pull the large enclosed trailer I'm looking at.

The dealer does have the name of the previous owner and I'm waiting to hear back on if they can get permission from me to contact him.

Would an oil analysis be worth anything? Is that something I can get the dealer to do?

Are all 2500 diesel from 03+ come with an Allison trans? Is there a 6spd auto in any years? Any years better than others? Any reason the 06 motor is considered better?

A friend has an 07 classic (just a leftover 06) that has Allison trans badges on the doors, but the 06 I'm looking at does not have these.. any reason or difference?

Any other common issues to look for? I do recall when looking at the engine the piping on the turbo had a nice oil buildup on it up top

Thanks
Matt

[t613]

Yeah, don't pay attention to the new HD commercials with Patrick Warburton.

That's a really strange angle to try and sell trucks, "The lodge" commercial especially...

[Mark Rinker]

I'm looking to buy an 04-06 2500HD diesel, new to diesel's and GM, so wondering what to check specifically?

On top of that theres a loud droning noise coming from the passenger side front, which the dealer assured they'd fix, not sure what that could be.

Most likely a front wheel bearing. Should be fixed by dealer as part of 'reconditioning' for resale.Oh and is a K&N intake a bad sign?

Not necessarily a deal-breaker, but throw it in the trash and replace with an OEM peice. The 2006 LBZ housing and large round filters are the best thing going.What kind of maintenance do these things require?

Get the owner's manual and Duramax diesel supplement from the dealer, spend some time reading and researching.The dealer does have the name of the previous owner and I'm waiting to hear back on if they can get permission from me to contact him.

See what he did with the OEM intake and filter!!!Would an oil analysis be worth anything? Is that something I can get the dealer to do?

Sure, you can always ask.Are all 2500 diesel from 03+ come with an Allison trans?

Starting in 2001 to current, Allison 1000.Is there a 6spd auto in any years?

6speed came out in 2006Any years better than others? Any reason the 06 motor is considered better?

2006 is considered by many to be the peak - i.e. best combination of power, features, refinements, and before heavy EPA restrictions that rob mileage.A friend has an 07 classic (just a leftover 06) that has Allison trans badges on the doors, but the 06 I'm looking at does not have these.. any reason or difference?

Yes, they didn't glue any badges on. ;)Any other common issues to look for? I do recall when looking at the engine the piping on the turbo had a nice oil buildup on it up top

Oily buildup on intercooler piping is normal. Washes off in seconds, comes back in months...Thanks
Matt

You are welcome. Mark


Don't forget to have them provide you with the warranty/service history printout. Original injectors? Any major repairs?

[1320ms]

Thanks for the response Mark, any thoughts on the fifth wheel being on there?

I'm definitely considering this one and I think I can get the dealer to do an even trade on my 07 f150..

[Mark Rinker]

I wouldn't be afraid of the 5th wheel history. These trucks are made to tow. You can cover the holes with a slide in bedliner, or weld on patches from the bottom side and do a spray in bedliner.

[joed]

A friend has an 07 classic (just a leftover 06) that has Allison trans badges on the doors, but the 06 I'm looking at does not have these.. any reason or difference?

Matt

Does it have "Duramax Diesel" badges instead? The early 06s (built before 10/05, I think) were still considered the 'LLY' models, and had the older style door badges. This will also be evident by the eighth digit in the VIN - it will be a '2' for LLY, and a 'D' for the newer LBZ.

The only real difference is power ratings - 06 LLYs were still 310 hp while 06 LBZs were 360 hp. The 06 LLYs have all the other 'upgrades' of the LBZs.

I have an 06 LLY with 6-spd Allison - I love it.

Good luck in your search.

Joe.

[1320ms]

Thanks Joe - very good info - looks like this is in fact an early 06, as the 8th digit is a 2.

I've heard that the LLY's can have injector or overheating issues.. anyway to check this out beforehand?


Does it have "Duramax Diesel" badges instead? The early 06s (built before 10/05, I think) were still considered the 'LLY' models, and had the older style door badges. This will also be evident by the eighth digit in the VIN - it will be a '2' for LLY, and a 'D' for the newer LBZ.

The only real difference is power ratings - 06 LLYs were still 310 hp while 06 LBZs were 360 hp. The 06 LLYs have all the other 'upgrades' of the LBZs.

I have an 06 LLY with 6-spd Allison - I love it.

Good luck in your search.

Joe.

[joed]

From what I understand, all 06s (LLY & LBZ) got cooling system upgrades, such as larger radiator, fan, different air box/intake. I haven't heard as many complaints as with the older LLYs.

As far as injectors, not sure - I haven't heard of many issues, certainly not to the extent of the older LB7s (2001-2004). As far as checking them out, maybe the dealership would be willing to test them with the scanner?

Regardless, have them print out the service history. It will give a general idea of how trouble-free the truck has been.

At 95K miles, there is still a little factory warranty left on the engine (up to 100K), asssuming the truck hasn't already been in service for 5 yrs - it may have since it's an early 06. Mine is already out of warranty even with only 85K.

Hope this helps.

Joe.

[Mark Rinker]

Don't be concerned with the early 2006s. They are LBZs in every respect except the VIN digit and LLY designation.

All the good stuff / improvements learned from late 2004 and 2005 LLYs was in place by early 2006 models, as mentioned.

[Kennedy]

Like mentioned earlier, the 2006 LLY is identical to the LBZ with the exception of the 2006 H1A Hummer. Also don't count out the 2007 model year which had 2007 LBZ Classic models available and can still have warranty available.

[drcook]

If it is at a Chevy/GMC dealership of one kind or another, ask them to check and certify that there was not a tuner on the truck. The presence of a K&N filter is indicative of someone who could possibly have wanted to use one, as opposed to someone who believed in leaving the truck stock, the way it was.

The issues with tuners, is that if there was one used and there is any warranty still on the truck, GM can/would deny any warranty claims on the engine. There is a TSB out about detecting the use of a tuner.

If not a GM family dealership (ie: Ford/etc) see if they will let you take it to a GM dealership to be checked out.

A lot of trucks get traded in that were used by horse people and they usually have a ball in the bed. There are a lot of very low mileage tradeins like that here in Ohio.

dc

[Mark Rinker]

If it is at a Chevy/GMC dealership of one kind or another, ask them to check and certify that there was not a tuner on the truck. The presence of a K&N filter is indicative of someone who could possibly have wanted to use one, as opposed to someone who believed in leaving the truck stock, the way it was.

The issues with tuners, is that if there was one used and there is any warranty still on the truck, GM can/would deny any warranty claims on the engine. There is a TSB out about detecting the use of a tuner.

If not a GM family dealership (ie: Ford/etc) see if they will let you take it to a GM dealership to be checked out.

A lot of trucks get traded in that were used by horse people and they usually have a ball in the bed. There are a lot of very low mileage tradeins like that here in Ohio.

dc


Great points made here...