I need some help with an LLY question

[socaltoolguy]

When were the head gaskets replaced? Did they use bolts or studs to clamp things back together?
Has the transmission fluid been regularly drained and refilled with a fresh screw on filter can?
Did the engine coolant get changed at 150K?
Is the truck bed whole or has there been a 5th wheel mount bolted on? (speaks to the engine's working life)
Has the seller been religiously using a fuel additive on every tank of fuel? ULSD diesel is not very slippery...

I have well over 230K miles on mine and replaced the gaskets at about 160K. Used ARP studs. Pulls like a freight train.

Can you give me some info on the fuel additive? I had a 2001 Duramax that we full timed with and never put anything in the tank except diesel. Did I do a bad thing? I'm just asking because I want to do right with my next truck. Also, what year trucks had to have an additional tank for the needed additive? Was it 08-09???

[rapidoxidationman]

I'm not sure what year DPF became a necessary fluid for the truck to run - 2012 maybe? Someone here will tell you with more certainty.

Regarding fuel additive, I've always used Power Service in the gray bottle. Some would say it's the bottom of the barrel for fuel additives, but I've yet to have a fuel related issue with my diesel engines and I've had 6 between cars and trucks. FPPF is seemingly a preferred brand, but isn't as easy to get here. Additive will keep the fuel system slippery and clean, something today's low lubricity fuel might not do as well as it should.

[DmaxMaverick]

DPF = Diesel Particulate Filter -- 2007.5
DEF = Diesel Emissions (Exhaust, etc.) Fluid -- 2012

[rapidoxidationman]

^this

[Kennedy]

2011 models have DEF

[More Power]

Of all of the Duramax 6600 engines, the LLY is mentioned occasionally as the one that runs too warm, due perhaps to changes in the cooling system and intercooler for that generation engine. Most owners don't have a cooling problem, but those who tow heavy in the high heat of a southwest summer might.

There are solutions to this overtemp issue with the LLY. The best I've heard involved retrofitting 2006 factory LBZ cooling system parts.

[socaltoolguy]

Thanks to all of you who took the time to reply. So, from what I'm gathering, I don't really have much to worry about with an LLY motor. That's great. Now all I have to do is find a truck that I can afford. One more question, At what point should miles become a factor? I realize that maintenance plays a huge roll but I am seeing a lot of trucks for sale with 175k to 200k miles. When I sold our truck it only had 70k on it. I was told that it wasn't even broken in yet. So, at what point should I say, "too many miles"?


Ray