Used GMC Sierra 2500HD 6.6 Duramax Engine
Used OEM 6.6L Duramax V8 diesel engines for the GMC Sierra 2500HD. The Duramax has changed several times since 2001 (LB7, LLY, LBZ, LMM, LML and L5P), and each version has its own fuel system, emissions hardware and wiring, so we match the engine to your VIN, confirm the mileage in writing before you pay, and ship it free by liftgate freight with a 3-year parts warranty.
Mon – Sat, 7 AM – 7 PM (Arizona Time)
Representative PhotoVIN Matched
Exact part number
Written Quote
Before you pay
Free Liftgate Freight
7–14 business days
3-Year Parts Warranty
Major internal parts
Common vehicles we source for
Duramax engines for these Sierra 2500HD years. Other years and the Sierra 3500HD on request.
Fitment, price, and mileage are confirmed against your VIN and sent to you in writing before you pay. Photos are representative.
Get your exact price
Call, text or fill in the form — whichever is easier. A parts specialist matches the part to your VIN and sends the price, mileage, warranty and delivery window in writing before you pay.
Mon – Sat, 7 AM – 7 PM (Arizona Time)
Get a free quote
Takes 30 seconds. Price confirmed in writing before you pay.
How ordering works
Call or text your VIN
A parts specialist matches the exact part number for your vehicle through our partner yard network.
Get a written quote
Part, mileage, price, warranty, and delivery window in writing before you pay.
Free freight delivery
Shipped to your shop or home with liftgate service, typically in 7–14 business days.
Frequently asked questions
The engine code depends on the model year and is shown by the 8th character of your VIN. Send us the full VIN and we will match the exact Duramax version your truck was built with.
It is not a simple swap. Each Duramax version uses different injectors, fuel system parts, sensors, wiring and emissions equipment, so we recommend replacing your engine with the same version your Sierra came with.
Ask your mechanic to flush or replace the fuel system parts if the old engine failed from contaminated fuel, check the turbocharger, intercooler piping and cooling system, and start with fresh oil, filters and coolant. Fix whatever caused the original engine to fail before installing the replacement.
Yes. Every used engine comes with our 3-year parts warranty on major internal components when installed by an ASE certified mechanic. Full terms are on our Terms & Warranty page and on your written quote.
Not sure which part you need?
Send us your VIN and we'll confirm the exact part number, price, and delivery window.