AutoMotor.ai
Used & Reman PACCAR MX-13
The 12.9L MX-13 in Kenworth T680 / Peterbilt 579 linehaul trucks. Emissions year and rating define the correct unit.
Hi 👋 I'm AutoMotor AI.
Looking for a PACCAR MX-13? I'll help narrow down the correct configuration and get you options.
What part do you need?
What truck is it for?
Specifications
- Displacement
- 12.9 L
- Configuration
- Inline-6 turbo diesel
- Horsepower
- 405–510 hp
- Torque
- 1,450–1,850 lb-ft
Common applications: Kenworth T680, Peterbilt 579 linehaul.
What to know before you buy
Compatibility
Heavy-duty fitment turns on more than year/make/model. Engine family, ECM calibration, emissions configuration (pre-EGR, EGR, DPF/SCR), and drivetrain ratios all matter. Our AI cross-checks the details you provide, and a specialist verifies fitment against the actual unit before anything ships.
Used vs. Rebuilt / Reman
Used (running take-out) units are the fastest and lowest-cost path when a low-hour core is available. Rebuilt/reman units cost more but ship with fresh internals and a longer warranty. For over-the-road trucks that need to stay earning, we'll lay out both so you can weigh downtime against total cost.
Warranty
Warranty terms vary by supplier and unit condition — used, rebuilt, and reman each carry different coverage. Options and exact terms are confirmed in your written quote before purchase; nothing is assumed.
Freight & Delivery
Heavy assemblies ship LTL freight on a pallet, typically 2–7 business days depending on lane and residential vs. commercial delivery. Liftgate and terminal pickup options are quoted per destination.
Frequently asked questions
Can I put a used truck engine in without matching the exact CPL/serial?
Often not. Emissions configuration, ECM calibration and rating have to line up. Give us the VIN or the engine serial and a specialist confirms the correct unit before you commit.
Used take-out vs. reman — which should I buy?
A low-hour used take-out is fastest and cheapest when one is available. Reman costs more but resets internals and warranty. We'll price both against your downtime.
How is a heavy engine shipped?
On a pallet via LTL freight, usually 2–7 business days. Liftgate and terminal pickup are quoted per destination.
Do you sell the whole engine or a long block?
Both are sourced depending on what your repair needs — complete running engines, long blocks, and short blocks. Tell the AI what failed and we'll target the right assembly.