Buyer Research

2019 Kenworth T680 PACCAR MX-13 — Should You Buy One?

Typical asking price: $70,000–$100,000. There are 3 high-severity known issues you need to know before handing over a check.

Kestrel Take

The T680 is Kenworth's flagship aerodynamic Class 8 sleeper — aerodynamic, feature-loaded, and powered by PACCAR's own MX-13 engine. The MX-13 has grown into a reliable engine, but early versions (pre-2017) had well-documented problems. A 2019 is on the mature end of that platform — still verify with a diagnostic scan.

What we checked

No public record to reconcile against

We don't yet have a public record to check this one against. Federal complaint records thin out badly on older vehicles, so there is little to check against. What follows is our own write-up, and it has not been reconciled against an official record. Treat it as a starting point, not a verdict.

Known Issues for the 2019 Kenworth T680 PACCAR MX-13

Ranked by wallet impact. These are documented, recurring problems — not freak accidents.

PACCAR MX-13 EGR cooler failureHigh — wallet impact

EGR cooler failures on the MX-13 cause coolant loss and can lead to hydrolocking or catastrophic engine failure. This is the most expensive failure mode on this platform. White exhaust smoke is the warning.

Repair cost (estimate): $2,000-$5,000

Source: not yet checked against public records.

DEF system and NOx sensor failuresHigh — wallet impact

NOx sensors, DEF dosers, and SCR catalyst failures trigger derate modes. Pre-purchase ECM scan must show no active emissions faults.

Repair cost (estimate): $500-$3,000

Source: not yet checked against public records.

MX-13 fuel injector sealing washer wearHigh — wallet impact

Injector sealing washers leak externally, causing diesel smell and visible fuel weeping at the head. Common on higher-mileage MX-13s.

Repair cost (estimate): $1,000-$2,500

Source: not yet checked against public records.

ADAS camera and radar calibration (T680 with safety systems)Medium

The T680 with Bendix Fusion ADAS has radar and camera systems that require calibration after windshield replacement or front-end repairs. Verify all systems are active.

Repair cost (estimate): $500-$1,500 to calibrate

Source: not yet checked against public records.

Walk-Away Red Flags

  • White exhaust smoke — EGR cooler failure imminent or occurred
  • Active emissions fault codes on pre-purchase scan
  • Diesel smell at idle — injector sealing washer leak
  • Any ADAS warning lights active

Good Signs

  • Kenworth dealer PM history documented
  • ECM scan clean with no active faults
  • EGR cooler replaced or inspected recently
  • Long-haul highway use — easier on the platform than local or regional

Found a specific Kenworth T680 PACCAR MX-13?

This page covers what goes wrong on the 2019 Kenworth T680 PACCAR MX-13 in general. The Kestrel report covers this specific car— the asking price vs. market, the photos, the seller's description, and a BUY / NEGOTIATE / WALK AWAY verdict with a negotiation script.

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Known issues on this page are based on documented owner reports, NHTSA complaints, class-action records, and manufacturer technical service bulletins. Individual vehicles vary. A pre-purchase inspection by a trusted mechanic is always worth doing.

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