# Peterbilt 579 Used Price & Common Problems | Big Rig Risk

> Peterbilt 579: one used listing at $9,000. Documented problems: fuel pump and spun main bearings. What to inspect before you buy.

**Verdict:** inspect

One observed listing at $9,000, a thin comp set. Biggest documented cost risk: the fuel pump, the most common complaint. Buy only after inspection.

**Observed used price:** $9,000–$9,000

**Documented failure risks:**
- Fuel pump: Fuel pump is the headline complaint: "the most common problem is the fuel pump... from 17
- EGR valve sticking open: EGR valve sticking open from carbon buildup at low idle causes derate/check-engine; advice
- Spun main bearings: Francisco Amaya's mechanic-perspective video documents spun main bearings from deferred
- In-frame rebuild findings: A full documented in-frame rebuild on an X15 found the intake valves needed reseating along with new valve springs and cam bearings, an add-on cost of about $4,600 in parts and labor.
- VGT turbo fouling: Engine-family sources (shared Cummins 15L platform): VGT turbo carbon/soot fouling called

## Sources
- [youtube.com](https://www.youtube.com/watch?v=oh6-x3lp-iM) (accessed 2026-08-19)
- [youtube.com](https://www.youtube.com/watch?v=vp3cl3E7Etw) (accessed 2026-08-19)
- [youtube.com](https://www.youtube.com/watch?v=Yvkt5L-AO9E) (accessed 2026-08-19)
- [dieselpro.com](https://dieselpro.com/blog/cummins-isx-history-specs-common-issues/) (accessed 2026-08-19)
- [4btengines.com](https://4btengines.com/top-isx15-problems/) (accessed 2026-08-19)
- [cylinder-heads.com](https://www.cylinder-heads.com/cummins-isx/) (accessed 2026-08-19)
- [youtube.com](https://www.youtube.com/watch?v=CrDuDh0DsbM) (accessed 2026-08-19)
- [youtube.com](https://www.youtube.com/watch?v=Vz2OVWLaFes) (accessed 2026-08-19)
- [dieselrebuildkits.com](https://dieselrebuildkits.com/) (accessed 2026-08-19)
- [truckpaper.com](https://www.truckpaper.com/listings/for-sale/peterbilt/579/conventional-day-cab-trucks) (accessed 2026-08-19)
- [NHTSA recall 20V199000 (ELECTRONIC STABILITY CONTROL (ESC))](https://www.nhtsa.gov/recalls?nhtsacampaignnumber=20V199000) — "PACCAR Incorporated  (PACCAR) is recalling certain 2008-2019 Peterbilt 330, 335, 337, 340, 348, 365, 367, 384, 386, 387, 388, 389, 567, 579 and 587 vehicles and 2008-2020 Kenworth T170, T270, T370, T660, T680, T800, T880, and W900 vehicles equipped with NAMUX Software.  In the event that the Anti-lock Brake System (ABS) loses battery and/or ignition power to the controller, the dash warning light for the ABS may not illuminate to warn the driver of the loss of ABS.  As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 121, "Air..." (accessed 2026-09-11)
- [NHTSA recall 25V181000 (ELECTRICAL SYSTEM:PROPULSION SYSTEM)](https://www.nhtsa.gov/recalls?nhtsacampaignnumber=25V181000) — "PACCAR Incorporated (PACCAR) is recalling certain 2022-2025 Peterbilt 520, 579, and 2021-2025 Kenworth T680 trucks.  The high voltage (HV) contactors may open, causing a sudden loss of high voltage and a loss of drive power." (accessed 2026-09-11)

_Last verified 2026-09-11. Source: Big Rig Risk — https://bigrigrisk.com/trucks/peterbilt-579-cummins-x15/ — every claim checked against a primary source before publication (see /methodology/)._