# International ProStar Used Price & Common Problems | Big Rig Risk

> International ProStar: used $16,950 to $70,904. Documented problems: possible ISX rebuild and oil pan leak. What to inspect before you buy.

**Verdict:** inspect

Used International ProStar: $16,950–$70,904 observed used across 15 listings. The documented cost risk to price in: a possible full ISX rebuild and an active oil pan leak. Buy only after inspection.

**Observed used price:** $16,950–$70,904

**Documented failure risks:**
- Possible ISX rebuild: An owner weighing a full ISX rebuild describes the motor as not yet showing major
- Oil pan leak: The same truck has an active oil pan leak ahead of the rebuild decision.
- Injectors run about $1,000 each; a relief valve was flagged : Injectors run about $1,000 each; a relief valve was flagged as a likely leak point
- VGT turbo fouling: Engine-family sources (shared platform, applies regardless of chassis brand): VGT turbo

## Sources
- [youtube.com](https://www.youtube.com/watch?v=kP3vMQJaAFI) (accessed 2026-08-19)
- [youtube.com](https://www.youtube.com/watch?v=CrDuDh0DsbM) (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)
- [dieselrebuildkits.com](https://dieselrebuildkits.com/) (accessed 2026-08-19)
- [How to CHECK FAULT CODEs on INTERNATIONAL PROSTAR](https://www.youtube.com/watch?v=hyTFaxqkDK0) (accessed 2026-08-19)
- [soarr.com dealer inventory listings (15 real listings observed 2026-09-05)](https://www.soarr.com/for-sale/trucks/0/International/ProStar/all-for-sale) (accessed 2026-09-05)
- [NHTSA recall 18V588000 (ENGINE AND ENGINE COOLING:ENGINE:DIESEL)](https://www.nhtsa.gov/recalls?nhtsacampaignnumber=18V588000) — "Navistar, Inc. (Navistar) is recalling certain 2017-2018 International ProStar and 9900i trucks, 2018-2019 International LT trucks, 2017-2019 International LoneStar and HX trucks and 2017 International PayStar trucks, equipped with Cummins ISX15 or X15 diesel engines.  In certain driving conditions, such as on a long down-hill grade, the fuel line may burst if the fuel pump cooling circuit screen becomes restricted." (accessed 2026-09-11)
- [NHTSA recall 08V618000 (SERVICE BRAKES, AIR:SUPPLY:HOSES, LINES/PIPING, AND FITTINGS)](https://www.nhtsa.gov/recalls?nhtsacampaignnumber=08V618000) — "NAVISTAR IS RECALLING 14,048 MY 2008-2010 LONESTAR AND PROSTAR TRUCKS.  THE SERVICE BRAKE AIR LINE THAT RUNS FROM THE TRACTOR PROTECTION VALVE TO THE FAST BRAKE MODULE MAY SEPARATE FROM THE FAST BRAKE MODULE RESULTING IN LOSS OF TRAILER SERVICE BRAKES." (accessed 2026-09-11)

_Last verified 2026-09-11. Source: Big Rig Risk — https://bigrigrisk.com/trucks/international-prostar-cummins-isx15/ — every claim checked against a primary source before publication (see /methodology/)._