2019 International ProStar Cummins ISX15 — Should You Buy One?
Typical asking price: $52,000–$78,000. There are 2 high-severity known issues you need to know before handing over a check.
Kestrel Take
The International ProStar with Cummins power is a popular choice in fleets — the combination of International's cab and Cummins' proven engine is well-regarded. The ProStar itself has fewer fans than the LoneStar, but it's a capable long-haul truck at a lower price point.
Known Issues for the 2019 International ProStar Cummins ISX15
Ranked by wallet impact. These are documented, recurring problems — not freak accidents.
Same DEF/DPF/SCR concerns as all modern Cummins engines. ECM scan mandatory before purchase.
Repair cost range: $500-$4,500
EGR cooler failures and valve fouling are documented on ISX15s at higher mileage. Coolant loss signals cooler failure.
Repair cost range: $1,500-$4,000
ProStar cabs had documented ergonomic complaints and some electrical system issues. Diamond Logic faults are the main electrical concern.
Repair cost range: $200-$1,200
Walk-Away Red Flags
- ✗Active fault codes on ECM scan
- ✗Coolant loss or white smoke — EGR cooler
- ✗Multiple electrical system faults or warning lights
Good Signs
- ✓Cummins dealer engine service records
- ✓ECM scan clean
- ✓Cummins-powered ProStar preferred over A26-powered ProStar for long-term reliability
Found a specific International ProStar Cummins ISX15?
This page covers what goes wrong on the 2019 International ProStar Cummins ISX15 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.
Get My Verdict — $7.99No account required. Delivered to your inbox, usually within minutes.
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.