PDI Big Boss Performance Dual Oil Cooler for Cummins X15 | ISX
Delivery and Shipping
Delivery and Shipping
Most orders ship within 24 business hours.
Description
Description
Available for: 1999-2026 Cummins X15 and ISX Engines
Key Benefits
- Dual high efficiency cooler packs
- 75% more oil cooling capacity
- Lowers peak oil temperature 20-30 degrees
- Thermostat and bypass valve included
- Complete new casting and assembly
- Made in the USA
Warranty: 1 Year Unlimited Mileage Warranty
Introducing the Big Boss Performance Dual Oil Cooler for Cummins X15 and ISX Engines, the ultimate solution for keeping your engine's oil cool and preventing the oil from breaking down prematurely.
Most drivers have noticed with newer engines that peak oil temperatures can reach 255 degrees and higher. We have addressed this issue with our new Dual Oil Cooler, which can keep your operating temps closer to the thermostat temperature.
Designed with a robust construction, the Performance Oil Cooler is built to withstand the toughest conditions and keep your engine running cool. With its innovative design, this oil cooler is guaranteed to deliver top performance, reliability, and durability.
| OEM Reference Part Number | 4386026, 4386025, 4386199, 4955831, 4965896, 4089583, 4965906, 4965895, 4955830, 3682787, 3682788, 4920199, 5394142, 4952498 |
RUNNING HOTTER THAN IT SHOULD?
Newer Cummins X15 and ISX engines can experience oil temperatures reaching 255°F and higher, especially under heavy loads and demanding operating conditions. Excessive oil heat can accelerate oil breakdown, increase thermal stress on internal components, and impact long-term engine reliability.
The PDI Big Boss Dual Oil Cooler was developed to address that problem with significantly greater cooling capacity and better oil-temperature control.
WHY PDI BUILT THE BIG BOSS DUAL OIL COOLER
PDI created the Big Boss Dual Oil Cooler to solve a growing problem in Cummins X15 and ISX engines: excessive oil temperatures.
As newer engines began running hotter, we saw the need for a better cooling solution that could help protect oil quality, reduce engine stress, and support long-term reliability.
After extensive development and testing, PDI engineered a complete dual-cooler system designed to deliver greater cooling capacity, better temperature control, and more confidence for the drivers and fleets who depend on their trucks every day.
This is the kind of story that separates it from a generic replacement cooler.
MORE THAN JUST LOWER TEMPERATURES
PROTECT YOUR OIL
Lower operating temperatures help slow premature oil breakdown and maintain proper lubrication.
REDUCE HEAT STRESS
Better thermal control helps reduce unnecessary heat-related stress on critical engine components.
PROTECT ENGINE LIFE
Improved oil-temperature control supports long-term engine durability and reliability.
PROTECT UPTIME
Keeping temperatures under control can help prevent heat-related problems from becoming costly downtime.
This is important because right now the customer sees technical specifications, but you want to translate those into “What does this do for me?”








