Product Description
Interstate-McBee M-3959031 Oil Cooler – 03–07 5.9L Cummins
Restore stable oil temperatures and protect your ISB with this direct-fit oil cooler engineered to OEM dimensions for 2003–2007 Dodge Ram 2500/3500 5.9L Cummins (24-valve common rail). Built for durability and heat transfer efficiency in demanding diesel duty cycles.
- OEM-style fit & function: Matches Cummins 3959031 specifications for a seamless install.
- Heat-resistant construction: Robust core for consistent oil temp control and bearing protection.
- Aftermarket value: Interstate-McBee quality at a lower cost than OEM.
- Truck-ready: Designed for 03–07 Dodge Ram 5.9L Cummins applications (see Fitment).
Specifications
| Interstate-McBee Part | M-3959031 |
|---|---|
| OEM Reference | 3959031 (Cummins) |
| Additional References | 4896407, 3902434, 3903375 (verify by ESN/build date) |
| Application | B/ISB/QSB Family (see truck fitment below; industrial varies by ESN) |
| Position | Engine Oil Cooler (core) |
| Included | (1) Oil cooler core |
Vehicle Fitment
Always verify by engine serial number (ESN) or VIN/build date when possible.
- Dodge Ram 2500/3500 – 5.9L Cummins ISB (24-valve common rail)
- Model Years: 2003–2007 (some catalogs denote 2003.5–2007; check ESN for early-2003 builds)
- Note: Also found on select B/ISB/QSB applications (e.g., QSB 4.5) depending on configuration; confirm by ESN.
Recommended Related Parts
- Oil Cooler to Block Gasket – Interstate-McBee M-4895742 (sold separately)
- Cooler to Filter Head Gasket – Interstate-McBee M-3864458 (sold separately)
- Fresh oil & filter after cooler replacement
Installation Notes
- Drain coolant and oil per service manual; cap lines to prevent contamination.
- Clean mating surfaces; replace gaskets and torque fasteners to factory specs.
- After installation, change oil/filter and verify no leaks; re-check levels after warm-up.
Warranty
Interstate-McBee new engine components include manufacturer warranty coverage. Terms vary by category; contact us for details specific to this oil cooler.
Why Buy From CPP Diesel
- Expert Cummins fitment support, ESN verification, and fast shipping
- Curated B/ISB parts for full service jobs—gaskets, filters, and fluids
- Hassle-free returns and real tech help
FAQ
Will this fit my 2003 Dodge Ram 5.9L?Yes—this cooler is listed for 2003–2007 5.9L Cummins ISB trucks. Early 2003 builds may be noted as 2003.5 in some catalogs—verify by ESN to be sure.
Does the kit include gaskets?
The cooler is sold as the core only. We recommend adding the oil cooler to block gasket (M-4895742) and cooler to filter gasket (M-3864458).
How does this compare to a genuine Cummins cooler?
Interstate-McBee builds to OEM-equivalent dimensions and function, offering a reliable and cost-effective alternative to the Cummins 3959031 OE unit.
Do I need to change the oil after replacement?
Yes—replace engine oil and filter after installation to remove any residual debris and ensure proper lubrication.
Product Videos
Custom Field
YEAR 2003-2007
MAKE DODGE
ENGINE L
