Product Description
Interstate-McBee M-3975818 Engine Oil Cooler – 2007.5–2024 6.7L Cummins (Select 2003–2007 5.9L)
Heavy-duty, OEM-spec engine oil cooler designed to restore proper oil temperature control and pressure stability. The M-3975818 is a direct-fit aftermarket replacement for ISB/QSB applications and is widely used on 2007.5–2024 6.7L Cummins (Dodge Ram 2500/3500), with select fitment on 2003–2007 5.9L B-series/ISB when superseded by ESN. Always verify by engine serial number (ESN).
- Direct-fit replacement: Built to OEM dimensions for easy install and factory performance.
- Meets OEM specs: Quality materials and precise core construction for reliable cooling.
- Fixes common failures: Addresses restriction or internal leakage that elevates oil temps.
- Best practice: Replace related cooler-to-filter head and cooler-to-block gaskets during service.
Specifications
| Manufacturer | Interstate-McBee |
|---|---|
| Part Number | M-3975818 |
| OEM Cross-Refs | Cummins 3975818 (primary), 3975817; legacy supersessions: 3902372, 3902434, 3903375 |
| Application Family | Cummins ISB / QSB (B-Series) |
| Includes | Oil cooler core/assembly (gaskets sold separately) |
| Recommended Gaskets | M-3974127 (cooler→filter head), M-2830559 (cooler→engine block) |
Vehicle Fitment
Confirm by ESN for exact applicability, especially on model-year splits and rebuilt engines.
- Dodge Ram 2500/3500 6.7L Cummins: 2007.5–2024 (ISB 6.7L)
- Dodge Ram 2500/3500 5.9L Cummins: 2003–2007 (select B-series/ISB applications where cooler supersedes)
- Notes: 2007 is a split year—early 2007 is 5.9L; mid-year (2007.5+) is 6.7L.
Installation Tips
- Drain oil and coolant as required; cap lines to prevent contamination.
- Replace both sealing gaskets (cooler→block and cooler→filter head).
- After any bearing/turbo failure, thoroughly flush the oil system and replace the filter.
- Prime the cooler with clean oil; follow Cummins service manual for torque specs and sequences.
Warranty
Interstate-McBee new engine parts carry manufacturer warranty coverage. Contact us with your ESN for assistance and exact terms.
Cross-Reference
Cummins 3975818 (primary), 3975817. Common legacy numbers: 3902372, 3902434, 3903375.
Recommended Add-Ons
- Interstate-McBee M-3974127 – Oil Cooler Gasket (to Filter Head)
- Interstate-McBee M-2830559 – Oil Cooler Gasket (to Engine Block)
- Fresh oil/filter; cooling system conditioner as required
FAQ
Will this fit my 2010 Ram 6.7L?Yes. The M-3975818 is widely used across 2007.5–2024 6.7L ISB applications. Verify by ESN to be certain.
Does it work on a 2006 Ram 5.9L?
In many cases, yes—certain 5.9L ISB/B-series engines (2003–2007) use this cooler by supersession. Confirm by ESN before ordering.
Which gaskets do I need?
Use two new seals: M-3974127 (cooler→filter head) and M-2830559 (cooler→block). Replacing both is best practice to prevent leaks.
Do I need to flush the system after a cooler or turbo failure?
Yes. Flush the oiling system, replace the filter, and prime the replacement cooler to prevent debris-related damage.
Where can I find torque specs?
Refer to the Cummins service manual for model-specific torque values and procedures.
Product Videos
Custom Field
YEAR 2003-2022
MAKE DODGE
ENGINE 5.9L,6.7L
