Product Description
Interstate-McBee M-3901020 Piston Cooling Nozzle – 89–93 5.9L Cummins 12V
Restore factory piston cooling and durability with this OEM-style piston cooling nozzle (oil squirter) for first-gen 1989–1993 Dodge Ram 2500/3500 trucks equipped with the 5.9L Cummins 12-valve (6BT). Interstate-McBee’s M-3901020 delivers precise oil jetting to the underside of the piston for better heat control under load.
- Direct replacement: Built to OEM form/fit/function for Cummins 3901020.
- Consistent oiling: Accurate jet targeting helps control piston temps and reduce thermal stress.
- Aftermarket value: OEM-style performance at a lower cost than genuine OEM.
- Pro-grade quality: Interstate-McBee diesel components are trusted across HD engine rebuilds.
Specifications
| Manufacturer | Interstate-McBee |
|---|---|
| Part Number | M-3901020 |
| OEM Reference | Cummins 3901020 |
| Application | 5.9L Cummins 12-valve (6BT) |
| Vehicle Years | 1989–1993 (Dodge Ram 2500/3500) |
| Position | Piston cooling nozzle (piston oil jet / oil squirter) |
| Material | Steel body |
What’s Included
- (1) Piston Cooling Nozzle (order 6 for a complete engine set)
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500, 5.9L Cummins 12-valve (6BT)
- Model Years: 1989–1993
Install Notes
- Inspect and clean the oil gallery and nozzle seat; verify each jet’s aim at the piston underside.
- Torque fasteners per the Cummins service manual and use new hardware where specified.
- Prime the lubrication system and verify oil pressure after installation.
- Tech tip: Some builders upgrade the oil pump when using nozzles with larger orifices to maintain oil pressure; confirm requirements for your build.
Warranty
Interstate-McBee new engine parts are typically covered for 24 months from date of installation under normal use (valvetrain exclusions may apply). Contact us for coverage details on this nozzle.
Cross-Reference & Related
- OEM Cross-Ref: Cummins 3901020 (single nozzle)
- Related (later years): Many 1994–2002 applications use Cummins 3937214 nozzles (check ESN).
Why Buy From CPP Diesel
- ESN-verified fitment help from real diesel techs
- Fast shipping and easy returns
- Huge selection of 1st-Gen Cummins maintenance and rebuild parts
FAQ
Is M-3901020 correct for all 5.9L Cummins engines?This nozzle targets 1989–1993 5.9L 12-valve truck applications. Later models (1994–2002) often use a different nozzle (e.g., 3937214). Verify by ESN.
How many nozzles does a 5.9L use?
Six—one per cylinder. Order a quantity of 6 for a complete engine set.
Do I need to upgrade the oil pump?
Not always. Some larger-orifice designs may reduce oil pressure; many builders upgrade the pump in those cases. Check your build specs and monitor oil pressure on first start.
What symptoms point to a bad piston cooling nozzle?
Elevated piston temps, scuffing, or localized detonation damage; low oil pressure can also be a factor. Inspect during rebuilds or when repairing bottom-end issues.
Is this an OEM Cummins part?
This listing is for an Interstate-McBee aftermarket nozzle built to OEM-style specs. For genuine OEM, see Cummins 3901020.
