Product Description
Cummins 3926381 — Genuine Intake Manifold Grid Heater & Plenum (Intake Manifold Cover) for 5.9L 12V
MPN: 3926381 | Also Known As: intake manifold cover, grid heater & plenum plate, intake heater assembly
Genuine Cummins one-piece grid heater and plenum assembly engineered for reliable cold starts on 5.9L 12-valve engines. This complete unit replaces worn or damaged heater/plenum assemblies and restores OEM cold-start performance. Direct-fit for 1989–1998 5.9L 12V Ram. Sold individually (1 per engine).
Features & Benefits
- Complete OEM assembly (heater element integrated into the plenum/cover) — not just a loose grid.
- Optimized cold-starts by preheating intake air to reduce white smoke and rough idle.
- One-piece plenum design used on 12-valve trucks for durable sealing and airflow.
- Direct-fit replacement using factory hardware and interfaces.
- Genuine Cummins quality for long service life and correct geometry.
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1993 | 5.9L 12V (6BT) | Ram 2500/3500 |
| 1994–1998 | 5.9L 12V (6BT) | Ram 2500/3500 |
Industrial/Off-Highway: Cummins B-series non-certified 5.9L applications — verify by ESN before ordering.
Compatibility Notes:
- Intended for 12-valve (1989–1998) one-piece heater & plenum setups. Not for 24-valve (1998.5–2002) VP44 or later common-rail systems.
- Gaskets/seals are sold separately; see “Often Paired With.”
Specifications
- Type: Intake manifold cover with integrated grid heater (one-piece plenum)
- OE Part Number: 3926381
- Quantity Required: 1 per engine (sold individually)
Often Paired With
- Intake heater grid gasket: Cummins 3969988 (reseals grid-to-mating surface)
- Intake horn gasket/hardware: year-appropriate horn gasket & bolts (varies by model)
What’s In The Box
- (1) Genuine Cummins Intake Manifold Grid Heater & Plenum Assembly (3926381)
- Gaskets/hardware sold separately (see “Often Paired With”).
Installation Tips
- Disconnect batteries before service; verify relay and power feed condition.
- Clean sealing surfaces; install a new grid gasket to prevent boost leaks.
- Torque fasteners to spec in a cross pattern; verify proper relay operation.
- After install, confirm heater cycles and check for intake leaks under boost.
FAQ
WILL THIS FIT MY 1989–1998 12-VALVE 5.9L RAM?
Yes—3926381 is the one-piece grid heater & plenum used on 12V 5.9L trucks (’89–’98). Confirm by VIN/ESN if needed.
IS THIS JUST THE HEATER GRID?
No—this is the complete OEM assembly (plenum/cover with integrated heater). If you only need the gasket, see Cummins 3969988.
WILL THIS FIT 1998.5–2002 24-VALVE OR 2003+ COMMON-RAIL?
No—those engines use different intake/heater configurations. This part targets the 12V one-piece setup.
HOW MANY DO I NEED?
One per engine.
IS THIS A GENUINE CUMMINS PART?
Yes—OE Cummins part 3926381 for accurate fitment and durability.
