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)

Industrial/Off-Highway: Cummins B-series non-certified 5.9L applications — verify by ESN before ordering.

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.