Product Description
Genuine Cummins
Cummins 3969988 — Intake Heater Grid Gasket (5.9L B-Series)
MPN: 3969988 | Also Known As: intake grid gasket, connection gasket | Material: Graphite/Composite (OE style)
Why This Part
- ✓ OE-spec seal between the intake horn and grid heater to prevent boost leaks.
- ✓ Direct-fit for 5.9L Cummins B-Series across 1989–2007 (12V, 24V, CR).
- ✓ Sold individually—two are typically required (top & bottom of grid heater).
- ✓ Replaces worn or crushed gaskets whenever the intake is serviced.
OE Fit Boost-Leak Prevention 2 Per Service
Quick Specs
| Type | Intake heater grid / intake horn connection gasket |
|---|---|
| OE Part # | 3969988 |
| Qty Needed | Usually 2 per engine service (sold individually) |
| Placement | Between intake horn and grid heater; also used top/bottom of grid heater |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–2007 | Cummins 5.9L B-Series (12V / 24V / Common-Rail) | Ram 2500/3500 |
Notes: OE Cummins connection/heater grid gasket for 5.9L; typically two required per service (top & bottom). Verify by VIN/ESN if components have been changed.
Often Paired With
- Heater Grid: Cummins 3969987 (’98.5–’07 24V/CR)
- Intake horn bolts/hardware (replace if corroded or stretched)
- MAP/boost leak check after reassembly
What’s In The Box
- (1) Genuine Cummins Intake Heater Grid / Connection Gasket (3969988)
- Sold individually—order 2 if servicing the grid heater.
Install Tips
- Clean both mating surfaces thoroughly; no debris or old gasket material.
- Follow a criss-cross torque pattern on the intake horn fasteners.
- Pressure/boost-test after install to confirm a proper seal.
FAQ
WILL THIS FIT MY 1989–2007 5.9L CUMMINS?Yes—this OE gasket is used across 12-valve, 24-valve, and 2003–2007 common-rail 5.9L applications.
HOW MANY GASKETS DO I NEED FOR A GRID HEATER SERVICE?Two—one above and one below the grid heater. This part is sold individually.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3969988 with the correct material and cutout profile.
CAN I REUSE THE OLD GASKET?Re-use isn’t recommended. Replace any time the intake horn or grid heater is removed to prevent boost leaks.
WHAT’S THE MATCHING HEATER GRID PART NUMBER?Cummins 3969987 is commonly paired with this gasket on 24V/CR trucks.
