Cummins 5292738 — Genuine 180° Engine Coolant Thermostat for 5.9L 12-Valve

MPN: 5292738  |  Also Known As: thermostat, engine coolant thermostat  |  Gasket (sold separately): 3923331

Restore proper warm-up and operating temperature on your first-gen 5.9L. This genuine Cummins 180° thermostat is the OE drop-in for 1989–1993 Ram 2500/3500 5.9L 12-valve (VE-pump). Built to OEM specs for consistent regulation and long service life.

Features & Benefits

• OE temperature control to protect pistons, bearings, and turbo from thermal stress.
• Direct-fit drop-in for first-gen 5.9L 12-valve (no modification required).
• Jiggle-pin vent helps purge air for stable coolant temps.
• Durable thermostat element for repeatable open/close cycles.
• Backed by Cummins quality and fitment.

Verified Fitment (Automotive)

Industrial/Off-Highway: Used primarily on B-Series era 5.9L engines (BS3). For non-automotive 4BT/6BT usage, verify by ESN prior to ordering.

Specifications

• Type: Engine coolant thermostat
• Nominal Temperature: 180 °F (opens ~181.4 °F; fully open ~203 °F)
• Venting: Jiggle-pin
• Housing Bore Diameter (req.): ~54.25 mm
• OE Part Number: 5292738
• Gasket (sold separately): 3923331
• Quantity Required: 1 per engine

Often Paired With

• Thermostat housing gasket: Cummins 3923331 (recommended with each thermostat change)
• Fresh coolant: refill/bleed according to service manual
• Upper/lower radiator hoses & clamps: inspect/replace if aged

What’s In The Box

• (1) Genuine Cummins 180° Thermostat (5292738)
• Gasket sold separately (see “Often Paired With”).

Installation Tips

• Drain coolant below thermostat level; remove housing and clean mating surfaces.
• Install thermostat with jiggle-pin oriented upward; use a new 3923331 gasket.
• Torque housing fasteners to spec; refill with correct coolant mix and bleed air.
• Verify opening behavior by monitoring coolant temp after warm-up.

FAQ

WILL THIS FIT MY 1989–1993 5.9L CUMMINS?

Yes—5292738 is the OE 180° thermostat for first-gen 5.9L 12-valve Ram 2500/3500.

WHAT GASKET DO I NEED?

Use Cummins 3923331 thermostat housing gasket each time you replace the thermostat.

WHAT ARE THE OPENING SPECS?

Nominal 180 °F; begins opening around ~181.4 °F and is fully open near ~203 °F (jiggle-pin vented).

DOES THIS FIT 1994+ OR 6.7L TRUCKS?

No—later 5.9L/6.7L applications use different thermostats. Check by VIN/ESN for the correct part.

IS THIS A GENUINE CUMMINS PART?

Yes—OE Cummins 5292738.