Product Description

Cummins 5292742 — Genuine 180° Engine Coolant Thermostat for 5.9L ISB

MPN: 5292742  |  Also Known As: 180-degree thermostat, coolant thermostat  |  Related: 5292744 (190° OE-temp alternative), Mopar 5086739AB (190°)

Keep your 24-valve/CR 5.9L at the right temps. The genuine Cummins 5292742 180° thermostat drops in on 1998.5–2007 Ram 2500/3500 5.9L ISB and popular 3.9L 4BT builds. Ideal for owners who prefer a 180°F calibration for towing or warm climates. For stock ~190°F operation, see 5292744.

Features & Benefits

• OE build & calibration for consistent temperature control.
• Direct-fit for 5.9L ISB (1998.5–2007); no modifications required.
• Improved thermal stability under load with a 180°F set point.
• Durable wax element & seat for long, repeatable cycles.
• Backed by Cummins fit and quality.

Verified Fitment (Automotive)

Industrial/Off-Highway: Used primarily on B-Series 5.9L and 4BT 3.9L applications—verify by ESN for equipment/industrial engines.

Specifications

• Type: Engine coolant thermostat
• Nominal Temperature: 180 °F
• OE Part Number: 5292742
• Housing Seal (sold separately): 3954829
• Quantity Required: 1 per engine

Often Paired With

• Thermostat housing seal: Cummins 3954829 (recommended every service)
• 190° option: Cummins 5292744 (OE-temp) / Mopar 5086739AB
• Vertical water neck: Cummins 3943300 (as needed)
• Fresh coolant: refill/bleed after service

What’s In The Box

• (1) Genuine Cummins 180° Thermostat (5292742)
• Seal/gasket sold separately (see “Often Paired With”).

Installation Tips

• Drain coolant below thermostat level; clean all mating surfaces.
• Lightly lube and install a new 3954829 seal; orient thermostat correctly.
• Torque housing fasteners to spec; refill and bleed air.
• Verify temperature stabilization on warm-up and road test.

FAQ

WILL THIS FIT MY 1998.5–2007 5.9L CUMMINS RAM?

Yes—5292742 is a direct-fit 180° thermostat for 1998.5–2007 Ram 2500/3500 5.9L (VP44 & common-rail).

IS 180°F THE STOCK TEMPERATURE?

Many 2003–2007 trucks came with ~190°F thermostats. If you prefer OE temp, use 5292744 (190°) or Mopar 5086739AB.

WHAT SEAL DO I NEED?

Use the Cummins 3954829 thermostat housing seal anytime you replace the thermostat.

DOES THIS WORK ON 6.7L TRUCKS?

No—this listing targets 5.9L. 6.7L applications use different part numbers (e.g., 5292744 for certain years; verify by VIN/ESN).

IS THIS A GENUINE CUMMINS PART?

Yes—OE Cummins 5292742.