Thermostat for Cummins K19, K38, K50 diesel engines, aftermarket cooling system component that controls coolant circulation to maintain optimal engine operating temperature. Available in 150F and 180F opening temperature options. All part numbers are cross-referenced against OEM specs for direct matching.

Part numbers: 3076489, 3349225, 3629205, 135675, 146077, 3002964, 201737, 3022299
Fits: Cummins K19, K38, K50 diesel engine
Position: Engine cooling circuit, between cylinder head and radiator

What you are ordering
Price is per thermostat. All part numbers and temperature grades are separate variants, please select the correct PN and temperature rating from variant options. These thermostats are not interchangeable. Different part numbers have different opening temperature ratings (150F / 180F). Wrong selection will lead to slow warm-up, continuous overheating or poor fuel efficiency.

Specifications
Material: copper wax element + stainless steel valve assembly
Structure: wax-pellet temperature controlled thermostat
Opening temperature: 150F / 180F options, matched to OEM specification
Finish: pressure sealed, leakage and opening temperature tested before packing
Packing: individual protective bag, marked with part number and temperature

When to replace
Replace the thermostat when stuck open, stuck closed or slow response. Common failure signs: engine overheating, long warm-up time, low operating temperature. Replace the thermostat together with coolant during cooling system maintenance.

Fitting notes
Strictly confirm engine serial number and required opening temperature (150F or 180F) before ordering. Do not install thermostats of different temperature grades interchangeably. Follow Cummins service manual for cooling system bleeding after installation. If you are not sure which PN matches your engine, send us engine serial number for confirmation.

Warranty and shipping
Covered by a 12-month warranty against manufacturing defects. Orders are dispatched within 3–7 business days; DHL / FedEx delivery takes 5–10 business days. Tracking number is sent as soon as the parcel leaves our warehouse.

Note: manufacturer names and part numbers are used for identification and cross-referencing only. We are an independent aftermarket supplier and are not affiliated with, or authorised by, the original manufacturer. Please verify the part number against your engine's parts catalogue before ordering — our team is happy to help if you send us your engine model or serial number.