Four Seasons 85421 Engine Coolant Water Inlet

Engine Coolant Water Inlet for Nissan and Infiniti

Four Seasons 85421 is an engine coolant water inlet built for direct replacement on select Nissan and INFINITI applications. It is a thermoplastic inlet with a 1.375 in. inlet diameter, a 2.283 in. maximum height, and a 2.093 in. bolt hole center-to-center measurement for fitment-focused service work.

Compatible With 2002-2017 Nissan and INFINITI cooling system applications, this Four Seasons Water Inlet line part is made to meet or exceed OEM requirements and is supplied without a thermostat or gasket/seal.

Key Features

• Four Seasons Water Inlet line part number 85421
• Engine coolant inlet, style: without thermostat
• Thermoplastic construction for cooling system service
• 1.375 in. inlet diameter
• 2.093 in. bolt hole center-to-center spacing
• 0.425 in. mounting flange width
• Meets or exceeds OEM requirements
• Gasket or seal not included
• Thermostat not included

Detailed Description

Four Seasons 85421 is an engine coolant water inlet used in thermostat and housing service on select Nissan Armada, Nissan TITAN, Nissan Pathfinder, Nissan NV2500, Nissan NV3500, INFINITI QX56, INFINITI FX45, INFINITI M45, INFINITI Q45, and Pathfinder Armada applications. The thermoplastic body is designed as an inlet-only component, making it a direct-fit replacement for cooling system repairs where the original inlet has cracked, warped, or begun leaking. This part cross-references Motorad CH6900 for the same application.

Four Seasons 85421 is a practical replacement choice when servicing the coolant inlet on Nissan and INFINITI V8 cooling systems. The part number 85421 is commonly searched for water inlet replacement on Nissan TITAN and Nissan Armada cooling repairs, as well as INFINITI QX56 and FX45 thermostat housing service.

Common Repair Uses

• Coolant seepage at the water inlet housing
• Cracked or heat-damaged thermoplastic inlet
• Corrosion or wear at the mounting surface
• Replacement during thermostat housing service
• Restoration of proper coolant routing in the engine cooling system

Installation Notes and Tips

Verify the inlet diameter, bolt hole spacing, and mounting flange width against the original part before installation. This inlet is supplied without a thermostat and without a gasket or seal, so those components must be matched separately as needed for the repair. Clean the mating surfaces thoroughly and inspect the surrounding cooling system components for wear, residue, or cracking before reassembly.

Quality Assurance

Four Seasons identifies this water inlet as meeting or exceeding OEM requirements for the listed applications. The Water Inlet product line is built for cooling system replacement work where accurate fit and material consistency matter.