Four Seasons 90041 HVAC Heater Core

Four Seasons 90041 Heater Core for Lexus RX300

The Four Seasons 90041 heater core is an aluminum HVAC replacement built for 1999-2003 Lexus RX300 models. It is specified as an OE-matching heater core replacement and uses aluminum core construction for efficient heat transfer in the vehicle’s heating system.

Key Features

• Brand: Four Seasons Heater Core
• Part number: 90041
• Fits 1999-2003 Lexus RX300, heater core application
• Aluminum heater core construction
• Core dimensions: 10-1/2 in. height, 4 in. width, 1-1/4 in. depth
• Tube size: 0.750 in. / 19.050 mm on both connections
• Meets or exceeds OEM requirements
• Direct HVAC core replacement for the Lexus RX300 heating system

Detailed Description

Four Seasons 90041 is an aluminum heater core designed for the HVAC system in the 1999-2003 Lexus RX300. With a core height of 10.500 inches, width of 4.000 inches, and depth of 1.250 inches, this heater core is built to match the original application dimensions closely. The aluminum core material supports heat exchange within the cabin heating circuit, while the 0.750-inch inlet and outlet tube sizing helps maintain proper coolant flow through the heater assembly. If you are replacing a leaking or restricted heater core in a Lexus RX300, part number 90041 provides a direct-fit service part for the listed model years.

This part cross-references APDI 9010374 for the same application.

Common Issues This Part May Resolve

• Loss of cabin heat in a 1999-2003 Lexus RX300
• Coolant odor or moisture inside the HVAC case area
• Restricted coolant flow through the heater circuit
• Heater core leakage affecting defrost and cabin comfort
• Temperature inconsistency from the vehicle’s heating system

Installation Notes and Tips

Verify the heater core dimensions and tube orientation against the removed unit before installation. Because this component is located within the HVAC system, access typically requires disassembly of surrounding interior trim and heater case components. Inspect hoses, clamps, and coolant condition during replacement, and confirm the cooling system is properly filled and bled after installation. Use the vehicle’s service information for the correct procedure on the Lexus RX300.

Quality Assurance

Four Seasons lists this heater core as meeting or exceeding OEM requirements. The 90041 is part of the Four Seasons Heater Core line, which focuses on replacement HVAC core components for vehicle heating systems.