Nissens 77634 HVAC Heater Core

Nissens 77634 Heater Core for Hyundai and Kia

Nissens 77634 is an aluminum HVAC heater core built for direct replacement in select Hyundai and Kia applications. It is engineered with brazed cooling fins and aluminum tanks to support efficient heat transfer and consistent cabin heat output.

Key Features

• Aluminum core material for thermal efficiency
• Aluminum tank material for a lightweight, corrosion-resistant design
• Brazed cooling fins for durable heat exchange construction
• Pipe included for application-specific installation
• Fits 1999-2005 Hyundai Sonata, N/A
• Fits 2001 Hyundai XG300, N/A
• Fits 2002-2005 Hyundai XG350, N/A
• Fits 2001-2006 Kia Optima, N/A

Detailed Description

This Nissens heater core, part number 77634, is a thermal management component for the HVAC system in select Hyundai Sonata, Hyundai XG300, Hyundai XG350, and Kia Optima models. The aluminum core and aluminum tank construction help support heat transfer inside the heater box, while the brazed fin design provides a compact, service-ready structure. Nissens develops and manufactures thermal components with a focus on consistent quality and ongoing aftermarket coverage as vehicle technology changes.

This part cross-references Spectra Premium 99221 for the same application.

What It Helps Address

• Weak or uneven cabin heat
• Coolant seepage from a leaking heater core
• Restricted heat flow through a clogged core
• Fogging or moisture issues tied to heater core failure
• HVAC performance loss in Hyundai Sonata and Kia Optima applications

Installation Notes and Tips

Verify vehicle fitment by year and model before installation. Heater core replacement typically requires access to the HVAC case, so inspect coolant condition, hoses, and seals during service. Flush the cooling system if contamination or debris is present, and confirm all connections are secure after installation.

Quality Assurance

Nissens manufactures thermal management components to controlled quality standards for aftermarket service. Part number 77634 is built as an OE-style replacement heater core for the listed Hyundai and Kia vehicles.