Nissens 73921 HVAC Heater Core

Nissens 73921 HVAC Heater Core

The Nissens 73921 HVAC heater core is built for Volkswagen and Audi applications that need reliable cabin heat and stable thermal performance. It uses an aluminum core with plastic tanks and mechanically jointed cooling fins for a durable OE-style construction.

Compatible with select Volkswagen Beetle, Golf, Jetta, and R32 models, as well as Audi TT and TT Quattro applications, this heater core is a direct-fit replacement for vehicles across the 1988-2010 model years. Nissens 73921 is engineered to match the original heater core layout for proper HVAC system operation.

Key Features

• Aluminum core material for efficient heat transfer
• Plastic tank construction for OE-style fit and function
• Mechanically jointed cooling fins for consistent core assembly
• Pipe not included
• Fits a wide range of Volkswagen and Audi HVAC applications
• Part number 73921 for easy identification

Detailed Description

Nissens develops thermal management components with a focus on OE-level fit and material selection. The 73921 heater core uses an aluminum core paired with plastic tanks, a common factory-style design for HVAC systems that need dependable heat exchange inside the cabin. Its compact dimensions help it fit the specified Volkswagen and Audi heater core housings without unnecessary modification.

This part cross-references Anchor 9903 and 9936 for the same application. It also cross-references OE and aftermarket numbers including 1J1819031, 1J1819031A, and 1J1819031B. Use part number 73921 when verifying the correct heater core for your vehicle.

What It Helps Address

• Weak or inconsistent cabin heat
• Coolant leakage from a damaged heater core
• Restricted heat transfer inside the HVAC system
• Fogging caused by poor defrost performance
• Replacement needs after corrosion or internal blockage

Installation Notes and Tips

Confirm vehicle fitment by year, model, and chassis/VIN notes before ordering. Fits 1999-2010 Volkswagen Beetle, N/A; 2000-2006 Audi TT, N/A; 2000-2006 Audi TT Quattro, N/A; 1999-2006 Volkswagen Golf, N/A; 1988-1989 Volkswagen Golf, N/A; 2005 Volkswagen Jetta, Wagon; 2005 Volkswagen Jetta, Sedan (To Chassis/VIN 9M-5-149 999); 2005 Volkswagen Jetta, To Chassis/VIN 9M-5-149 999; 1997-2004 Volkswagen Jetta, N/A; 2004 Volkswagen R32, N/A; 1999 Volkswagen Golf, From Chassis/VIN 1J-X-250 001. Verify the heater core housing condition, flush the cooling system if contamination is present, and inspect seals and HVAC components during replacement.

Quality Assurance

Nissens is a market-leading manufacturer of thermal and engine efficiency components, and its products are developed and manufactured to a consistent quality standard. Part number 73921 reflects that OE-style approach for Volkswagen and Audi heater core replacement.