Repair Services

Coolant Flange Aluminum – 06A 121 121C

The 06A 121 121C flange is an aluminum OE-style coolant flange for select Volkswagen and Audi vehicles. It restores leak-free cooling system performance with a direct bolt-on fit and no modifications required.

$29.00

  • Description
  • Additional information
  • Fits These Cars

Description

The 06A 121 121C flange is an OE-style aluminum replacement coolant flange for select Volkswagen and Audi vehicles equipped with the 1.8T four-cylinder engine. Mounted directly to the engine, this flange serves as a critical junction in the cooling circuit — directing coolant between the engine block, cylinder head, and connected hose assemblies to maintain proper coolant flow and stable operating temperature. This aluminum design offers improved resistance to heat-related degradation compared to the original plastic unit, making it a durable direct-fit upgrade for cooling system restoration.

 

Signs Your 06A 121 121C Flange Needs Replacing

A failing coolant flange will produce clear warning signs that should not be ignored. The most common indicators include visible coolant seepage or dripping around the flange mounting area, a persistent coolant odor from the engine bay after operation, and a low coolant warning light with no obvious external source. Physical inspection may reveal a cracked housing, corroded sealing surfaces, or a deteriorated gasket. Left unaddressed, a leaking flange leads to progressive coolant loss, unstable engine temperature, reduced heater output, and the risk of overheating.

 

Key Features of the 06A 121 121C Flange

  • OEM Reference: 06A 121 121C

  • Aluminum OE-style construction — more durable than the original plastic unit

  • Precision-formed for correct fit, angle, and mounting alignment

  • Designed to handle high temperatures and sustained cooling system pressure

  • Precision sealing surfaces to prevent coolant leaks

 

Service Notes

Always replace the O-ring or gasket at the mounting flange during installation — reusing the original seal is a common cause of post-repair leaks. Inspect all connected coolant hoses for swelling, softness, or cracking and replace if needed. Torque all fasteners to factory specification to avoid distorting the sealing surface. After installation, refill with the VW/Audi-approved coolant mixture and properly bleed the cooling system to remove trapped air before returning the vehicle to service.

 

Compatibility & Applications

Always verify fitment by VIN before ordering.

Make Model Generation Year Range Engine
Volkswagen Golf / GTI Mk4 1999–2006 1.8T / 2.0
Volkswagen Jetta Mk4 1999–2005 1.8T / 2.0
Audi TT / TT Quattro Mk1 (8N) 2000–2006 1.8T
Audi A4 B5 1997–2001 1.8T
Audi A4 B6 2002–2005 1.8T

Cross Reference Numbers

  • 06A 121 121

  • 06A 121 121A

  • 06A 121 121B

Additional information

Weight 0.75 lbs
Dimensions 8.0 × 5.0 × 4.0 in
Year Make Model Engine Notes
2000-2006 Audi TT 1.8T
1998-2000, 2004-2005 Volkswagen Beetle 1.8T
2006-2010 Volkswagen Beetle 2.0T
2006 Volkswagen GTI IV 2.0T
2000, 2006 Volkswagen Golf IV 1.8T
2000, 2006 Volkswagen Golf IV 2.0T
2004, 2006 Volkswagen Golf IV 1.9 TDI
1999, 2011 Volkswagen Jetta IV 2.0T
2000, 2005 Volkswagen Jetta IV 1.8T