Radiator Overflow Bottle – Audi A6/A7 C7, A8 D4 (4G0121403AG)

This high-quality TEILEX radiator overflow bottle (DM1409) is a direct replacement for Genuine Part Number Reference: 4G0121403AG, also referenced as 4G0121403AC, 4G0121403D, and 4G0121403G. It acts as the coolant expansion tank for the engine cooling system, accommodating coolant expansion as it heats up and helping maintain correct system pressure. Also known as a coolant expansion tank or coolant reservoir bottle. Fits across all engine variants of the listed chassis, as the bottle design is shared across the platform regardless of engine.

Key Features:

• Direct replacement for OEM part number 4G0121403AG
• Also cross-references to 4G0121403AC, 4G0121403D, 4G0121403G
• Manufactured to meet or exceed OEM specifications
• Durable construction
• Factory-style fit and function

Compatible With:

• Audi A6 C7 Saloon (4G2/4GC) 2.0 TDI, 2.0 TFSI, 3.0 TDI, 3.0 TFSI, S6, quattro variants – 2010 to 2018
• Audi A6 C7 Avant (4G5/4GD) 2.0 TDI, 2.0 TFSI, 3.0 TDI, 3.0 TFSI, S6, RS6, quattro variants – 2011 to 2018
• Audi A6 C7 Allroad (4GH/4GJ) 3.0 TDI, 3.0 TFSI quattro – 2012 to 2018
• Audi A7 Sportback (4GA/4GF) 1.8 TFSI, 2.0 TFSI, 2.5 FSI, 2.8 FSI, 3.0 TDI, 3.0 TFSI, S7, RS7, quattro variants – 2010 to 2019
• Audi A8 D4 (4H2/4H8/4HC/4HL) 2.0 TFSI Hybrid – 2009 to 2018

Year Range:

2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019

This is an aftermarket replacement part, not a genuine Audi component.