Audi A6/S6 Coolant Reservoir / Tank / Bottle 4K0121405N

OEM Part #: 4K0-121-405-N (4K0121405N)

This page covers one exact OEM part number. Every unit we stocked has sold.

The coolant reservoir tank, OEM part number 4K0121405N, is a crucial component located within the engine bay of select Audi models, including the A6 Quattro, A7 Sportback, S6, and S7 from the years 2019 to 2021. This reservoir serves the primary function of holding coolant, ensuring optimal engine temperature regulation during operation. It interfaces directly with the engine and the radiator, facilitating the flow of coolant throughout the system. Common issues that may necessitate a replacement include leaks, cracks, or other forms of damage that can lead to overheating or coolant loss. This part includes the cap and is also referred to as a reservoir or tank. Additional compatible part numbers include 4K0121405AA and other referenced interchanges.

Specifications

Specifications for Coolant Reservoir / Tank / Bottle 4K0121405N
Fits Vehicle ModelA6, S6
Fits Vehicle MakeAudi
OEM Part No4K0-121-405-N (4K0121405N)
CategoryRadiator / Coolant

Compatible Vehicles

Fits 5 vehicle configurations across 1 make, 2019-2021.

Check your specific vehicle before ordering. This list shows year, make, and model. Some years have multiple trims or engines that use different parts, and individual listings may have additional fitment notes (e.g. “with sunroof only”). Review the full variant list below, or message us with your VIN and we’ll confirm the match.

Audi

  • A6 2019-2021 · 3 variants 3 with notes
  • S6 2020-2021 · 2 variants 2 with notes
View all 5 vehicle configurations — 5 with fitment notes
Full vehicle fitment list for Coolant Reservoir / Tank / Bottle 4K0121405N
Year Make Model Trim Engine Note
2019 Audi A6 Quattro Sedan 3.0L V6 Turbo For Vehicles with Production Date Between 04/16/18 and 09/07/20
2020 Audi A6 Quattro Sedan 3.0L V6 Turbo For Vehicles with Production Date Between 04/16/18 and 09/07/20
2020 Audi S6 Sedan 2.9L V6 Turbo For Vehicles With Production date Up To 09/07/20
2021 Audi A6 Quattro Sedan 3.0L V6 Turbo For Vehicles with Production Date Between 04/16/18 and 09/07/20
2021 Audi S6 Sedan 2.9L V6 Turbo For Vehicles With Production date Up To 09/07/20

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