Coolant Pipe / Aluminum Engine Cooling System Hardline – 06M121661D

Original cooling system return pipe (rigid water line with flange and elastomer connector), designed for Audi A7 Sportback (4K / 4K8 generation) and Audi A6 C8 (4K2 / 4K5 / 4KA type) with 3.0 V6 TFSI turbocharged petrol engine (55 TFSI designation / EA839 family / DLZA, DKMB and related codes), as well as related models based on the modular longitudinal platform MLBevo.

Original VAG cooling system component. Made of precision-bent aluminum alloy with high thermal conductivity and thermomechanical resistance, connected to an EPDM reinforced rubber section clamped with a factory spring clamp. Finished with a massive, two-hole mounting flange with a seat for an O-ring seal. It is completely resistant to the extreme temperatures in the V-engine engine compartment, high operating pressure, and prolonged contact with engine coolant (G12evo / G13). It is responsible for the rigid, failure-free transfer of coolant in critical areas of the 3.0 V6 unit block, eliminating the risk of leaks and deformation.

Technical specifications:

• Catalog part number (OE): 06M121661D / 06M 121 661 D (interchangeable with revisions in the 06M121661, 06M121661A, 06M121661B, 06M121661C series)

• System / Category: Engine cooling system (Engine Cooling System / Coolant Hardline Line)

• Function: Rigid water line / V6 engine coolant circulation pipe (Coolant Pipe)

• Dedicated engine: 3.0 V6 TFSI (55 TFSI / EA839 family) and related 2.9 V6 TFSI units (S6 / S7 / RS4 / RS5)

• Design: Formed aluminum with a two-hole mounting flange, O-ring groove, and reinforced rubber connector with a factory clamp

• Installation side: Engine compartment – directly on the engine block / 3.0 V6 TFSI power unit accessories

• Steering side: Left (LHD – European version) and Right (RHD) – universal component

• Condition: Original used part (100% functional, leak-tight, unobstructed, aluminum section straight without dents, mounting flange flat and undeformed, O-ring seat clean without corrosion, rubber connector flexible and without cracks)

• Manufacturer: Audi AG / VAG (OEM Original)

Main application:

• Audi:

  • A7 Sportback (4K8 type) – model years 2018 to 2026 (3.0 TFSI / 55 TFSI engines)

  • S7 Sportback (4K8 type) – model years 2019 to 2026 (2.9 TFSI engines)

  • A6 / A6 Avant / Allroad (4K2 / 4K5 / 4KA - C8 type) – model years 2018 to 2026 (3.0 TFSI / 55 TFSI engines)

  • S6 Avant / Sedan (4K - C8 type) – model years 2019 to 2026 (2.9 TFSI engines)

  • A4 / S4 / A5 / S5 (8W / F5 - B9 type) – 3.0 TFSI engines (354 hp / 450 Nm)

  • Q7 / Q8 (4M / 4MN type) – 3.0 TFSI versions

  • Porsche: Cayenne / Panamera (9YA / 971 type) – 3.0 V6 Turbo engines (EA839)

Fitment guarantee and VIN verification

Every pipe undergoes mounting flange geometry verification, obstruction check, and pressure leak test before shipping.

Fitment / installation tip: The initial 06M designation assigns the component directly to the EA839 engine family. The rigid OEM profile ensures a perfect fit into the mounting holes in the engine block without causing any stress on the bolts. Before installation, it is recommended to install a new O-ring sealing the flange and lubricate it with engine coolant. Before purchasing, we recommend comparing the full OE number with the index (D) on the sticker or marking on the part body, or verifying it using the vehicle's VIN.