OVERVIEW
Genuine VW/Audi 7L6-121-157-J is an individual coolant hose with a quick-release coupling for the matching cylinder-head coolant-pipe connection. It renews that assigned hose on the confirmed BAR 4.2 FSI Touareg and Q7 applications below.
Technical details and what is included
- Factory part number: 7L6-121-157-J / 7L6121157J.
- Component type: formed coolant hose with quick-release coupling.
- Assigned engine family: original BAR 4.2L FSI gasoline V8 arrangement.
- Quantity supplied: one hose assembly with its coupling.
- Mating coolant pipe, additional circuit hoses, separate mounting parts and coolant are separately specified.
The archive photo shows the hose shape and coupling/retention arrangement. Match the original pipe connection, hose routing and J revision before ordering. A hose used on a VR6, diesel or earlier non-FSI V8 cooling circuit requires separate verification.
Common reasons to replace
- A diagnosed coolant leak from this hose or coupling.
- Cracking, splitting or other visible hose damage.
- A damaged quick-release fitting or retention feature.
- A distorted or compromised hose discovered during cooling-system service.
Inspect the mating coolant pipe and connection surfaces separately. A cracked pipe, damaged sealing surface or fault elsewhere in the cooling system requires its own repair. Confirm the leak location before replacing a hose, and inspect adjacent connections while the area is accessible.
Vehicle fitment
These vehicles require the original BAR 4.2 FSI cylinder-head coolant-pipe arrangement. Model name alone does not establish cooling-circuit fitment.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Volkswagen Touareg | 2007–2009 | 4.2L FSI gasoline V8; BAR | 7L facelift; original BAR cylinder-head coolant-pipe connection; Original six-speed automatic; 4Motion | Original coolant hose with quick-release coupling assigned 7L6121157J. BAR FSI engine only; earlier non-FSI V8, VR6 and diesel cooling circuits excluded. One hose with coupling supplied; mating coolant pipe, additional circuit hoses and coolant are separate. |
| Audi Q7 | 2007–2010 | 4.2L FSI gasoline V8; BAR | 4L; quattro; PR-T8T; Original six-speed automatic | Original PR-T8T cylinder-head coolant-pipe hose with quick-release coupling assigned 7L6121157J. Gasoline FSI V8 only; 3.6L, 3.0L TFSI and diesel circuits excluded. One hose with coupling supplied; mating pipe, additional hoses and coolant are separate. |
Installation and service guidance
Follow the factory cooling-system repair procedure and allow the engine to cool before opening the circuit. Release pressure and drain coolant as directed for the assigned repair.
Remove the hose without damaging the mating pipe, compare the new routing and fitting with the original, and inspect the connection surfaces. Install the coupling and any separately specified seals or clamps according to the factory procedure, ensuring the retention feature engages correctly.
Refill with the vehicle-specified coolant and concentration, complete the required filling/bleeding procedure and check the repaired connection for leaks. Verify operation under the factory test procedure after the repair.
Use the vehicle repair information for exact connection preparation, clamp placement and filling requirements. This listing supplies the hose assembly only and contains no coolant or other service fluid.