How to Replace the Diesel Filter on Audi A6

The diesel filter on the Audi A6 is located under the coolant reservoir. To access it, remove the reservoir by unscrewing the visible screw on the bracket that holds it and the upper plastic cover of the engine, which can be pulled off to detach it from its place.

Once these two components are removed, you will have easier access to the diesel filter, which has four hoses. The first two hoses on the left side can be disconnected only after loosening the metal clamps with pliers.

The other two hoses are attached to a plastic connector fixed to the filter with a metal clip, so simply pull this clip to remove the entire connector. After disconnecting the two hoses and the connector, you will notice two O-rings located at the bottom of the connector.

These should be removed with a flathead screwdriver and replaced with the new ones provided with the new filter. After this, loosen the bolt that secures the filter on its side; this will help loosen the strap that holds it. At this point, the old filter can be removed and replaced with the new one, making sure to reassemble everything in the reverse order of disassembly.

During the first startup, the car may struggle to start; this is because the new filter needs to fill with fuel again, so just keep trying to start it until it runs smoothly.