Subaru Forester - Hissing noise (engine compartment) | HELLA

If the problem described above is detected, the cause could be a defect (split / crack) on the suction hose in the connection from the intercooler to the throttle housing.

Remedy:

In order to exclude other sources which might be causing the problem, first check the acoustics and then run a visual inspection of the engine compartment. Pay particular attention to any form of damage, check for a snug fit of components, look out for any soiling (oil, ...) and the like.

In this case, as described above, the suction hose is damaged (a crack in the area marked, Figure 1).

Replace the damaged suction hose with an improved variant of the hose as per manufacturer's instructions.

Suction hose: OE No. 21869AA130