One problem related to engine oil leaking has been reported for the 2006 Volvo S40. The most recently reported issues are listed below.
Found complaints on multiple sites about issue found on my vehicle . The oil filter housing corrugated breathing hose was so badly rotted was only little piece left rest fell off somewhere while operating vehicle. On top of that issue im ssuming due to thiss problem and it on going until I got check engine light it has caused oil filter housing itself to go bad im assuming in part to all oil build up from hose missing causing vacuum issues' why isnt his car that has same issue as others that were recalled with same exact operating and looking part with same exact hose rotting issue causing oil filter housing to become built up with gunk causing leaks both air and oil. . . . Pleae answer these issues for it shows how much Volvo cares about quality of there products.