2011 Subaru Forester - oil smell in passenger compartment

sometimes get an oil smell in the passenger compartment. I’m able to stop the smell by pressing the air recycling button so that no outside air enters the compartment. I’ve checked the engine for leaks and found none. A friend suggested that it might be the 0w20 oil, the oil being so thin.
Anyone else experiencing this?

Well, that is wrong. You have a leak that you just can’t see that is getting on the exhaust is a good possibility. It may take a mechanic and a lift so it can be seen underneath.

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I used to own 2007 Outback, where the passenger side CV driveshaft leaked a little bit on the inside joint.
It was spewing drops of grease on the hot exhaust, which was located few inches away from it, right in the “spray path”.
The smell was sucked into the passenger compartment too.
The fix was to replace the boot.
If you happen to have something like this, do not install non-oem shaft, it is a very high chance to get a bad vibration at idle when gear is engaged - OEM shafts have a spec on the extra “free play”, which aftermarket parts often do not meet.

Another possibility is that the PCV valve is gunked-up, thus causing high pressure within the crankcase. In that type of scenario, it is possible for oil to be forced out from a gasket or two.

The PCV valve is probably the cheapest engine part that exists, but for some reason it is overlooked by all too many car owners and mechanics.

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