[User14]

I don’t get any smoke, but I get a smell of oil (maybe diesel) in the cabin, somedays stronger than others.
It is more noticeable when the Aircon is on auto and recirculate, or Aircon off, and just in Fan mode. There is no smell, if the vents are closed and the fan and aircon off.

I will occasionally notice it when I come back to the car and I've left the vents open and the engine has been off but cooling down.

Someone on the Volvo forum had a similar issue, suggested that
..",vaccum pump seal was leaking and oil was droping on top of the gear box” - not sure if I have the same problem.

I have changed the internal aircon filter recently, but noticed no change in the strength or frequency of the smell.

I have had a look at all the boot/door seals to no avail, and no obvious leaks or “sweats” in the engine compartment, but the important thing is there is no smell if the vents are closed, so it must be coming up from the vents.

The external air intake is from below the wipers and the whole climate system works very efficiently, the recirculate correctly filters out external road/other vehicle smells.
As a test, I placed a strong cherry air freshener in the engine compartment, to see if any smell would leak through from there to the cabin, and am yet to smell it, so importantly, that eliminates fumes from the engine compartment itself.

I have an inspection booked for Wednesday, so I will share what is discovered, if anything. The garage has suggested that there may be a leak/crack in a breather pipe, or other misc diesel leak.

As the above suggestion, I will check the injector seals.

NB: it is more noticeable/stronger if I am more liberal with the accelerator., and definitely only when the engine is not cold.

XC60 D4 AWD 2013