We have a 2005 S80 2.5 T with about 90,000 miles. The car often emits a sort of hot oil smell - not like oil being burned in combustion but more like the smell if you drip oil on a hot manifold. There is no leakage to be found anywhere, nor any detectable smoke. I'm curious as to the possibility/likelihood that the turbo may be allowing oil to invade the exhaust stream. Does anyone have any experience in this department? If turbo leakage is possible, I don't want to risk fouling the cat or O2 sensor.