Bear with me, this is kind of a long question...
A month ago, at the time of an oil change, my '01 Outback was due for a new timing belt (at 105,000 mi.), and I took it to the Subaru dealer's garage and had the new belt installed. Ever since, when I idle or after I turn off the car and get out, my engine emits a sort of burning rubber smell. So I took the car back to the dealer and mentioned the problem. He found oil around the head gasket, suggested I might have a leak. I told him that several months ago, another mechanic botched an oil change, mis-installing the filter, which leaked and sprayed oil all over my block. So the Subaru technician cleaned off the gasket residue, took it for a 15 min. drive, checked the gasket again and found no oil leaking. So it may NOT be a leaky gasket, BUT a day later I'm still getting the smell.
My questions: Is it possible that oil from that earlier botched filter is still burning off in places? At the time, I smelled it for many days, then it went away. Now it seems to be back.
Or should I be really worried about my head gasket? What else could be wrong?
Other recent activity: Snow tires were installed two months ago, at which time I needed a realignment.
I bought this Outback six months ago.
Thanks for any light you can shed on this issue.