Has anyone had a head gasket failure in a 2.2 liter? I have a '99 OBS with 222,000 miles- funny smell (like a head gasket going; had a '00 OB with 2.5 & head gasket went and it had similar smell), but no oil leak that I can see and coolant level hasn't gone down much. Smell it especially in cold weather or in high elevations in summer. Could oil be leaking out of head gasket and burning itself off on engine? Would the Subaru Coolant Add On affiliated with the 2.5 liter recall help? Just changed the coolant last summer before going to Colorado. I know with the miles it just may be the life expectancy of the engine, but I don't know. Any ideas?