When I bought this car from a used car dealer a few years ago it had its share of problems to which i new when i bought it and had intentions to take care of every one .After that was all said and done a new situation came up.On this automatic transmission when you shift from park to drive the engine / trans is making a rumble noise. Shifting it back into neutral or reverse or park it smooths out ,this all takes place with the car not moving.I have taken it to my trusted mechanic and he said it’s nothing to worry about.The car has 100,000 miles on it and runs very well ,I’m thinking this may be a torque converter issue .Was wanting to ask if you or any of your subscribers have experienced any issue like this on a late model Outback Subaru. Really do like this car but got to draw the line somewhere on repairs.
It might just be worn transmission or engine mounts.
check your front CV shafts - if these are aftermarket (tell-tell sign: joints are not painted), it will make for these symptoms due to reduced free-play in joints of typical/cheap non-OEM parts
another thing: if ATF was not replaced on schedule and/or was not replaced with proper ATF-HP fluid, torque converter might be introducing some vibrations
it is a good idea to check engine/transmission mounts too