I see a lot of people using Seafoam in their engines just to get it clean and see if performance will be increased. Will adding Auto-Rx be better or should it ONLY be used if you need to remove engine sludge? Just wondering as I am considering using one of them when I hopefully get my 01 A4. I guess what Im saying is can I use it as a preventative measure? I heard that seafoam damages seals.

 

from what i know that is not true. seafoam did nothing but good things to my engine and many others have similar results. a few people have problems, like when seafoam works too well and they have a ton of deposits it gets rid of, sometimes those deposits can clog the O2 sensors. i cant comment on auto rx or other additives as i havnt tried them.

 

Not so much 'damage' as 'removes the sludge that was plugging the hole'. Sometimes it better to leave a high mileage, abused engine alone.