My 98 legacy outback engine has lost compression (one month before I pay it off ). I am considering what to do so I am asking for advice. Could this be a blown headgasket (I believe that it is the original and I am at 180,000 miles)? If so, how do I know it has? If it is something else, can I fix this engine or should I look at getting a different one? I would really appreciate help on this.