My 92 Loyale (recently purchased) has a very distinctive engine vibration starting at about 65 mph/ (guessing 3500 rpm). I can best describe it as a consistent cycle (frequency) of about 1.5 seconds and decreasing in frequency proportional to an increase in rpm. This probably make very little so let me just say that it feels exactly like a bad harmonic balancer. It's definitely a harmonic vibration beginning at the speed I mentioned. Do Subaru's have vibration dampener problems? Is this a good diagnosis on my part? TIA
peter