I have the dreaded piston slap in my leased 2000 outback. I was planning on purchasing it at the end of the lease. I have taken it to the dealer three times and each time I have been told that it is normal. Yes, after completely warming up the noise goes away. This usually takes 15 minutes or so. I can't believe that there is not some damage taking place inside the engine. The car only has 49K+ miles it. Should I be taking it through the Subaru appeals process? Have others gone through this?