Have a 09 Forester. Have oil leak. Had water pump, oil pan and now the cam seals replaced after four attempts. Cam seals were most recently replaced yesterday. It is still leaking a little. Will it take a week or so for the old oil to burn off on the undercarriage, or is there something still wrong. Also, with a Subaru at 100k, is it expected to leak a little anyway due to wear? Thanks!