Vehicle leaked small amounts of oil. Had oil changed and still leaked. Mechanic thought it was from oil pan, used die to locate leak, said it was front timing cover seal. Now has quoted front timing cover seal plus crankshaft seal replacements at $475 (most of this is labor which I understand) and may be another $100 to replace oil pan seal if there is still signs of a leak. Assume it is difficult to locate source of leak...have you had similar experience? Anything else that should be checked for leaking while he has access?