oil companies use different additive packages to come up with 5w30 which are incompatible. the new oil removes the old deposits in oil seals, ring landings etc. and replaces it with the new concoction and can cause leaks. when i went to mobil1 0w30 i had a miss after 50 miles because of a leaking spark plug boot seal. it went away. it can take up to an entire oil change cycle for the "new" oil to replace the old. when synthetics first came out in 1979 they would cause leaks even on a new car but the molecule chains are longer now and blaming synthetics for leaks on a 14 year old plus car is an old wive's tale.
thanks for the intel. you think just give it time and it will fix itself?