2004 toyota highlander 4cyl high miles 220k . replaced long overdue leaking valve cover gasket and after finish started car and got instant lifter ticks. never did this before and always ran quiet and smooth. looked under car and oil was pouring out front of engine. from front crank seal. could have resealing the valve cover gasket cause an increase in crankcase pressure an d caused the worn crank seal to give out suddenly? this car has the infamous oil burning engine and has used oil since 150k and would expect some serious blowby by now