XSeries-forum

In reply to would you need a new gasket, if it was put on properly and torqued to 10Nm then you could probably use it again, my experience is people put them on and graunch them to god knows what torque, bit it like tyre fitters/air guns and wheel bolts

I think it's probably a dicky lifter - although it's always worth checking chain guides especially at the mileage you're on.

In any case should you decide to take it apart to change the lifter you may aswell do the guides whilst you're in there.