[Aerkuld]

I have heard a couple of people claiming to have a sticking lifter actuator after using 15W-50 Mobil 1 which is too thick when compared to the factory specification. Whether this was coincidence or not is not clear, but it can't hurt doing an oil change and refilling with the correct 0W-40 weight oil and see if the problem cures itself.
If not it might be worth taking it to an independent garage or another dealer to seek a second opinion. Maybe an independent may be able to fix the lifter instead of replacing it?
Sorry I didn't see this yesterday!