So do you have an idea on why your entire oil filter cap comes off when you try to remove the drainbolt on the bottom of the oil filter cap? It's because torque specs were not followed on a previous oil change. The oil filter cap is supposed to be torqued to 25 N•m which is equal to about 18 ft.lbs. Use an oil filter cap wrench (I recommend the Motivx MX2320) to tighten the oil filter cap and use a ⅜ inch extension and ratchet to tighten the drainbolt on the oil filter cap to only 10 ft.lbs. Problem solved.