Went to do an oil change, like any other time I've changed the oil. Ended up dropping the cap, because it didn't want to come up through the engine bay, so I figured I'd pick it up off the ground. No biggie. Well, there's a spring-loaded plastic piece *inside* the plastic cap that does something with the flow of oil, it appears to be part check-valve, part compression to seal the cartridge filter to the block. When I dropped the cap, that piece popped out. It is only held in by some spring clips. The piece did NOT want to go back in, so I took out a socket and extension and pushed it against the floor. STILL nothing. So I grabbed a dead blow: Researching to find this POS and get one ordered because currently my jeep is now stuck in front of my house (I don't have my own driveway, it's shared). Also, it is now very broken, it was initially not that broken but I was really pissed off by then so I threw the whole assembly across the garage.