...a loose oil cap? The rubber gasket on my BMW 535’s oil cap cracked and fell off when I removed it for an oil change. I put it back on just to test the oil level and move the car from the middle of the garage, thinking that I’d just go and buy a new one on Monday. After the oil change, the car started heavily dripping oil. No apparent gushing from the oil cap, though. I use a Fumoto so I didn’t touch the oil pan bolt.
I could hear some air sucking from the cap. Covered the underside of the cap in Permatex, obviously BMW dealer isn’t open on the weekend for me to get a new one.
If that’s not the culprit, then the oil pan gasket decided to explode at the exact same moment as i changed the oil. Which, i guess, is possible.