From Mike D.
Hey, I just had the exact same thing (as other Mike) happen this morning. I woke up and smelled a weird burning type smell, almost sulfuric. I went and noticed it was the sump pump area. Unplugged it and opened it up – noticed a layer of oil at the top of the water, and the smell was pretty bad. It has been off for an hour now and there is a small but consistent stream of oil bubbling from the motor to the top of the water.
I did research and am almost certain that is the issue and water got into the motor effectively burning it out and causing the smell. I emailed my condo corp to send someone out, hopefully it is covered.
As for removing the oil, I may just have to do that manually with a bucket and then clean the pit with bleach afterwards?