Smoke was coming out of the hood at the end of a drive with my '85 240 DL (145K mi). I guess a seal gave out, as motor oil appeared to have sprayed against the firewall on the pasenger side, dripping down onto the exhaust pipe. Besides the embarrasment of a smoking car and a hot oil odor, I'm concerned about issues such as losing all the oil, engine fires, and other inconveniences.

After something like 15 miles, the gauge shows about 1 qt oil loss. Good thing it wasn't a 60 mile drive. Before I look at it to try to figure out where it's coming from, does someone know what is the most likely cause that I should check first?