OK, several times since I got my car back, when I've started it, smoke comes billowing out the sides of the my hood.  After a while it stops, so it's unlike the time when the smoke started to come after I had driven it for a while.  But is it something really bad, like a leak onto the intake manifold, or the intake manifold itself?  I'm looking all over the Internet, and it's telling me the worst.

I don't know what to do with the car, again.  Any advice?