2000 pontiac grand am 2.4

Just recently swapped engine the old one was seozed up tight. (Bought the car w seized engine. Put a new salvage yard engine and the car is smoking like crazy. Has what looks like black old oil leaking out of the tail pipe/muffler. Car has beem idling for an hour w no overheat. Looks like oil kind of feels water though. I can tell the car has sat for a long time.

New engine runs really well holds idle at 700 rpms. But smells horrible.