also ignition timing can cause it to run hot and knock, so check up on the crank shaft speed sensor or w/e the technical name for that is, or the the cam speed sensor w/e the 3.8 has. i don't think it's a distributor ignition. also check up on your knock sensor. your oil will smoke like that anyway, if it's really bad it could be just from a bunch of extra heat, or excessive blowby

 

Ugh, the site just ate my post. Sorry if it posts double but the site is acting really slow right now.

It could be coolant/air lock in the coolant system. Just dealt with it this past week with my Corsica. The car was overheating on the way home from work. Got home, check the oil and no coolant signs. Went got a thermostat and installed that. Took it out for a drive and it was overheating within 3 miles of the house. Came home and let it sit till it was cool. Then I opened the coolant reservoir and ran the engine till the thermostat opened at the proper temp. At that point it started gurgling and spitting all the air out of the system. Ran it for about 15 minutes at idle with the cap off to make sure it got most of it out of its system and filled as needed along the way. Now it has no problems with overheat. There's no telling how long that air was in the system as the car ran above normal temps (but not hot) on average. Now it's always under 50% on the gauge.