Underhood smoking... need help with a diagnosis

[SlxAlxx]

I started my '89 Fleetwood Coupe today as usual just to warm it up. I turned on the a/c for the first time since it was involved in a front-collision in mid-October of '06. The air blew cold and the rpm's were going down because the engine had heated up. I turned it off and turned it back on about 10 seconds later just to see if having the a/c running made a difference. Right after the motor turned over, this began smoking:

I don't know why smoke would be coming out of there. The only thing I could think of is that the WD-40 that the previous owner coated the engine with was burning off. I just wanted to be sure of the actual problem.

[awadecki]

What part is smoking? Can't tell from your picture.

[SlxAlxx]

It's a part behind the throttle body (the round part of the air cleaner housing.) It's to the left of the tranny fluid dipstick and an air hose is connected to it.

[awadecki]

I think that's the air management check valve. It diverts air either into the catalytic converter or the intake depending on engine temperature and operation. No idea why it might be smoking (it's supposed to divert fresh air). Unless you notice it again, I wouldn't worry about it.