E39 540i Ticking Problem

[HardStep]

Hi guys,
have been very busy last weeks and as my 540i is not my daily driver, it has been staying in garage for laike 10 days. Tonight i was going to have a ride and after backing it out and left idleing, i noticed interesting ticking sound, i've never heard before.
It sounds like hot exhaust pipe, not metal clicking against metal. Did not notice any irregularities in idleing though. Decided not to drive the car tonight to the meeting and drove it back to garage, where i noticed the headlights and gauge cluster going lighter as i pressed the gas petal.
I don't have time to go to service for a while but would prefer not to have sleepless night until i get there.
Might there be something with alternator or charging?
Thanks.

[///Matt]

To me it sounds like the alternator. The alternator may have a ticking sound due to it's ball bearings hitting each other. It may be fried. Have a mech check it out.

[HardStep]

Had 5 minutes today to start the car for once more. There was a small buff of smoke coming from the passenger side under the hood (while open) and the ticking increased with rpm.
What can i do to check the alternator on my own?
Also, there are remanufactured alternators available in the net for under $200 but as i've read, these remanufactured are 50/50, you might need to buy new one soon. Any suggestions, where to order from? And as i remember, there are two manufacturers, are both parts interchangeable?
Thanks.