Lights flickering

330XI 195k MILES, replaced alternator under a yr ago

I start the car and immediately notice that while in park the headlights (including the side lights) flicker every second. So for one second its normal lights, then it dims down for a second and then goes to normal lights, and so on. With the dimming in and out, the lights coincides with the idle which goes from approx 500RPM (dim) to 600RPM (normal) and repeat. So its a constant phase every second.

Now when I put the car in drive with my foot on the brake, same thing, except maybe 1.5 seconds phase.

When I am driving the car at night, I notice the lights dimming in and out as well, especially on straight aways.

Coincidentally my right headlight just went out a few days ago and I replaced it and today my driver front headlight went out as well. I use sylvania silverstar and they generally don't last long, however I'm wondering if this dimming problem has something to do with it.

Any thoughts?

i would make sure your battery and alt are working/charging properly for starters

If they are xenon maybe the ballasts are trying to retire.

Headlights are H7

Did you check the alt. and bat. likr Captain Oversteer suggested? Results?

Check your taillight wires. They overheat and short out and will cause your headlights to flicker. Its a common fail point...do a search on it and you will find the fix.

OH, and stop using Silverstars - they have a short lifespan. I kept replacing mine every 3-6 months before I went back to stock bulbs.