Frustrating (and potentially dangerous) headlight problem

crooner12

Member
Question 1 and context

Last month I purchased an '06 Z4 and noticed that the right headlight will sometimes not light up. This happens after I first turn on the headlights, turn them off, and then immediately try to turn them back on. Sometimes, both the left and right headlights do not turn on, even after having been on before. On the dash, I get the "bulb-out" warning light.

I usually have to turn all the lights on and off six or seven times before both decide to turn on again. I know that there is a certain re-strike time for HID lights, however this problem should have been eradicated in modern Xenon headlights (i.e. you should be able to turn them on and off and back on again on demand without waiting). I thought that it could be due to the cold weather (low 30's), however there are many cars around me that also have Xenon headlights, and they seem to work fine.

Obviously, this is a safety issue, since there is a chance that they may not work at night when I need them the most. What do you think the problem could be? Ballast? The car's still under the factory warranty, so hopefully any repairs should be covered, no? Does anyone else have (or had) this problem?

Question 2: My Z4 has two sets of projector-ish headlights. The outer-most headlights are for the main Xenons. However, there's the inner ones that just have a light ring around them, but don't project any light. Is this just my car, or are these supposed to actually project light?

Thanks!
 
In the US, the inner lights have no bulbs, just the halos. Modern HIDs are better, but there IS a certain cool off time before you can refire them. I would never try to switch them on/off/on. That simply shortens the life of the bulb-every on/off cycle does. These bulbs don't have a filament in them, they project an arc between 2 electrodes through a gas filled quartz glass bulb. It also takes a few seconds for the bulbs to come to full brightness (unlike halogens).
 
Smokin is spot on a xenon should not be cycled like you describe. OIfficially it's supposed to be on and off only every 15 minutes but in reality this is not possible as 'auto on' switches on and off in tunnels, car parks, etc. You'll be headed for a new set of bulbs at $100 a piece soon and the bulb might not be a warranty item.

I suggest a trip to the dealer to diagnose the problem, be it LCM, ballasts or other fault
 
Thanks for the insight. I agree, ideally, you shouldn't cycle them on and off again. I still think it's a bit odd, though since my friend can do this in his Acura TL no problem. We were experimenting the other night and his turn off and right back on again. I didn't realize that these bulbs are so damn expensive. But, if they're designed to last a long time, then I suppose it makes sense...
 
I have the exact same problem in my '06 Z4. I'd say about once every other week or so, the right headlamp will not fire. Sometimes, it will come on after a moment or two. Most times, I will need to cycle the lights off (I usually leave them off for 1-2 seconds) then back on. This always seems to do the trick. I plan to bring this up at my next scheduled waranty service visit.
 
ay8306 said:
I have the exact same problem in my '06 Z4. I'd say about once every other week or so, the right headlamp will not fire. Sometimes, it will come on after a moment or two. Most times, I will need to cycle the lights off (I usually leave them off for 1-2 seconds) then back on. This always seems to do the trick. I plan to bring this up at my next scheduled waranty service visit.


Bummer. Yeah, this is kind of annoying. I made an appointment with my BMW dealer the other day. From the research I've been doing, it's probably the ballast or igniter. Otherwise, the lights work fine...no flicker or weird colors. Go figure...
 
So, the problem turned out to be the bulbs themselves, not the ignitors or regulators. Now both headlights fire up right away and are quite bright. Surprising that the bulbs only lasted 2 years...
 
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