buld may be sorting out on the earth or the eliment is going check the wires are good on the plug and the earth is clean. 
There isn't a filament (presume that's what you mean by element) in a HID bulb, it's an arc.
yep element in side not filament says on box i got with some old knakerd ones, it say lighting element.
Wrong as VXL V6 says HID Xenon bulbs do NOT have a filament or an element inside - light produced by an arc.
See the following extract re HID lighting - "Xenon HID kits produce 300% more light than standard halogens, yet use less power. Xenon car headlights are significantly different to conventional halogen bulbs that use a heated tungsten filament. Unlike Halogen lamps, Xenon HID kits don't have a filament but create light as a result of an arc between two electrodes. The heat from the arc vaporises the metal halide which produces light as the temperature and pressure increases.
The light produced by Xenon car headlights is greater than a standard halogen bulb and with less power consumption. On the road, Xenon HID kits appear as a bright white beam which resembles natural daylight. The bright white beam offers greater visibility and road safety."
Do not confuse HID lights with xenon filled bulbs, which like halogen filled bulbs, do have a filament inside.