DIY – BMW Z4 (E85) halogen headlight bulb replacement


October 26, 2017 by

Replacing a halogen headlight bulb in a BMW Z4 (E85) is a simple DIY task that you can complete in 30 minutes.

The halogen headlight bulbs in my Z4 last about two years before they burn out or get obviously dim. Fortunately, replacing them is an easy task.

Some people recommend replacing both bulbs at the same time, since they often last about the same amount of time before failing. New bulbs can also vary in brightness from bulbs that have been in service for a while. If you are changing bulb brightness or color temperature, you must replace both at once. Bulbs are often sold in pairs. If you only replace one, you can store the remaining bulb in its original package for later use.


  • While this procedure shows low-beam bulb replacement, the process for replacing high-beam bulbs is similar.
  • While the basic bulb-replacement procedure should be similar for any BMW with halogen bulbs, the Z4 has added steps because the headlights are accessed from the inside the front wheel wells. (Bulbs for an X3 (E83), for example, are accessed from the engine compartment, the right side requiring removal of the windshield washer tank.)
  • This topic contains:

    Tools and Time

    • Tools: Flat-bladed screwdriver (or a coin)
    • Parts: H7 halogen bulb
    • Time: 30 minutes
    • Difficulty: Easy

    Bulb selection

    Note: Many vehicles offer multiple headlight options. Make sure that you order the correct bulbs for your vehicle. My BMW 2007 Z4 with halogen projector beam low beams used H7 halogen bulbs for both low-beam and high-beam.

    Headlight technology has improved greatly. While halogen bulb technology provided is much better than the incandescent sealed-beams that preceded it, halogens have been surpassed by more recent bulb technologies, such as Xeon or LEDs.

    Unfortunately, you can’t just simply replace your halogens with bulbs of a different type, even though you can buy them. Headlight reflectors and projector are designed for a specific kind of bulb where the lighting element is in the exact same location. Swapping a halogen bulb for a Xeon bulb (with associated electronics) moves the bulb focus point, which can have an adverse effect on bulb performance.

    If you are interested in performing a complete halogen to Xeon projector beam conversion, including new Xeon projection units, see DIY – Xenon HID headlight upgrade (BMW X3).

    All halogen bulbs are not created equal! While many H7 bulbs are available, they do vary greatly in performance. When selecting a replacement bulb, consider the following:

    • Bulb wattage: Halogen bulbs are sold in several wattages. Use the same wattage as was originally installed in your car (typically 55-watts). The electrical system in your car is designed for a specific bulb wattage. Using a higher wattage bulb can blow fuses or melt wires and components.
    • Bulb color: Bulbs are assigned a color temperature which indicates the apparent whiteness of the light it produces. Bulbs typically range from yellow (lower temperature) to violet (higher temperature). Selecting a bulb that is white yields the best performance and does not attract undue attention from the police (yes, some bulbs are not legal for use on the street).
    • DOT compliance: You want to make sure that the bulb you select is listed as DOT compliant, meaning it is designed for on-road use. Bulbs that are not DOT complaint are designed for use in off-road vehicles and you run the risk of getting ticketed or having your vehicle impounded if you use them on the street.
    • Bulb cost: As with most things, if you buy cheap, you get cheap. Be wary of bulbs that are very inexpensive, as they often have diminished performance (shorter life and less brightness).

    I’ve been using PIAA Extreme White Plus H7 bulbs, 55-watt with a 4000K color temperature, for several years. While not as bright as Xeon, these bulbs do perform better than the H7 bulbs that came with the car. As noted on the box, the 4000K color temperature yields a bulb with an effective brightness of 110-watts. Also note that these bulbs are DOT compliant, meaning they are legal for on-road use.

    PIAA Extreme White Plus H7 bulbs

    You can purchase a PIAA Extreme White Plus H7 bulbs from Verify bulb compatibility with your specific vehicle before placing the order.

    Replacing the bulb

    Complete the following steps to replace a halogen headlight bulb.

    You can also watch a detailed video of this headlight bulb replacement procedure on the new QuirkyUncle YouTube channel.

    1. Turn the wheel fully outward to access the headlight access panel (red arrow).
      Z4 headlight access panel location
    2. Open the access panel release tabs.
      Z4 headlight access panel clip location

      To open the release tabs, rotate them one half turn counter-clockwise. Do not force them! They can easily break!

      Z4 headlight access panel clips

    3. Rotate the access panel away from the inner fender; then, slide it outward to remove.
      Z4 remove headlight access panel
    4. Disengage headlight rear cover latch (red arrow). It must slide off of the two raised notches (white arrows). Use a screwdriver to pry it, if needed.
      Z4 headlight cover latch removal
    5. Remove the headlight rear cover. You will need to wiggle it around to free it.
      Z4 headlight cover removal
    6. Remove the socket and bulb. Rotate the socket a quarter turn counter-clockwise until it is past the retaining clips; then, slide the bulb and socket backward.
      H7 socket clips
    7. Remove bulb from socket. The bulb fits tight. You will need to rock the bulb from side to side as you pull it away from the socket.
      H7 halogen bulb removal

      IMPORTANT: Do not touch the glass of the new bulb with your fingers. Oil from your skin will cause the bulb to fail prematurely. If your skin does touch the glass on the bulb, wipe it clean with an alcohol wipe before you install it.
      H7 halogen bulb handling

    8. Install new bulb in socket. The bulb only fits in the socket one way. Align the tab on the bulb with the tab on the socket prior to insertion.
      Z4 H7 halogen bulb key tabs
    9. Press on metal edges of the bulb until it is fully seated in the socket.
      Z4 seat H7 halogen bulb
    10. Carefully insert the bulb into the rear of the headlight assembly, aligning the tabs on the socket with the retaining clips on the headlight assembly; then, rotate the socket a quarter turn clockwise until it engages the retaining clips.
      H7 socket clips
    11. Turn on headlights to make sure the new bulb is functioning.
      Z4 headlight
    12. (Optional) Remove the headlight cover latch wire. Removing this wire makes it easier to install the headlight rear cover.
      Z4 headlight cover retaining latch removal
    13. Install the headlight rear cover. Have patience! Getting it in place can be tricky!
      • First, fit the tab on the inner end of the cover into the slot on the headlight housing (red arrow).
        Z4 headlight cover install 1
      • You will need to work with the cover a bit to get it to fit in place.
      • Make sure the cover seals all the way around its perimeter before securing the cover latch.
    14. (Optional) Install the headlight rear cover latch wire, if it was removed. Location of the latch wire mounting holes are shown below.
      Z4 headlight cover retaining latch mounting holes
    15. Engage the headlight rear cover latch (red arrow). It must snap into the two raised notches (white arrows).
      Z4 headlight cover latch install
    16. Make sure that both release tabs on the access panel are open.
      Z4 headlight access panel clips
    17. Inserting the long tabs on the access panel into the slots on the inner fender; then, rotate the access panel into place.
      Z4 install headlight access panel
    18. Close the access panel release tabs by rotating them one half turn clockwise.

      Z4 headlight access panel clip location

    Hope this article brightened your day! Drive safe!

    Did you find this posting useful? Did it save you time or money? If so, consider making a donation.


    • Updated date - Update text.



  1. frank wessel says:

    the amazon website indicates the H7 PIAA bulbs above are not compatible with the ’08 E85 Z4

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