Replacing Faulty E89 BMW Z4 Tail light
BMW Z4 owners know the struggle: as soon as you fix one issue, another one pops up. In this case, it’s the rear indicator light—a common problem caused by a failing LED strip inside the tail light unit. Unlike regular bulbs, the Z4’s indicator isn’t replaceable on its own, meaning you’ll need to swap out the entire tail light assembly when it fails.
If your rear indicator has stopped working, flashes inconsistently, or you’ve noticed condensation or water inside the housing, this guide will walk you through everything you need to know—from diagnosing the issue to safely replacing the tail light yourself.
Why BMW Z4 Rear Indicators Fail
The Z4 (especially the E89 model) uses LED strips for the indicators. When they fail, it’s usually because:
Water enters the tail light housing due to a broken seal
Moisture damages the internal LED strip
The LED circuitry burns out (can’t be replaced individually)
Age and weathering wear down the tail light unit
The result? Flickering or dead indicators—and a mandatory MOT failure if left unfixed.
The Problem: Rear Indicator Not Flashing
During a quick test of the hazard lights, one indicator works perfectly, but the other either:
✔ Works sometimes
✘ Doesn’t flash at all
✘ Or flickers weakly
This inconsistent behaviour confirms LED failure inside the tail light.
Since the LED is built into the unit, you cannot replace it separately. You must swap the entire tail light assembly.
Cost of Replacing a BMW Z4 Tail Light
BMW dealership quote: £372.96
Online (aftermarket or OEM-style): £200–£250
Dealers won’t share part numbers (for obvious reasons), so the best approach is to remove your old unit and check the part number directly.
Step-by-Step: How to Replace the BMW Z4 Tail Light
1. Access the Tail Light
Start by opening the boot and placing the car into service mode to access the rear panels.
Remove the surrounding boot trim pieces—look for hidden tabs, clips, and screws. Some trims require gentle prying, others need a bit of force.
2. Remove the Old Tail Light
After removing the inner trim:
Disconnect the electrical connector
Remove the bolts securing the tail light
Gently push the light unit outward
Wiggle and pull until it comes free
Once removed, locate the part number on the back of the housing for correct ordering.
3. Install the New Tail Light Unit
When your replacement arrives:
Unbox carefully
Align it with the same guide slots the old unit sat in
Slide it into place from the outside
Make sure the rubber seal sits outside the car body, not tucked inside—this prevents water leaks
Reconnect the wiring harness
Tighten the bolts
Reinstall all trim panels
4. Test the Indicators
Turn on the hazards or indicator stalk to ensure:
Left indicator flashes
Right indicator flashes
Brake and reverse lights still function
If everything works, your new unit is installed correctly.
Final Thoughts
Replacing the rear indicator on a BMW Z4 isn’t as simple as changing a bulb—but it is a straightforward DIY job once you know what’s required. By sourcing the part online, you can save £100–£150 compared to dealer prices.
If you’re tackling multiple repairs (like many Z4 owners), this is one of the easier ones—and one that instantly improves both safety and aesthetics.