The Land Rover Discovery 4 is still revered by many “Landy” enthusiasts as a high-water mark in Land Rover's history, and remains a highly-prized vehicle combining interior luxury and a sophisticated on-road ride with very advanced off-road capability. The original Land Rover Discovery was introduced in 1989 as a less-expensive alternative to the Range Rover, and this remains true of its positioning in the Land Rover line-up today, even after the introduction of the very advanced Discovery 5 in 2017.
Discovery 4 model life cycle
The Discovery 4 was introduced in the UK in 2009, and arrived here the following year, with sales success following right away. It featured some very sophisticated technology, including the now-famous Land Rover Terrain Response system, which enables drivers to tailor the suspension and drivetrain settings to terrain-specific needs, at the twirl of a console-mounted control knob.
The Discovery 4 was initially available here with a V6 diesel or in V8 petrol form, but the V8 engine was later dropped due to its profligate fuel drinking habits. Latterly, the Disco 4 came with a choice of 3.0-litre supercharged V6 petrol and V6 turbodiesel engines, with an eight-speed automatic gearbox being introduced later in its life cycle.
The new Discovery 5, with its much “softer” appearance, replaced the Discovery 4 in 2017. Traditionalists still rate the Disco 4 very highly, and they're well-represented on AutoTrader, with more than 200 listings for used examples.
How to change a headlight bulb on a Discovery 4
Changing a headlamp bulb on a Discovery 4 is a simple task, but there are a few “tricks” that you need to know. The first consideration is that the left-hand-side light bulb is far easier to access than the right-hand-side bulb.
To access the right-side bulb you will first have to remove the engine’s air-filter housing. This is not a difficult task, but you will need a good-quality screw-driver to disconnect some hose clamps fitted to the housing. Once all hose clamps and any other fittings to the housing are disconnected, the large housing can simply by pulled out as it is located on the right-side of the engine bay by prongs that slot into grommets.
However, care should be taken not to damage important electrical cabling that is located around the air-filter housing. Consult a dealer if you are at all unsure about how to do this job.
With the air filter housing removed you can access the right-hand light bulb as you would the left-hand side.
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Step-by-step bulb replacement
1. Open the bonnet by using the lever located next to the door opening on the front left-hand-side of the passenger compartment, below the cubby hole and ahead of the door aperture.
2. The left-hand-side headlight bulb is much easier to access than the right-hand-side one. No tools are required for the left-hand-side bulb replacement, but you will need a torch.
3. If the right-side bulb needs replacement, you first need to remove the air-filter housing. This is not a difficult job and the only tool required is a flat screwdriver, for loosening the clamps that secure ducting pipes. Care has to be taken not to crimp or damage any wiring that snakes around the filter housing. If you are at all unsure how to do this, we recommend you take it to a dealer or specialist workshop.
4. We conducted our bulb change on the left-hand-side lamp. The bulb is located behind a round black plastic cover that is clearly visible from the bonnet opening, and easy to remove by hand.
5. By pulling on the little plastic tab located on the rim of the cover, it simply pops out to reveal the opening to access the bulb.
6. Use a small torch to illuminate the bulb location inside the light recess. The bulb has a flat-faced aluminium housing with manufacturer markings on it, and a cable attached to it.
7. The bulb is located in the lamp housing by small plastic clips fitted on either side of the bulb, behind the rectangular aluminium bulb housing. These are not easy to see, and it proved impossible to photograph these two clips clearly, due to access problems. (Our picture shows arrows where these are located, behind the flat metal bulb housing). The bulb is released by simply squeezing in these plastic clip tabs towards the bulb. The bulb is then withdrawn, without any twisting motion.
9. The cabling is then detached from its socket on the old globe, and plugged into the new globe.
10. With the cabling connected, the new globe is simply pushed into the lamp housing, making sure it is lined up in the same way the old one was removed. Push the new globe home securely until the retaining clips click into place. Wiggle the new globe gently to make sure it is secure.
11. The final step is to replace the bulb access cover securely, making sure that no dust or water can intrude. Check that the light operates properly and you are done!
