Range Rover Sport III: Why Your Check Engine Light Flickers at Idle

What a flickering check engine light with a rough idle means

On your Range Rover Sport III, a check engine light that flickers while the idle stumbles is usually the engine management system reporting a misfire — a cylinder not burning fuel properly. It can also be a lean-condition fault from a vacuum leak, a tired fuel pump, or a sensor sending shaky readings. Because the light is intermittent, don’t dismiss it: early misfires often show up only at idle or light throttle before they get worse.

Check these first

Start with a proper scan tool that reads pending, permanent, and manufacturer-specific codes, plus live misfire counters. Then inspect the basics:

• Spark plugs and ignition coils — especially on higher-mileage gasoline models; a cracked coil or worn plug is a classic cause.
• Intake and vacuum leaks — check the PCV hoses, intake boots, and purge valve for cracks or loose connections.
• Air/fuel sensors — MAF, MAP, and oxygen sensor readings that jump around can cause rough idle and flickering faults.
• Fuel delivery — low fuel pressure, a clogged filter, or a leaking injector can mimic ignition problems.
• Battery and grounds — these SUVs are sensitive to low voltage; a weak battery can make sensors behave erratically.

Is it safe to drive? If the light is only flickering now and then, the idle is mildly rough, and power feels normal, you can usually drive gently to a shop — but don’t ignore it. If the light flashes continuously, the engine shakes hard, you smell fuel, or you lose power, stop driving; a persistent misfire can overheat the catalytic converter and cause costly damage. Have the codes read before replacing parts, and fix the root cause rather than just clearing the light.

This material is AI-generated and for informational purposes only — it does not replace an in-person diagnosis by a qualified mechanic.