Peugeot 2008 II: Flickering Check Engine Light and Rough Idle Explained

Why the light flickers with a rough idle

On a Peugeot 2008 II, a check engine light that flickers rather than stays steady is usually the ECU reporting an active misfire. The engine is not burning fuel cleanly in one or more cylinders, so you feel the shake at idle and the ECU flashes the light to warn you. It can be intermittent at first — worse when cold, damp, or under light load — but it rarely fixes itself. On the 1.2 PureTech petrol, ignition and fuel delivery are the usual suspects; on the 1.5 BlueHDi, injector and EGR faults deserve a closer look.

What to check first

• Fault codes and misfire counters: scan all modules and note which cylinder is missing; don’t just clear the light.
• Spark plugs and ignition coils: the most common cause on PureTech petrol models — swap coils to see if the misfire moves.
• Injectors and fuel pressure: direct-injection petrol and diesel injectors can cause rough idle and a flashing light.
• Intake leaks and PCV system: a split hose, leaking intake gasket, or failed PCV diaphragm leans out the mixture at idle.
• Throttle body and carbon buildup: a dirty throttle body or carbonised intake valves can make idle unstable, especially on direct-injection engines.

Is it safe to drive?

Treat a flickering check engine light as a short-notice warning, not a “book it in next month” light. A steady light is often okay to drive gently to a garage; a flashing or flickering light means raw fuel may be reaching the catalytic converter, which can damage it quickly. If the car is shaking badly, smells of fuel, loses power, or the light flashes continuously, stop safely and get it recovered. Otherwise, keep the revs low, avoid hard acceleration, and have it scanned as soon as possible.

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