الكربون يعيق إبرة صمام إعادة تدوير العادم

Carbon built up around the recirculation valve's pintle and seat, binding it. It is the specific mechanism behind most recirculation valve faults — the pintle sits directly in the exhaust stream and the deposit is a matter of time rather than a defect.

Binding rather than seizing is the common state. The valve still moves, slowly or partway or with a jump as it breaks free, so the module reports a position not reached in time rather than a dead valve. A fault that appears cold and eases as the engine warms is binding, since clearances open as things expand.

Held off its seat is the version the driver feels — exhaust gas entering at idle gives a rough, hunting idle and a hesitation pulling away. Check the pintle closes fully and moves smoothly by hand with the valve removed. Cleaning is a repair with a lifespan: the deposit returns unless what produces it changes, so a vehicle doing short cold journeys will meet this again.