Mercedes-Benz C280 hard start and irregular idling despite new parts on Mercedes-Benz C280

Some Mercedes-Benz C280 owners report experiencing hard starting and irregular idling issues even after installing new parts. These problems may stem from worn-out spark plugs or faulty ignition coils, which can lead to rough idling and misfires. Additionally, restrictions or clogs in the fuel system, including the fuel filter, fuel lines, and fuel injectors, can hinder starting and idling performance. Some owners also find that low fuel pressure, which should be verified against manufacturer specifications, contributes to these difficulties. An imbalanced air-fuel mixture is another factor that may cause irregular idling and starting problems. Furthermore, malfunctioning sensors, including O2 sensors, can significantly impact engine performance and lead to idling issues. Regular maintenance is crucial for older C280 models, as it helps prevent common issues associated with aging components. If symptoms such as a check engine light, rough idling, or poor fuel economy are present, the O2 sensor may require inspection or replacement. Addressing these key areas can help owners troubleshoot and resolve their vehicle's performance issues effectively.