Why does the car feel sluggish after just being serviced?
2 Answers
Just after servicing, the car feels sluggish because the engine oil has not yet reached the lubrication surfaces of the engine, and the internal components of the engine are not fully lubricated, hence the sluggishness. Engine oil is the lubricant used in the engine, composed of base oil and additives. Engine oil serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and act as a shock absorber. Base oil is the main component of lubricating oil, determining its basic properties, while additives compensate for and improve the shortcomings of the base oil, imparting new characteristics, making them an important part of the lubricating oil.
I've encountered the issue of lack of power after maintenance multiple times. The most common causes are overfilled engine oil or incorrect viscosity. For example, if the factory recommends 5W-30 but the maintenance shop uses a higher viscosity 10W-40, the poor oil flow increases engine resistance, making the throttle feel like dragging a sandbag. Another possibility is improperly installed air filters blocking airflow, especially if the clips aren't secured properly - the engine can't breathe properly and loses power. Spark plugs that are either too tight or too loose can affect ignition; I've seen cases where apprentices used impact wrenches to force spark plugs, causing air leaks. Another potential cause is the ECU resetting after battery disconnection during maintenance, temporarily making throttle response sluggish (this usually resolves after driving about 20km). Of course, clogged fuel filters aren't uncommon either, particularly when new filters are installed without properly bleeding the fuel lines.
