* Hard Starting: This is often one of the first and most noticeable symptoms. The engine may crank for a long time before starting, or may struggle to start, especially when cold.
* Rough Running/Hesitation/Stuttering: The engine may run rough, hesitate during acceleration, or even stumble and stall, particularly under load. This is due to an inconsistent fuel supply.
* Loss of Power: A significant reduction in engine power or acceleration is a strong indicator. The engine might feel sluggish and lack its normal responsiveness.
* White Smoke (Excessive): While white smoke can have other causes, excessive white smoke from the exhaust, especially when the engine is struggling, could point to insufficient fuel combustion caused by a blocked filter. Black smoke usually points to a rich fuel condition, which is less likely with a clogged filter.
* Check Engine Light (MIL): The malfunction indicator lamp might illuminate, usually accompanied by a diagnostic trouble code (DTC) related to the fuel system. You'll need an OBD-II scanner to read the code.
Important Note: Because many fuel system issues have overlapping symptoms, it's crucial to have a professional diagnose the problem. A dirty fuel filter is relatively inexpensive to replace, but incorrectly assuming other causes could lead to more costly repairs. Ignoring the problem can cause serious engine damage.
