The most common symptoms of a faulty knock sensor are engine noises, flashing dashboard or “Check engine” lights and diminished fuel economy. These symptoms are most common when the vehicle is travelling at highway speeds or carrying a heavy load. To properly assess the condition of the knock sensor, compare engine performance to its factory specifications found in the vehicle’s manual.Continue Reading
Flashing or activated warning lights are the most common indication of a bad knock sensor. A faulty knock sensor pairs activated or flashing warning lights with strange engine noises, which are the most common symptoms associated with faulty knock sensors.
Common engine noises associated with faulty knock sensors include sputtering, knocking and pounding sounds. These noises stem from pre-ignition, which results from fuel and air igniting inside the cylinders instead of burning evenly throughout the engine.
Faulty knock sensors also decrease fuel economy. Fuel efficiency decreases with faulty knock sensors because of an improper mixture of fuel and air. The engine cannot combust properly, which leads to higher emissions and reduced fuel economy.
A faulty knock sensor miscalculates the fuel to air ratio. When this ratio is not properly determined, the vehicle cannot accelerate nor use fuel efficiently. Faulty knock sensors disrupt communication between the engine and the vehicle’s computer. This disruption diminishes vehicle performance through a misallocation of fuel delivered to the engine.Learn more about Car Parts & Maintenance
Symptoms of a dirty fuel filter include losing power while driving uphill, problems starting the car, stalling, grinding noises in the engine, the smell of gas fumes and an engine that misfires frequently. An engine that hesitates when the accelerator is depressed can also indicate a dirty fuel filter, especially when this occurs at slow speeds.Full Answer >
The typical signs of a faulty oxygen sensor include increased exhaust emissions due to poor air fuel mixture, engine hesitations, engine misfires, stalling, rough idling and increased fuel consumption. The oxygen sensor is a crucial component of a vehicle's electronic fuel injection and emission system, and it relays information to an on-board engine management computer that regulates fuel delivery to the engine.Full Answer >
A bad mass air flow sensor in a vehicle makes starting difficult and affects the performance of the engine because he engine-control unit uses data from the MAF sensor to balance the fuel ratio the injectors deliver to the engine. A bad sensor returns a significantly different temperature than that of the engine coolant when read using a scan tool set to temperature.Full Answer >
Problems with acceleration, engine misfires, reduced fuel mileage, stalling and difficulties starting the vehicle are all possible symptoms of a bad crankshaft sensor, according to 1A Auto. A bad crankshaft sensor may also cause the vehicle to idle roughly or make the check engine light come on.Full Answer >