If your vehicle manufacturer recommends high-octane gas for your automobile, then, yes, you do need to put high-octane gas in the tank. If you put a lower octane rating than what is recommended, your engine will knock constantly. Fuel with higher octane fires up faster in the cylinders. Fuel with lower octane will not fire as quickly and, as a consequence, you will have multiple firings in the cylinders. Oxford Automotive explains that this is the knocking you are hearing. This is just one thing that will make your engine knock. Here is a list of the other things.
Bad Spark Plug Timing
The spark plugs are designed to fire in a specific order. If they fail to fire in this order, your engine will misfire. This misfiring is bad engine timing. The misfiring also causes multiple detonations in the cylinders just like low-octane gasoline does. This is why bad spark plug timing can make your engine knock. The problem may be worn spark plugs or an issue with your vehicle’s main computer chip. In newer automobiles, the computer chip fires the spark plugs in a specific order.
Lean Fuel Mixture
A lean fuel mixture will also cause multiple detonations in the cylinders. This is because there is more air than fuel in the mixture. This, too, will make your engine knock. If you have a fuel delivery problem or a clogged fuel filter, this can make the fuel mixture in the combustion chamber too lean. Other issues that affect the fuel mixture include vacuum leaks and faulty mass airflow or oxygen sensors.
Faulty Knock Sensor
Speaking of faulty sensors, your automobile’s engine is equipped with a knock sensor to detect any time the engine knocks. When the engine knocks, the sensor reports the problem to the main computer chip so it can make adjustments to stop the knocking. Naturally, if this sensor is going bad, it may not send an error report to the main computer chip. Consequently, your engine will knock.
Loose Rod Bearings
Finally, another cause of engine knocking is loose rod bearings. The rod bearings move the rods up and down so the rods can move the pistons in the same manner. If the rod bearings are loose or worn, the rods will not go up and down smoothly. Consequently, the knocking that you hear is the pistons banging against the cylinder walls.
Oxford Automotive in Oxford, PA, would be happy to get to the bottom of your engine knock. Call us today to set up an appointment.