We here at Clark’s Car Care do not recommend that you drive your automobile if the engine is knocking. The reason why is that one cause of engine knock can severely damage your cylinder block. Repairing this damage requires a partial engine rebuild. As such, it’s important that you have your vehicle towed to our shop right away if the engine is knocking. Here are the things that will make an engine knock.
A Fuel Mixture Heavy in Air
Poor detonation is the most common cause of a knocking engine. Driving your automobile with detonation knock will not necessarily damage the engine but will affect the engine’s performance. One thing that can cause the engine to detonate poorly is a lean fuel mixture. This is a mixture that has too much air in it and is starved of fuel. Clogged fuel injectors are one thing that can create a lean fuel mix.
A Malfunctioning Knock Sensor
Another cause of detonation knock is a malfunctioning knock sensor. This sensor is manufactured and installed in your engine so it can detect when the engine is knocking. It sends an error code to the engine control unit (ECU) so it can correct things that cause engine knocking such as a lean fuel mixture. A faulty knock sensor will fail to detect the knock and send an error code to the ECU.
Incorrect Octane in the Tank
Your engine may also be knocking if you have the wrong fuel in the tank. Specifically, your owner’s manual will specify the recommended octane rating for the gasoline you should use. If you use a lower octane rating than what is recommended, the engine will knock because the fuel will fire multiple times in the cylinders. This, too, is detonation knock that can affect your engine’s performance.
Spark Plug or ECU Problems
In today’s automobiles, the spark plugs are fired by the ECU. If there is a problem with the spark plugs or the ECU, your engine may make a knocking sound because the plugs are misfiring in the combustion chamber. This can be caused by worn spark plugs or by an ECU that is firing them incorrectly.
Rod Bearings That Have Worn
As we mentioned in the introduction to this blog post, one cause of engine knock can severely damage the engine. This cause is worn rod bearings. These bearings move the rods that move the pistons up and down inside the cylinders. If the bearings are worn, the rods will vibrate and cause the pistons to make damaging contact with the inside of the cylinders.
Call Clark’s Car Care in Naperville, IL, today to schedule an appointment so we can inspect your engine to determine why it is knocking. We will find the problem and fix it.