Some people believe that an engine knocking sound is a sign of death, and it can be depending on the reason why the engine is knocking. York Tire & Auto Service can find out why your car, truck, or C/SUV’s engine is knocking and fix it. Bring your vehicle into our shop at the first sound to avoid engine damage; it could be an engine block problem. Here are five things that make an automobile engine knock.
1. Bad Gasoline
Hopefully, the only reason your vehicle’s engine is knocking is because you put bad gas in it. This can still cause some damage, but oftentimes, an engine will knock if the gasoline’s octane is not high enough. Double-check your owner’s manual to make sure you’re putting the right octane in your vehicle at each fill-up. The lower the octane the greater the chances of engine knock.
2. Bad Timing
Engine timing is controlled by a computer in newer cars. The computer tells each spark plug when to fire. If they do not fire in the proper sequence, you will hear an engine knock. This sound is being caused by too many cylinders firing at once, which happens because the spark plugs are not firing in the correct order. This can also happen in older cars if the plugs are worn or installed in the wrong order.
3. Bad Air/Fuel Mix
Air and fuel in the cylinders are what the spark plugs fire up, and if the mixture isn’t correct, your engine will knock. If the mixture has too much air and not enough gasoline in it, it will be lean, and you might end up with multiple detonations in the cylinders that knock just like they would if the engine’s timing was off. Mixtures will too much gas tend to flood the engine and cause it to sputter and stall.
4. Bad Knock Sensor
Because engine knocks can cause serious damage, your automobile has an engine knock sensor. Everything is computer-controlled in your automobile unless you drive a classic, and the engine knock sensor detects engine knocks. If the engine is knocking, even at inaudible levels, the knock sensor will tell the Engine Control Unit there’s a problem. A bad sensor can make the engine knock.
5. Bad Bearings
If you’ve ever had a broken rod, you know this engine knock is deadly. Your pistons are pushed up and down in your engine block by rods. The pistons must move up and down in the proper order to turn the crankshaft – make your car move – and avoid crashing into it. Over time, the rod bearings can wear down, and once they do, you’ll hear the pistons knocking against the crankshaft.
York Tire & Auto Service can help. Stop by our auto shop in Red Lion, PA, so we can find the reason why your engine is knocking.