How to Identify and Fix Common Engine Noises

Engine Related Issues

By Rodney (Mechanics)

Engine noises may be alarming and irritating, in particular when you do not know what they mean or the way to restore them. In this text, we are able to give an explanation for a number of the maximum not unusual engine noises, their reasons, and their answers. We can even provide you with a few suggestions on a way to save you engine noises and hold your engine’s fitness.


Squealing is a high-pitched noise that normally comes from the engine belt or the accessories it drives. The engine belt, additionally called the serpentine belt, is a rubber belt that connects the engine’s crankshaft to the alternator, water pump, energy steerage pump, air conditioning compressor, and different components. The belt can squeal while it’s far unfastened, worn, cracked, or glazed. This can affect the performance and efficiency of the engine add-ons and reason overheating, battery drain, or steerage troubles.

To fix a squealing engine belt, you need to inspect the belt for any signs of damage or wear. If the belt is in good condition, you may need to adjust the belt tension or replace the belt tensioner. If the belt is damaged, you need to replace it with a new one. You should also check the condition and alignment of the pulleys and the accessories. A faulty or misaligned pulley or accessory can cause the belt to slip or rub and create noise.

To prevent a squealing engine belt, you should regularly inspect and replace the belt according to the manufacturer’s recommendations. You should also avoid exposing the belt to oil, coolant, or other fluids that can damage the rubber. You can use a belt dressing spray to lubricate and protect the belt from squealing, but this is only a temporary solution.

Check a Serpentine Belt-How to Identify and Fix Common Engine Noises


Tapping or clicking is a rhythmic noise that commonly comes from the valve educate or the cylinder head. The valve train consists of the camshaft, the lifters, the pushrods, the rocker arms, and the valves. The valve teach controls the outlet and closing of the valves to allow air and gasoline to go into and exit the cylinders. The valve train could make a tapping or clicking noise when there is not sufficient oil strain, while the valve clearance is simply too large, or whilst the valve components are worn or broken.

If you hear a tapping or clicking sound from your engine, you want to check how lots oil you have got and the way nicely it flows. If you do not have enough oil, you need to fill up greater. If the oil isn’t always flowing properly, you may have a grimy oil filter out, a broken oil pump, or a hollow inside the oil pipe. You should also check the space between the valve and the rocker arm or the lifter. The valve is a part that opens and closes to allow air and gasoline inside and out of the engine. The rocker arm or the lifter is part that pushes the valve. If the distance is just too large, the valve will now not near all of the way and make noise. You can use a skinny metallic strip to degree the gap and comply with the instructions from the maker of your vehicle to adjust it. You should additionally study the valve parts for any signs of wear or damage. If the valve elements are worn or damaged, you want to get new ones.

Tapping-Clicking-How to Identify and Fix Common Engine Noises

To keep away from a tapping or clicking sound from your engine, you should exchange the oil and the oil clear out regularly consistent with the instructions from the maker of your vehicle. You must additionally use the right type and high-quality of oil for your engine. You have to additionally check and adjust the space between the valve and the rocker arm or the lifter once in a while, specifically if your engine does no longer have hydraulic lifters. Hydraulic lifters are components that regulate the gap routinely and do now not need guide adjustment.

Diagnose Tapping - How to Identify and Fix Common Engine Noises


Grinding is a harsh noise that typically comes from the bearings or the crankshaft. The bearings are steel jewelry that support and reduce friction among the rotating components of the engine, together with the crankshaft, the connecting rods, and the camshaft. The crankshaft is a metallic shaft that converts the up and down motion of the pistons into rotational motion. The crankshaft could make a grinding noise whilst the bearings are worn or broken, while the crankshaft is bent or cracked, or while the oil level or strain is low.

To replace the grinding shaft or bearings, it is always necessary to check the oil level and pressure. If engine oil level is low, you have to add some more oil in your engine. If low oil pressure is the condition you have, then it is either that your filter is clogged or oil pump is faulty, or you have leaks in the oil system. Here you should view the wear and damage signs of the crankshaft and the bearings. The use of a micrometer for obtaining the diameter of the crankshaft and comparing it with the manufacturer’s specifications is an option. Furthermore, you can put also a plastigage in the gap between the crankshaft and the bearings to measure the clearance. When the crankshaft or bearings are old and damaged, you have to replace them with new ones. In order to machine or replace the engine block and cylinder head, you may machine them if they are damaged.

To prevent a grinding crankshaft or bearings, you should regularly change the oil and the oil filter according to the manufacturer’s recommendations. You should also use the correct oil viscosity and quality for your engine. You should also avoid overloading or overheating the engine, as this can cause excessive stress and wear on the crankshaft and the bearings.

Grinding-How to Identify and Fix Common Engine Noises


A combustion popping is the sharp sound that commonly comes from a combustion chamber or an exhaust system. The area where air and fuel mix together is ignited by the spark plug in the combustion chamber to generate power. The exhaust system is used to pass gases which are emitted from the engine towards the tailpipe. Popping noise may be as a result of lean mixture, ignition system malfunctions, blocked fuel filter, dirty or oily spark plug, broken spark plug cable or damaged catalytic converter.

To eliminate a popping noise, testing of the air-fuel mixture and the ignition device should be done. The air-fuel mixture is the ratio of air and fuel that enter the combustion chamber. The air-fuel combining should be balanced and steady for the best performance and effectiveness. If the air-gasoline mixture is too lean, then there may be more air than gasoline; the combustion will be incomplete and therefore cause popping. Use a test meter to obtain the oxygen sensor records and the fuel trim values and determine if the air-fuel mixture is lean. A vacuum gauge can also be used to check the intake manifold vacuum. In the event of a lean air-gas mixture, you may be having a vacuum leak, clogged gas injector, faulty gas pump or a dirty air filter.

Also verify the ignition system components such as spark plug, spark plug wires, rotor, distributor cap and ignition coil. The ignition system is the system that is responsible for causing and delivering the spark to the spark plugs at the right time. If the ignition system fails, the spark will either be weak or uneven and again result in the popping sound. Timing light and spark tester can be used to test the spark quality and ignition timing respectively If ignition system is not in good condition, you may be having a worn and/or damaged spark plug, a cracked and/ or corroded spark plug wire, a dirty and/ or loose distributor cap or a worn and/ or a broken rotor or a defective ignition coil.

To eliminate the popping noise, you should routinely check and swap the air filter, the fuel filter and the spark plugs and their wires as per the manufacturer’s recommendations. And the octane and quality of the fuel you use should also be correct for your engine. In order to avoid this, you must not use low-grade or contaminated fuel, as this will result to deposits or clogs in the fuel system and in the combustion chamber.


The loudest noise come from the pistons or the connecting rods and it often the case when it is knocking. The piston is a cylinder of metal that travel up and down inside the cylinder bore and compress and expand the air and fuel mixture. This connecting rods are metal rods that unite the pistons and the crankshaft. You can hear that noise because of the incorrect ignition timing, low octane fuel, a bad knock sensor, worn out or damaged piston, a bent or broken connecting rod, or low oil level or pressure.

The diagnosis of a knocking noise must involve checking the ignition timing, the fuel octane, the knock sensor, oil level and pressure, the state of the pistons and the connecting rods.

Ignition timing is when the spark happens that makes the gas and air burn in the engine. The spark must happen at the right time with the engine speed and the piston movement. What results if the ignition occurs too early, is that the combustion occurs before the piston reaches the top and you start hearing a knocking noise. The scan tool can be a major instrument in reading all of the engine codes and the timing light can be applied in checking and adjusting the ignition timing.

The octane of the fuel is the number that represents the resistance of the fuel to the knocking. Fuel octane required for the engine to burn should be same as the compression ratio and operating conditions. In case the octane level of the fuel is too low ( the fuel will ignite very easily), the combustion will be too fast and as a result, a knocking noise is created. You can employ a fuel octane tester to seek the fuel octane and if the necessity arises, use a higher octane fuel.

The knock sensor is a sensor that listens to the knocking noise and send the information to the engine management computer in order to retard the ignition timing. The knock sensor needs to be operational, mounted securely, and in a good state. If the knock sensor not functioning properly, the engine computer will not be able to adjust the ignition timing in order to avoid the knocking sound. You needle a multimeter to check a knock sensor resistance and voltage and swap the knock sensor if it is distorted.

To lubricate and cool the pistons and the rods, the oil level is very important in the pressure. If oil is low, you have to add some oil to oil. Oil pressures that are low can be caused by a clogged oil filter, a damaged oil pump or a leakage in the oil system.

In addition, you need to take a closer look at the condition of pistons and the rods for any sign of wear and damage. Using a bore gauge to measure the diameter of the cylinder oil and compare it with the specified diameter manufacturers is ideal. Also, make use of a plastigage to determine the clearance between the piston and cylinder wall and, between the connecting rod and crankshaft. When the pistons or the connecting rods get damaged or worn out, new replacements must be provided. Moreover, after seizing up the bearings, you will need to machine or replace the engine block or the cylinder head if they got damaged.

To avoid engine knocking you should regularly execute an oil and oil filter replacement in accordance with the manufacturer’s instructions. In addition, you need also to choose the right oil viscosity and grade for your engine. Another thing that you need to steer clear of is using cheap or contaminated fuels, as this leads in pre-ignition and detonation in the combustion chamber.

How to Identify and Fix Common Engine Noises

How to Diagnose Engine Noises

To find the cause of engine noise, you need to apply the right tools and methods.

  • A stethoscope: Stethoscope is a tool that makes the sound louder and enables you to listen to the engine’s different parts. With the aid of a stethoscope you can determine the exact position of the noise and whether it is from the belt, the valve train, the crankshaft, the pistons, or the exhaust system. Remember to keep the stethoscope a safe distance away from the rotating or hot parts of the engine.
  • A code reader: The code reader is a unit that reads the engine codes and shows them on a screen. You may use a code reader to examine if the engine computer contains any trouble codes that indicate a problem with the engine or any of its components. You can also employ the code reader to erase the codes as you correct the problem.
  • A scan tool: A scan tool is a device use to read and show digital engine data and sensor values. Also you can use the scan tool to observe the engine performance and the performance of the engine systems. You can also do performance tests and adjustments on the engine sub-components using a scan tool.
  • A vacuum gauge: A vacuum gauge is an instrument that checks the vacuum of the inlet manifold. Check the engine and air-fuel mixture using a vacuum gauge can be done by you. A very low or fluctuating vacuum value can indicate a vacuum leak, a lean air-fuel mixture, a valve problem, or a compression problem.
  • A compression tester: A compression tester is an equipment that meters the cylinder compression. The compression tester will let you inspect the condition of the pistons, the rings, the valves and the head gasket. A low or unsteady compression value can is an indication of a worn or damaged piston, a broken ring, a burnt or bent valve, or a blown head gasket.
  • A leak-down tester: A leak-down tester is a device that indicating the amount of air that leaks from the cylinder. With a leak-down tester it is possible to diagnose the status of the pistons, the rings, the valves, and the head gasket. A high or fluctuating leak-down reading can imply a worn, damaged or broken piston, a broken ring, a burnt or bent valve or a destroyed head gasket.

How to Prevent Engine Noises

The problem of engine noises could be addressed by the proper engine maintenance and adherence to manufacturer’s recommendations. here the tips:

  • Change the oil and the oil filter often.
    The oil and the oil filter cannot be removed because they are needed to lubricate and cool the engine and all of its components. You can change the oil and the oil filter either at the recommended time by the manufacturer or much more frequently if you drive under severe conditions. Make sure that you check the viscosity and quality oil for your engine too.
  • Replace air filter with the regular basis.
    The air filter is the key part for the air filtering process of the air entering the engine and the combustion chamber. You have to change the air filter following the recommendations of the manufacturer, or more often if you drive a lot in dusty or polluted areas. You should also be sure to put air filters of the correct size and type for your engine.
  • Replace fuel filter more often.
    The fuel filter is so important for cleaning the fuel that enters both the engine and the combustion chamber. It should be the case that you should change the fuel filter in accordance with the manufacturer’s recommendations or more often if you use low quality or contaminated fuel. In addition, you should use the correct size and type of the fuel filter for the engine.
  • Frequently replace the spark plugs and the spark plug wires.
    Spark plugs and spark plug wires play crucial roles of igniting and transferring sparks to the spark plugs at the exact time. Check the spark plugs and spark plug wires every time of the manufacturer’s advices or more often if you see the decrease of the fuel economy, poor performance, or engine misfires. In addition you should use the optimal spark gap and type of spark plugs for your engine.
  • Check your valve clearance periodically and adjust it accordingly.
    Clearance is a gap between valve stem and the drawing liner or the lifter. Should be the true with the specifications of the manufacturer of the valve clearance for the best performance and efficiency. When the gap of the valve is excessively large or too small, the valve won’t open and close as it should and keep making noise. It is worth noting that you need to check and reset the valve clearance either periodically or often, and this requirement is particularly necessary if the engine has a mechanical valve train that does not have hydraulic lifters. Hydraulic lifters are self-adjusting and, therefore, valve clearance adjustment is not needed.
  • Replace the head gasket on the engine and reset the timing every two to three years.
    The engine belt and the belt tensioner are key components for powering the engine accessories, example, the alternator, the water pump, the power steering pump and the air conditioning compressor. Check and replace the engine belt and the belt tensioner periodically. The manufacturer’s recommendations or the earlier time if you find cracks, wear, or noise. Make sure that the cables, brake, and other accessories are in good health as well.
  • Use the right fuel octane and quality for your engine.
    The compression ratio, octane rating and quality of combustion are critical to stopping pre-ignition and knocking in the cylinder. Engines need the correct fuel octane for types and quality, recommended by the manufacturer or more often if you notice knocking or pinging or loss of power. You must also remember that you should not fill your car with low-quality or contaminated fuel cause carburetor and inlet valve clogging.
  • Do not overload nor overheat the engine.
    Excessive stress and wear of each component the engine and the engine itself may occur by an overloading or overheating. To prevent overloading the engine, overheating and damage to the engine components, you should follow the manufacturer’s guidelines on the maximum load and the speed at which the engine can run, you should use the correct gear and driving modes, you should check and refill the coolant level and the radiator cap, you should check and repair the cooling fan and the thermostat, and you should avoid driving in extreme weather or terrain conditions

Engine noises could be a symptom of an arising problem that can result in engine performance, efficiency, and security issues. Never do you ignore or neglect any engine noises, they can get worse ultimately and it leads to more damage and costs. Starts with the diagnosis and repair of engine noises immediately, applying the correct tools and techniques. Besides that, you have to make sure that engine noise does not occur by ensuring that your engine is serviced properly and consulting the manufacturer’s recommendations.