(866) 924-4608

We Buy All Cars, Running or Not!

(866) 924-4608 FAST CASH OFFER
What are the Causes and Symptoms of Engine Tapping? What You Need to Know!

What are the Causes and Symptoms of Engine Tapping? What You Need to Know!

When you start your engine, you will usually hear its distinctive sound, its sweet purr that goes louder when you rev your engine. If you hear an unusual sound that seems coming under your car’s hood, it can be an indication that there is something wrong. If there is a problem, you may hear grinding, squealing, clicking, or tapping noises. It can be alarming if you don’t know what it means. If you hear a tapping sound from your engine, you might ask, “what are the causes and symptoms of engine tapping?”. Engine tapping is caused by problems with the tappets or valve lifter, rocker arms, bearings, exhaust manifold, spark plugs, or issues with the lubrication.

Auto Repairs Are EXPENSIVE


Aside from the tapping noises, symptoms of engine tapping include reduced power, decreased engine efficiency, poor fuel economy, engine overheating, and premature wear of the engine and its components. Failing to correct the problem may lead to expensive repair bills due to severe engine damage. That is why when you notice any of the symptoms of engine tapping, you need to act on it immediately. In this article, we will discuss everything about this problem and what you need to know!

Symptoms of Engine Tapping: Why is My Engine Making a Tapping Sound?


It is said that there are car engines that have a normal tapping noise which are produced by the car’s electrical components such as relays, solenoid, and injectors. The engine itself can also produce this tapping sound since it is turning thousands of revolutions per minute or RPM. However, engines in general should only have a very soft tapping noise. Anything that sounds unusual should be addressed immediately since it means that there is a problem somewhere.


If you are asking, “what are the symptoms of engine tapping?”, it is most likely that you have noticed this problem in your car. Tapping sounds accompanied by reduced engine efficiency, power, and fuel economy can be some of the symptoms of engine tapping. When this happens, you might want to know why your engine is making a tapping sound.


You may notice engine tapping when your car has some issues with the following:


  • Engine tappets


Engine tappets are commonly referred to as the valve lifters or cam follower. It is a component of an internal combustion engine which is responsible for converting the rotation of the camshaft into vertical motion that opens and closes the intake or exhaust valve. It is a small cylindrical device that is attached to the pushrod’s end or the rocker arm. Its other end interacts with crankshaft lobes which start the motions of the valve to open and close when the cam profile rotates around its axis.


When you hear a tapping noise from your engine on start up, it might be caused by malfunctioning engine tappets. The tapping sound may disappear immediately right after the start up. This problem can happen when the engine oil becomes contaminated and dirty. When the oil has accumulated dirt and its viscosity is increased, the interaction between the engine tappets and the camshaft will start to wear down. This could result in the tappets and camshaft to produce tapping sounds as the camshaft spins and the lobes pick up and drop the tappets.


Aside from the annoying tapping sounds, this problem can also cause other symptoms of engine tapping such as reduced power and engine efficiency. This can happen since a camshaft or engine tappet that has worn down can lead to a valve not opening to its pre-programmed lift distance. This can limit or restrict the air and fuel mixture as it tries to rush into the cylinders.


When you notice this problem, you will have to address it immediately, failing to do so may further damage the engine and its components due to insufficient lubrication. If this happens, the problem will become very expensive to fix.


How do you fix it?


To start, you will have to check your oil’s viscosity. If it is due for a replacement, you have to have it replaced immediately to get rid of the engine tapping noise. This problem can also happen if you used the wrong oil in your car. If you use the wrong oil, the lubrication of your car’s many moving parts within the valvetrain will be adjusted from conditions which these components are made for.


That is why it is important that during oil changes, you should follow and use the recommended type of oil, with the right weight or viscosity, set by your car manufacturer. To know any specific details or instructions regarding what oil you should use on your car, you can consult your owner’s manual. If you use an oil that is less or more viscous than the recommended one on your car, it might result in insufficient lubrication.


As mentioned earlier, having your oil changed can help get rid of the engine tapping noises. You can also use an oil additive to clean your car’s rockers, valves, and tappets. If after the oil changes you still hear the tapping noise, you will have to fully adjust your tappet.


To do this, you need to use a feeler gauge to jam between the valve stem and a rocker arm. Consult your owner’s manual to know the factory setting and adjust the valve adjustment screw to the appropriate clearance. However, if after all the efforts and work you made and there is still an engine tapping sound, then better prepare a budget for the repair bill since replacing a tappet, camshaft, or valve can be costly.


  • Exhaust manifold leak


If you hear an engine tapping or ticking sound when you are accelerating or when at idle, it can be caused by an exhaust manifold leak. This can occur when the exhaust gases leak at high pressure due to a gasket leak or a manifold rupture. If you are driving while this happens, you can still continue driving since it is not considered a serious problem. However, you need to have it repaired as soon as possible since excessive exhaust gas leaks can cause damage to your engine.


How do you fix it?


You can start by doing a visual inspection of your car’s exhaust system. Look for any signs of leaks, cracks, or damage on the exhaust manifolds including the gaskets and bolts. If you notice black soot marks where the manifold is joined to the cylinder head, then it is an indication that there is indeed a manifold gasket leak. You need to take your car to an auto repair shop immediately and have it repaired.


  • Worn bearings


A rod knock can also be one of the causes and symptoms of engine tapping. When this happens, you will hear a deep tapping sound from the engine and it is caused by worn or damaged bearings. When worn, loose, or damaged rod bearings are the ones causing the tapping noise, then it means that your bearings will completely fail soon. It can either cause your engine to seize and lock up, or it will try to seize and break a rod. Either of the two can result in severe engine damage that can only be fixed with an engine replacement.


Although bearing issues and noises usually happen in engines with high mileage, it can still happen in newer cars if they are not maintained properly. If you have been neglecting your car’s oil and oil filter changes, then this will most likely happen to your car.


How do you fix it?


You need to inspect your bearings and look for any signs of wear or damage. To do this, you will have to drop the oil pan and check the rod and main bearings. If you notice that they are badly worn, loose, or damaged, you can have them replaced but it may only be a temporary fix.


A more permanent solution to fix the problem if your bearings are already severely worn or damaged is to have your crankshaft resurfaced. This means that a complete engine overhaul or replacement will be needed. If this is the case, it might not be worth it to go through all the trouble and expenses to have it repaired, especially if you own an older car and its market value is less than the total repair bill. It is much better to sell your car as is and move on.


  • Faulty belt tensioners or pulleys


A tapping or knocking sound can also be caused by a faulty accessory belt. This can happen since the belt which is connected to different pulleys throughout the engine bay turns when the engine runs. In order for the belt to turn properly and quietly, it should be under a precise amount of tension. If this belt becomes faulty or is stretched out, the tensioner won’t be able to work properly and will create slapping, knocking, or tapping noises. This problem can also happen when one of the pulleys is bent out of shape.


How do you fix it?


Getting rid of the tapping noises due to a faulty accessory belt can be easily fixed. You will just have to replace the faulty belt with a new one and adjust the tension, replacing the tensioner or accessory pulley if needed.


  • Low engine oil level


Low engine oil level can be the reason why you hear tapping noises which usually happen when your car is idling or when you are accelerating. When this happens, it means that the valvetrain components are not getting a sufficient amount of lubrication, causing them to start producing tapping noises.


How do you fix it?


The moment you hear any unusual sounds coming from your engine, you need to pull over and check what caused it. You need to check your car’s engine oil level immediately. To do this, locate your oil dipstick in the engine bay and check if the oil level is low.


If you don’t know how to read an oil dipstick, you just need to find the maximum fill level and the minimum fill level in the dipstick. You will usually find the letters “H”  for high or “L” for low or two dots. When you notice that the oil level is below minimum, you need to top it off. However, you also need to know what caused your oil level to become low. You can check for any leaks, or better yet, take your car to an auto service shop and have it checked.


  • Faulty spark plugs


Spark plugs that are cracked or loose can be one of the causes and symptoms of engine tapping. This can happen since spark plugs should be threaded properly into the heads of an internal combustion engine. If for some reason the spark plug is not fully seated to the head, maybe because of improper installation or cracks that prevent it from being fully tightened, it can lead to a bypass of combustion and exhaust gases which can cause a loud tapping noise.


How do you fix it?


You will have to visually inspect your spark plug. But before doing so, you need to make sure that your engine has been turned off and has cooled down. Inspect your spark plug and look for any signs of cracks or damage. If it is already damaged, you will have to replace it.


If there is no damage, you need to make sure it is not loose by wiggling it. If it moves, then it means that it is loose. Tighten it but make sure you apply the right torque. Applying the wrong torque can also cause some issues. You can check your owner’s manual to determine the right torque.



Aside from the annoying tapping noises, symptoms of engine tapping also include reduced power and engine efficiency. It is for this reason why you need to have your car checked immediately when you notice the tapping noises. You should make sure that your car’s engine is always running efficiently and at its best performance.