engine noises

Diagnosing Common Engine Noises: Why you shouldn’t Ignore any

Every car has its unique set of noises. As the driver, you become accustomed to these noises and recognize that they do not indicate a problem. However, if those noises begin to change, it is more likely that something is wrong with the way your car runs. While it could be something absolutely simple, if the noises are coming from your engine, you should have them checked.engine noises

In this article, we’ll go through the most common types of car engine noise you may hear if something is wrong with the engine, the reasons why you shouldn’t ignore them, and what you should do.

So, let’s get to it!


Types of engine noise you may hear

Here are the most common engine noises you might begin to hear when there’s an issue with your car:

Timing Chain Engine Noise

Many contemporary engines include overhead camshafts and longer timing chains. To guarantee that the valves open at the correct moment, a timing chain connects the crankshaft to the camshaft. Hydraulic tensioners normally keep the slack in these chains tight. The chains ride against a nylon guide (a chain guide) that wears out over time.

The timing chain begins to rattle as the chain guides wear beyond the ability of the hydraulic tensioner to take up the slack. The timing chains have become so slack that they are whipping back and forth against the guides and potentially the timing cover, causing this noise. If the oil pressure is correct, replacing the hydraulic tensioners and chain guides is required.

A mechanic’s stethoscope is an excellent instrument for locating this noise. If the noise is loudest when touching the timing cover with the stethoscope, disassembly is required to confirm and rectify the problem. For most of these engines, this is a semi-major job that would normally cost in the four-digit range.

Valve Train Engine Noise

The clicking sound of the valve and hydraulic lifter noise normally subsides as engine RPMs increase. A lifter is responsible for opening and closing intake and exhaust valves. Hydraulic lifters that have worn or get stuck can generate these noises. The most common reason for sticking lifters is a varnish buildup on the lifter surfaces.

Low oil pressure (which would cause a hydraulic lifter to collapse) could be the cause. Adding a detergent addition to the oil will often help with sticking lifter problems. If this does not eliminate the issue, the worn lifters that continue to generate noise will need to be replaced. This is not a simple or inexpensive job that should be performed by a professional vehicle repair technician.

Connecting Rod Engine Noise

Excessive space between the crankshaft and the connecting rod bearing surface causes connecting rod noise. This occurs when there is insufficient oil pressure, causing the bearing to run dry of lubrication, causing damage to the bearing and crankshaft surfaces. Poor maintenance practices, such as not changing oil at regular intervals, can also contribute to this.

Grit can damage the surface of the bearings as the oil becomes unclean. The noise you’re hearing is a knock near the bottom of the engine. When you maintain the throttle at a constant RPM, you will usually hear the noise. If it sounds like a single knock, you (or your mechanic) can isolate the cylinder by turning off the spark or fuel injector for each cylinder individually.

When the noise stops or becomes substantially quieter, you’ve located the source of the problem. Such issues demand prompt repair because continuing to run the engine in this state may destroy the crankshaft and necessitate a significant engine overhaul. The general guideline is that once you hear the noise, there is a good chance you’ll need serious engine maintenance in the four-figure bracket.

Detonation, Pre-Ignition (Pinging) Engine Noise

When you accelerate your vehicle, you will frequently hear this noise. Most people refer to this as a pinging or rattling sound. The heat of compression causes an air/fuel mixture in the engine cylinder to ignite prematurely as the piston moves up on the compression stroke, causing this noise. Pre-ignition or pre-detonation occurs when ignition occurs before the piston reaches the top of its stroke, and it can damage the pistons, valves, and connecting rods.

They are damaged as a result of the fuel igniting too early, which causes pressure waves from the fuel’s explosion in the cylinder to clash with the cylinder as it moves up. That’s also why you’re hearing pinging and rattling sounds. Improper fuel octane, engine overheating, incorrect ignition timing, the EGR valve not functioning properly, and computer or knock sensor difficulties are some of the reasons for this condition.

All of these factors can cause the air-fuel mixture in the cylinders to ignite sooner than expected. This results in several flame fronts fighting each other in the cylinder, generating a pinging and rattling noise. Make sure you’re using the correct gasoline grade by consulting your owner’s manual. You might also try switching to a higher grade for a while to see if the noise goes away. If it doesn’t, you should look into these other possibilities.

Whining Engine Noise

When an engine is operating, a whining noise usually indicates that a bearing is about to fail. As the engine RPMs rise, so will the noise. However, keep in mind that bearings are employed in a variety of places throughout the engine. As a result, various components under the hood can produce this type of whining sound.

The water pump, air conditioner clutch bearing (heard only when the compressor is not engaged), fan belt idler pulleys or belt tensioner, alternator, and power steering pump are all potential causes of whining sounds suggesting impending bearing failure.

When rotating the steering wheel from side to side, the power steering pump’s whining becomes louder, and the main cause is low power steering fluid. The best technique to diagnose the other bearing noises is with a mechanic’s stethoscope. Failure to repair any of the items that are creating a whining sound can lead to vehicle failure.

Piston Slap

This noise is typically seen in high-mileage vehicles and is caused by excessive space between the piston skirt and the cylinder wall. The most common cause of this issue is cracking in the lower piston skirt. The piston skirt is the lower section of the piston that will develop cracks due to metal fatigue over time. The noise is more evident when the engine is cold and sounds like a muted bell sound or a hollow clatter deep inside the engine.

If the noise goes away after the engine heats up, no action is required. The expansion of the piston skirt when the engine warms up reduces the clearance, and in many cases, the noise disappears completely. If the noise decreases as the engine temperature rises but does not disappear, replacing the piston is the most likely solution. There is nothing you can do to prevent this problem, and fortunately, it is not as serious a repair task as some of the ones mentioned above.

Crankshaft Bearing Engine Noise

Low oil pressure also causes crankshaft bearing noise, as it affects the bearing surfaces and may eventually destroy the crankshaft itself. When accelerating, this type of noise is typically described as a rumbling or thumping sound deep within the engine.

If this sound is heard, the engine should not be started again until the oil pan is removed and the crankshaft bearings are inspected. If the crankshaft is not destroyed, the engine can often be saved. A mechanic will resolve the issue by changing the bearings and resolving the oil pressure issue.

The crankshaft revolves within bearing shells. You will almost probably cause a serious engine failure if you continue to operate the engine in this condition. It is also possible that by the time you notice the noise, it will be too late to save it without removing the engine. This can be a costly repair in the four-figure range.

Piston Pin Engine Noise

Valve train noise is similar to piston pin noise. The noise is distinct due to the absence of oil and significant clearance between the piston pin and the piston. A piston pin connects the connecting rod to the piston. It is lubricated by oil sprayed onto the pin through a hole in the connecting rod of the opposing cylinder.

This condition can only be corrected by replacing the piston pin bushings, and maybe the piston itself, as well as addressing the oil pressure or lubrication issue. Problems like this are frequently the result of worn connecting rods and crankshaft bearings, which limit oil pressure. If you have this issue, it will necessitate extensive engine work in the four-figure area.

Why you shouldn’t ignore any of this noiseengine noises

As a responsible vehicle owner, you must not ignore any of the engine noises that have been identified and discussed. Each noise is a crucial indicator of potential problems with your vehicle. Ignoring these sounds can have significant consequences for your safety, pocketbook, and driving experience overall. Here are some of the reasons why you should pay attention to each engine noise:

Safety First

Engine noises can be early indicators of potential problems within your vehicle. Ignoring strange sounds may lead to more serious problems in the future, risking your driving safety. By paying attention to these noises, you can solve issues quickly and avoid accidents or breakdowns.

Cost Savings

Ignoring engine noises may result in more serious damage, resulting in higher repair expenses. Early detection and resolution of problems might save you from costly repairs or even engine replacement.

Preserving the Life of Your Vehicle

Regular maintenance and swiftly addressing engine noises can dramatically increase the life of your vehicle. By addressing minor concerns early on, you can avoid significant breakdowns and keep your automobile running smoothly for longer.

Avoiding Unexpected Breakdowns

There is never a good time for your car to break down. You can lessen the likelihood of being stranded on the road due to an unplanned breakdown by paying attention to engine noises and swiftly dealing with any problems.

Improved Fuel Efficiency

Some engine noises may be the result of inefficient combustion or fuel-related difficulties. Taking care of these issues can increase your vehicle’s fuel efficiency, saving you money at the pump and lowering your environmental effect.

Protecting Your Investment

Your vehicle represents a substantial financial investment. Ignoring engine noises may reduce its resale value or make it more difficult to sell in the future. Regular maintenance and timely resolution of issues will help to preserve the value of your investment.

Peace of Mind

By being proactive and sensitive to engine noises, you may drive with better peace of mind, knowing that you are properly maintaining your vehicle and protecting your and your passengers’ safety.

What should you do when you begin hearing engine noise?

When you first notice engine noise:

  • Stop driving right away.
  • Determine the nature and location of the noise.
  • Check the engine oil level.
  • Examine the vehicle for visible damage, loose belts, or leaks.
  • Avoid driving the vehicle if unsure or if the noise is severe.
  • Bring your vehicle to a skilled mechanic for an inspection and repairs.

Related Article

Watch the video below to learn more


Why is my car engine making noises?

This could be due to a low oil level or the need for an oil change, or it could suggest more significant mechanical concerns, such as the need to replace the oil pump. If your engine makes a pinging or banging noise, you may be suffering incorrect combustion.

What engine noises are normal?

Most engines will sound like jets and will be louder when revved. Humming or clicking noises are also possible. Do not be scared. All of this is very normal.

What is abnormal engine noise?

Like a continuous muted, hollow sound. Excessive piston-to-wall clearance, damaged cylinders, or insufficient lubrication are common causes. A persistent piston slap sound indicates that the engine needs service. Still, if the sound is only audible when the engine is cold, it is most likely not a significant problem.

Why does my engine make a loud sound when accelerating?

A car’s engine has many moving parts, and a loud noise when accelerating could signal engine difficulties. For example, worn valves might generate a clicking noise that becomes more obvious as the car speeds up. Bearings, which let the camshaft and crankshaft spin, can also be noisy when they fail.

What does tappet noise sound like?

A ticking, tapping, or clicking sound from the top of the engine is usually indicative of a problem with the tappets.

What is engine bearing noise?

The noise from your bearing could be whistling, rattling, or snarling. Unfortunately, if you hear this noise, your bearing has failed, and the only cure is to replace it as soon as possible. Adding lubricant to your bearing may help to reduce noise.

What do bad valves sound like?

At half engine speed, valve and tappet noise normally starts as a clicking sound, or chatter, and disappears at high speeds. Excessive valve clearance or a faulty hydraulic valve lifter is frequently to blame.

And that is all for this article, in which we looked at the most common types of car engine noise you may hear if something is wrong in the engine, reasons why you shouldn’t ignore them, and what you should do. Hope you learn a lot from the reading. If you do, kindly share it with others. Thanks for reading; see you around!


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