Most Common Engine Problems – Everything You Need to Know

An engine is the most important part of the vehicle. You should always make sure that the engine is in good condition. Engine maintenance is one thing you should never compromise. Some common engine problems can cause severe damage if you do not take action immediately.

It is quite challenging to diagnose the fault of your engine. If you notice any signs that something is wrong with the engine, you need to check it. Some problems are not so serious, but if they are not checked at the right time could cause expensive repairs. Here, we shall study some of the most common engine problems and failures.

How Does the Engine Work?

An engine is a complex part of a vehicle that most people do not understand how it works. As a vehicle owner, it is important to have a basic idea about how it works. With this knowledge, it will be easy for you to know when there is a problem with an engine part and how to deal with it.  

The vehicle engine converts gas into energy that moves the car. The engine is comprised of different components which work together to ensure the vehicle is moving smoothly. Without the engine, your car will be useless.

engine problems symptoms

What are the signs of a bad engine?

When your engine begins to act up and it is no longer reliable, it’ll be challenging to say precisely where the fault is coming from. Understanding the signs of internal engine damage and how to diagnose engine problems will help the mechanic understand what’s wrong with the vehicle and rectify it on time.

Here are the top signs of engine damage you should watch out for.

The check engine light illuminates on the dashboard

Generally, the check engine light illuminates on the dashboard whenever there’s an issue with the engine. The case could be a minor or major engine problem. Always diagnose the vehicle or have your mechanic read the stored trouble codes to track and resolve the underlying issues.

The warning could appear on the dashboard due to several issues, such as;

  • Defective catalytic converter
  • Bad oxygen (O2) sensor
  • Lousy mass airflow (MAF) sensor
  • Damaged manifold absolute pressure (MAP) sensor
  • Loose or missing fuel cap
  • Random engine misfire
  • Worn or dead spark plugs
  • Damaged injectors
  • Other sensor and actuator-related issues.

You can perceive odors inside the cabin.

Every internal combustion engine-powered vehicles have exhaust fumes. But it should not come into the cabin. If you perceive engine fumes, exhaust smell, or any strange smell inside the cabin, something is wrong with the vehicle. It could be you have an engine problem. Do not ignore these signs and expect them to disappear. Contact a mechanic to track the leading cause and fix it.

Your vehicle is losing power

Cars should be able to turn into road beasts on the highways or, at least, run smoothly. If your vehicle starts losing power while driving, stalling, shaking, or misfiring, you have issues with the engine components. If you start experiencing any of these issues or the vehicle is no longer running as it used to, contact a service technician to diagnose and resolve the problem.

Your vehicle is consuming more gas

If your engine starts consuming more gas than usual, there are issues with the compression stroke. The most feasible solution is to service the fuel system. You can also run engine diagnostic tests to track why the car takes more gas than usual.

Your engine continues running even after the ignition is switched off

This usually happens when there is incorrect gas octane, which is common in high-performance vehicles. Other possible causes are over-active carburetor and lousy solenoids.

Your engine is misfiring or running rough

If you have driven your car for years, you’ll agree that engine misfiring or rough running is just a matter of time. It happens to all internal combustion engines at one point. If your engine runs rough, stutters, or misfires, it indicates that one or more engine components are not functioning as the manufacturers predefined it.

The leading causes could be that your engine needs a service tune-up, you have clogged filters, malfunctioning car sensors, worn spark plugs, a weak fuel pump, and other related engine issues.

Oil puddles under your vehicle

Another notable sign of a bad engine is oil puddles underneath the vehicle. Oil puddles underneath a vehicle typically mean an oil leak in the car. When oil leaks exist, the oil level will decrease over time, causing excessive friction on the reciprocating internal engine parts. This will further lead to severe engine damage.

Oil leaks are usually from dry or bristled seals, gaskets, and sump plugs.

Your engine is making strange noises

Car engines are supposed to make minimal noise. If the engine starts making a knocking or kicking noise, it shows something is wrong with the engine. Strange noise from the engine is one of the common signs of engine damage from low oil. It could mean the pistons, bearings, and other reciprocating engine parts are worn out, or oil is not lubricating them properly. This can be caused by a loose timing chain or timing tensioner, low engine oil, or a lousy oil pump.

Always contact your mechanic whenever you notice a strange noise from your engine. Ignoring the noise can lead to catastrophic engine breakdown. Of course, this will drop expensive repair bills on the table. Other engine noises you should watch out for include rattling, spitting, and popping noises.

Smoke is coming from the exhaust tailpipe

Several factors can cause your vehicle to emit smoke from the tailpipe. This makes it difficult to track the root cause. However, the color of the smoke can help you narrow down the root cause of the problem.

If the tailpipe emits black smoke, it signifies the engine is having incomplete combustion, which is causing it to consume more gas than usual. The possible causes of black smoke include

  • Mechanical damage in the engine
  • Lousy car sensors
  • Defective fuel injectors
  • Clogged fuel return line
  • Clogged or blocked air filter

If dark blue smoke is coming out of the tailpipe, it means the engine is burning oil. Here are the possible reasons for blue smoke from the exhaust

  • Damaged valve seals
  • Damaged piston rings
  • Other worn-out internal engine parts.

Grey smoke can be challenging to diagnose because it means several different things, such as;

  • Excessive engine oil consumption
  • Stuck PVC valve
  • Contaminated transmission fluid.

Common Engine Problems and How to fix them

Knowing how the engine works, it is important to know some of the issues you may face in your driving experience. Here are some common engine failures that most car owners face and how to diagnose engine problems:

1. The Engine Will Not Start

This is one of the worst car engine problems that vehicle owners face. There are various reasons why a vehicle can fail to start. 

One of the most common reasons is a battery-related problem. It could be that the battery is discharged or dead and need to jump-start. In case it is a problem with the battery, you will hear some clicking sound.

Another reason would be the vehicle is having a problem with the starter. The starter gets the engine moving, and therefore if it has a problem, it will not start. It could also be due to a clogged fuel filter. The combustion process will not initiate if there is a problem with the fuel pump or the fuel filter is obstructed.  

A vehicle will fail to start due to a broken ignition switch, battery cables, or failure in the catalytic converter. If the problem is the battery, get a jumper cable and try jump-starting the vehicle. If it is for another reason, then you need to visit a mechanic.

2. Worn Spark Plugs

This problem is most common in older vehicles. Although spark plugs are small, they are quite important for the effective performance of the engine. These engine parts are what make the vehicle move. Their work is to ignite the compressed gas within the engine.

A dirty or worn-out spark plug will create a weak spark or no spark at all. This causes engine misfire, stalling, hard starting, or Engine Start but won’t Stay Running. Always take some time to regularly check and ensure that the spark plugs are in good condition. You should also learn How to Tell if a Spark Plug is Bad.

3. Clogged Radiator

Dirty coolant one thing that can create annoying engine problems. The function of the coolant is to maintain the engine at the right temperature for it to work properly. When the coolant is dirty, it reduces the efficiency of the radiator to cool the engine.

This eventually causes the engine to overheat, which damages other engine components. As a result, the engine will be too hot, and that is not a good sign. It is always advisable not to use tap water as the coolant since it can cause corrosion within the radiator.

4. Engine Coolant Loss

Engine coolant level reduces as a result of leakage. This is one of the most common causes of engine overheating. The best way to prevent this is to check the radiator, hoses, and other cooling system components for any signs of leaks.

Do a regular coolant check to ensure it is at its right level and in good condition. A healthy coolant is orange or green in color. Ensure that the coolant is clean and, if not, do a replacement. Keep in mind that overheating may lead to permanent engine damage.

5. Engine Overheating

Engine overheating is a problem that many car owners have come across. This would result from various things such as low coolant level, clogged hoses, a burnt-out radiator, or a blown head gasket loss.

Other causes of engine overheating are broken plugs or broken engine components. Overheating is a sign that should not be ignored. The excess temperature in the engine damages engine parts, which later leads to expensive replacements or repairs.

6. Bad Engine Noise

The unusual sound coming from the engine bay is a sign that there is something wrong with your car’s engine. If you happen to hear vibrations or knocking sounds from the engine, the vehicle needs an urgent checkup.

The engine knocking sound is caused by bad timing, lean fuel, and air mixture, bad knock sensor, worn bearings, or worn out belt tensioners. A mechanic will tell you which of these is causing the irritating noises and advice you accordingly.

7. Timing Chain Failure

The timing chain is an important part of the engine, and its failure can affect its performance. For your engine to work effectively, the timing chain has to rotate smoothly around the gears. If there is a problem with the timing chain, there will be some clear signs.

A problem on the timing chain will cause the engine to produce a rattling sound while running, misfire or run poorly. It will also lead to a lack of power and hesitation. Lastly, there will be metal shavings in the engine oil. If you see these engine problems symptoms, take the necessary steps at once.

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8. Faulty Sensors

A faulty sensor can cause severe engine problems. The engine in your car has various sensors, and they all perform different tasks. One of the most important sensors in your car is the oxygen sensor.

It measures the amount of unburnt oxygen in the exhaust gases. The car computer uses this data to adjust the air-fuel mixture. If there is an issue with this sensor, your car will receive incorrect information. This causes lower gas mileage or reduced engine power.

9. Car Not Accelerating Properly

If your car is not speeding up the way it used to, perhaps something is wrong with the engine. This problem is most common in high mileage vehicles. Some causes of poor acceleration are minor, and you can fix them easily when you discover them early.   

Poor engine acceleration can result from malfunctioning or clogged mass airflow sensor, malfunctioning oxygen sensor, timing belt, or the fuel filter. The issue can also be caused by low clutch fluid, worn-out clutch pedal, or errors in the ECU.

10. Smoke from the Engine

Blue or white smoke coming out of an exhaust pipe is a bad sign. If you see smoke coming out of your car, go to an auto repair shop immediately to fix it. Now, what can cause the smoke from the car exhaust? Well, there are various reasons why it happens.

One cause of blue smoke is high oil consumption. Other causes of blue smoke are worn valve guide seals, damaged piston rings, or poor crankcase ventilation. White smoke from the exhaust pipe is a sign of the engine burning coolant or a broken head gasket.

11. Engine Mounting Problems

What is an Engine mount? It is part of the car that holds the engine in place. If not taken care of, a faulty engine mount can cause engine problems. The primary issue with the mount is rubber parts separating or oil coming out of the liquid-filled mount.

The most common symptom of a failed engine mount is a noticeable jolt or thump when accelerating or decelerating. In some cases, it causes unusual engine noises. You can learn more about these in-car engine problems and solutions in pdf.

12. Engine Head Gasket Failure

Head gasket failure is a major engine problem. Replacing failed head gasket failure can be costly and take a lot of time. It can be a little difficult to pinpoint the exact cause of this failure. Most of the time, it is a result of a faulty cooling system. The best solution is to look for professionals and have them fix it.

13. High Engine Oil Consumption

Excessive engine oil consumption is never a good thing, and you should take it seriously. So why does it happen? Oil consumption mainly depends on piston rings and valve guide seals.

Damaged piston rings or leaking valve guide seals cause high oil consumption. This happens because the engine sucks the oil into the cylinders. As a result, your engine will consume a lot of oil.

14. Lubrication Issues

Your vehicle needs oil to reduce friction between moving parts. Oil also removes heat. A regular oil change helps your car to function properly. Lack of proper lubrication causes the engine to overheat. That is something you definitely want to avoid since it could damage the engine components of the vehicle.

15. Engine Knocking

At some point, the engine in your car may produce a loud knocking sound. This engine knock is also known as “detonation,” “spark knock,” or pinging. This issue occurs if fuel fails to burn evenly in the cylinders.

This results in annoying noises coming from the engine. But why does it happen? One of the common reasons is using fuel that is low in quality or octane value. It can also happen if you have the wrong spark plugs in your engine.

16. Dirty Intake Manifold

An intake manifold does an important job for your car. It disperses the air and fuel mixture to each engine cylinder. The intake manifold acts as a chamber in which the air and fuel mix.

Carbon and dirt buildup inside the intake manifold will have a negative impact on engine efficiency. When this happens, it will burn more fuel than necessary. That’s why it is essential to clean it periodically.

17. Stalling

Staling is when the engine stops suddenly, either while driving or coming to a stop. This is a common engine-related problem that should be taken seriously. A car stopping in the middle of a road with no warning is quite risky.

Various issues can cause this nuisance. Your engine might have a problem with fuel lines, a vacuum leak, or a faulty sensor. Bad spark plugs may also cause this problem. If this happens to your vehicle, have a professional check it immediately.

18. Piston and Piston Ring Problems

Pistons and piston rings are some of the key engine components. Pistons produce the power needed to move a car. With damaged pistons or piston rings, the engine in your car will produce less power.

There are several symptoms that will let you know there is something wrong with the piston and piston rings. They range from blue smoke in the exhaust, and engine misfire to loud rattling sounds. The oil filler cap and dipstick might pop off because of excessive crankcase pressure.

19. Oil Pump Problems

An oil pump provides enough oil for all engine parts. A malfunctioning oil pump causes oil starvation, which will lead to serious engine damage. Con Rod bearings and camshafts are the most vulnerable parts in this case.

A red ‘oil can’ warning light will pop up on your dashboard if there is a problem with the oil pump. If that happens, turn off the engine and have the vehicle checked and repaired.

20. Water in the Engine Oil

If the color of motor oil turns white, do not ignore it. It is a clear sign of mixing water with oil. Other possible causes are:

You must track down the cause of this problem to have an experienced mechanic resolve the issue.

21. Dirty Engine Oil

In time, motor oil becomes dirty or diluted. This is not good for your engine. If this happens, the best solution is to change the oil. Running an engine with contaminated oil will reduce its service life. The oil may be contaminated due to:

How to Diagnose and Treat Common Small Engine Problems On YouTube Video:

Final Verdict

Above, we have discussed the most common engine problems that you need to worry about. The engine is the most crucial part of your car, and you have to take care of it. Having known the problems you might face from your engine, you can now learn how to fix engine problems. You can solve some less serious issues at home, but others need an experienced mechanic.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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