51 Common Engine Problems and How to fix them (2024)

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. Poor lubrication

It’s absolutely vital that your engine receives enough oil between its moving parts. A lack of lubrication will cause unnecessary friction inside the engine, leading to overheating and worse still, the engine seizing up.Make sure that you get your vehicle periodically serviced, which includes a regular oil change to keep quantities at an appropriate level.

2. Failing oil pump

The failure of an oil pump is extremely serious for the lifespan of any engine. If an oil pump fails it will almost certainly starve the engine of necessary lubrication. Always ensure that the engine oil you use in your engine is of a genuine viscosity, making it light enough to flow fast through the pump.

3. Oil deposits and debris

Older, dirty oil has the propensity to leave deposits and debris on engine fittings such as intake valves and spark plugs, not to mention combustion chambers. As part of a periodic service at your local garage, they will regularly clean your engine’s oil filters to avoid debris becoming lodged within your vehicle’s bearings.

4. Inadequate fuel and air compression

Poor compression of both fuel and air inside a car engine is a recipe for disaster. The most common reasons for poor engine combustion are due to broken valve seals, holes within cylinders, and overused piston rings, forcing air to leak out.

5. Prolonged engine detonation

If you are driving along and your engine is making a knocking noise it is quite possible that there is too much heat within its combustion chamber. A combination of overheating and high pressures creates engine detonation, also known as a spark knock, which can cause long-term damage to pistons, head gaskets, and piston rings.

6. Damaged oxygen sensors

An inaccurate oxygen sensor is dangerous not only for your engine but for the rest of the car too. If the sensor does not give your car the right data about how much oxygen remains in the exhaust and how much fuel is in the petrol/diesel tank, you run the risk of inefficiencies with your driving, wasting lots of money in the long run.

7. 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.

51 Common Engine Problems and How to fix them (1)

8. 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.

9. Clogged Radiator

Old engine coolant that’s not been kept clean over time can result in filling your engine’s radiators with unwanted sediment and deposits. This is another common cause of overheating engines. Try to avoid using hard water as a coolant because you will run the risk of the radiators corroding over time due to limescale.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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.

17. Engine Mounting Problems

What is an Engine mount? It is the 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.

18. 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.

19. 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.

20. 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.

21. 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.

22. 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.

23. 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 within 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.

24. Piston and Piston Ring Problems

Piston 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, engine misfire to loud rattling sounds. The oil filler cap and dipstick might pop off because of excessive crankcase pressure.

25. 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.

26. 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:

  • Cracked engine head
  • Faulty oil cooler
  • Cracked engine block

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

27. 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:

  • Poor fuel quality
  • Clogged or damaged air filter
  • Damaged engine oil filter

28. A Warning Light Shows

Warning lights appear when one of the sensors detects an error and highlights it to the engine control unit. There are around 200 warning codes so you will need to take this to a professional who can then check the system, find out the source of the warning and carry out the necessary repairs.

29. The Engine is Sputtering

There are multiple parts that keep an engine running well but a misfiring or sputtering engine is one of the most common issues. For an engine to run efficiently the right amount of air and fuel must mix and then burn within the combustion chamber.

In order for this to run correctly, there are a number of components in the fuel and ignition systems that have to work in unison. In order to keep these types of issues to a minimum, the fuel and ignition systems must be maintained and replaced according to the manufacturer’s recommendations.

30. The Steering Wheel is Shaking

There are a number of reasons why a steering wheel shakes when driving a vehicle. Damaged suspension components or wheel bearings are usually to blame if this happens immediately after you start the car and pull away.

If the wheel shakes at higher speeds it is more often an issue with tire/wheel balance. To resolve this, you will need to take the car for a proper mechanical inspection. It could be as simple a fix as getting your wheels aligned.

31. The Brake Pads are Worn

Brakes will naturally wear down with use so it is vital that you keep on top of maintenance and make sure any problem is resolved long before the brakes fail. Sometimes factory defects mean that brake pads and rotors wear out more quickly than they would normally.

32. The Brakes are Squeaking/Grinding

The brake system will start to wear out just like any other moving part you have in the car. Brakes are vital – they are essential to make sure you can stop safety so any kind of brake-related problems, including unusual noise or a soft brake pedal, should be taken care of by a professional mechanic at the earliest possible opportunity.

There are some minor issues that can cause brakes to squeak or squeal but once you start to notice grinding you definitely need to get them replaced.

33. The Tires are Flat

A tire will obviously be flat if it is punctured but it can also be caused by normal wear and tear. Keeping the tires rotated in accordance with the manufacturer’s instructions can help extend their life. The best practice is to rotate the tires when you change your engine oil or every 5,000 miles.

34. The Tires are Wearing Unevenly

A certain amount of wear over time is normal but if you find that the tires wear down quickly this indicates a potential problem. If there is vibration through the steering wheel or you find that your tires are wearing unevenly you should ask someone to check the vehicle. It could be that the suspension needs alignment. In addition, sometimes tire problems are caused by external factors or by defects in manufacture.

35. The Car is Consuming Too Much Oil

Fresh oil is essential for a car to function but if you are constantly topping up your oil level you may have a problem with the car. If you start to notice a drop-off in performance or the oil light comes on you will definitely need to check the oil.

If you don’t get the oil changed regularly you might find that the engine becomes corroded. Poor quality oil or lack of regular changes can also cause blockages in the oil filter. It is best to change the oil filter at the same time as you change the oil although some modern cars do have a filter bypass system in place.

36. The Alternator is Failing

The alternator is an essential part of the running of your car – it keeps your battery charged and makes sure all the electrics run once you have started the vehicle. If it breaks your battery can wear out and you find it difficult to start the car. Keep up with the service intervals and make sure you get it replaced in good time.

37. The Radiator is Leaking

Radiator leaks are almost always caused by corrosion. Corrosion itself can have a lot of causes but once you get one leak you are likely to get more so it makes sense to replace the whole radiator. If you don’t keep the radiator in good condition, you can get problems with overheating and, ultimately, could end up with an engine fire.

38. The Starter Motor is Failing

The starter motor is the component that turns the engine over when you start the car. If it fails it is either a result of electrical solenoid damage, the motor itself has broken or there are other faults in the electrical system.

It is difficult to assess when a starter motor is likely to break and to avoid replacing it unnecessarily it is best to get the car inspected by a professional to determine the cause of the starting issues before doing so.

39. There are Cracks in the Windscreen

Usually, it takes some kind of external force like a stone to crack a windscreen but there are some cars that are prone to damage because of factory production vulnerabilities. Although a small crack might not seem like a big deal, it can spread rapidly and compromise the integrity of the glass.

40. The Car Gives Out Excessive Emissions

The emission system is designed to keep pollution to a minimum while making sure your car runs properly. The system includes a lot of sensitive equipment that can fail from time to time and these cause a variety of different problems in the car. For example, an O2 sensor that is faulty may start affecting the fuel mixture, leading to inefficiencies in the running and economy of the vehicle.

41. There are Fuel Leaks Through Evaporation

Fuel is sensitive to temperature and when it is hot the fuel will expand. This means that there has to be some way of venting the fumes. Since the fumes are toxic modern cars are fitted with equipment to stop that toxicity from reaching the outside.

The main problem you get with this is leaking through evaporation. Most problems happen with the fuel cap and it is easy and cheap to replace these regularly. However, if you see a warning light never ignore it – if you end up with a failure in the catalytic converter the repairs could be costly.

42. The Sensors Are Malfunctioning

Most modern cars come with a vast number of sensors but these can have issues in and of themselves. One of the most common faults is with the fuel-air sensors and these are costly to replace, often in excess of £200.

43. There are Gear Box Problems/Transmission Failures

The gearbox means that all of the power your car engine generates can be turned into the sort of rotational force that can be used by the wheels. Over time the gears will start to wear down and you will find that it becomes more difficult to change gears. Eventually, the gearbox will fail, leading to a repair bill that could potentially reach thousands of pounds.

  • The Transmission Fluid is Leaking: Any transmission system needs fluid to make sure all of the working components are kept well lubricated. In automatic cars the fluid used in transmission is also used in the hydraulic and coolant systems. Small holes can form throughout the system which allow tiny amounts of fluid to leak. Over time, or if the leaks are severe, you will find that transmission is less efficient, plus you may find that the system overheats or loses pressure. In both cases the transmission will fail. If you see a red puddle collecting under your car it can be a sign that the transmission pan is cracked.
  • The Automatic Transmission is Slipping: Automatic transmission can be long-lasting and efficient if well-maintained. It is not unreasonable for it to last over 200,000 miles. If you start to find the transmission is less smooth or slips it could be that there is damage or clogging in the seals, gaskets and lines inside the system. The transmission should be serviced regularly to avoid this.
  • The Transmission Filters are Clogged: Just like any other fluid, transmission fluid will pick up all sorts of particles over time and many of these end up in the filter which then become clogged and need replacing. However, the transmission system is closed meaning that if you are getting issues with clogging and blockages it is likely to be down to some serious problems that could be beyond repair.
  • There’s Water in the Transmission System: Water and other liquids can enter the transmission system and if it does it always means bad news for the car owner. In even small amounts water will damage the components in the system and lead to transmission failure.

44. Electrical Problems

  • Speakers: Most new cars come with extensive electrical systems meaning that problems can occur in multiple areas. One of the most immediately noticeable, and some would say annoying, faults is when the speakers fail. Sometimes this is as simple as a wire working loose and is easily fixed by removing the speaker and reattaching the faulty wire.
  • Lights: Lighting is always a safety issue especially if it is a headlight, brake light or indicator that is gone. Corrosion and wiring can cause bulb issues but most bulbs last a long time before falling foul of normal wear and tear.
  • Flat Battery: Flat batteries are inconvenient – and can also be a major source of stress. It could be that you have left a light on accidentally or something minor that can be simply sorted out by jump-starting the car. A flat battery can occur because the battery is old and has lost the ability to keep a charge. A battery older than 3-6 years or one that has travelled over 50,000 is due for replacement. Other causes include alternator failure of problems within the charging system.

45. There are a Few Minor Issues:

Scratches, Streaking Wipers, and Poor Paintwork: These things are often annoying but don’t need immediate attention. Fixing them is also cheap and easy: Some cleaner wax and paint to cover scratches, new windscreen wipers cost just a few pounds and paint defects are nearly always cosmetic. If you do see any small rust spots, make sure you deal with these so they don’t turn into a bigger problem later on.

46. Window Problems

Most new cars have electric windows and one of the major bug-bears of car owners is when they stop winding all the way up. It isn’t just annoying either – a gap can mean water can enter the car interior and damage it, or you could become more of a target for thieves.

47. Faulty Starter

If it’s hard to start your car you may be starting to hear a click before the car starts – if this is the case it could be time to replace your starter motor. If it goes the car will no longer start so it needs fixing sooner rather than later.

48. Rust

It can come as a shock to find rust on your car though it doesn’t always represent a serious issue it depends on where the rust is found. Rust on the bodywork is cosmetic but rust underneath the car or on your exhaust could be potentially dangerous and should be investigated as it could eat away at essential components.

49. My Fuel Economy is Falling

If the engine runs efficiently, it will burn fuel at a better rate but if parts of the systems start to wear out and are not replaced you will find the mileage will drop. Keeping on top of things like your fuel and air filters, O2, and mass air sensors, with a proactive servicing regime will keep your car running efficiently.

The bottom line is that fuel economy depends on how well you maintain the engine. Making sure that the vehicle is regularly serviced, with appropriate oil changes, filter changes and new spark plugs can make all the difference when it comes to mileage.

50. Cylinders

The pistons are what does the heavy lifting of producing the power to move your vehicle. They go up and down within the cylinder walls and the rings close up the gap between the piston and the walls. If any of this is damaged the engine will have serious failures and need to be repaired or replaced.

Symptoms to watch for with your pistons, rings, and cylinders are loud rattling sounds, blue smoke in the exhaust, oil caps popping off, when your engine won’t idle smoothly, and if you fail an emissions test.

51. Rods, Bearings, & Pins

Other components in your engine that transfer the power from the pistons such as the rods, bearings, and pins will cause a blown engine if they fail.

Things to watch for include tapping and ticking sounds, low oil pressure, pulsing, metal shavings in the engine oil, throwing a rod (extremely dangerous), and rattling when you accelerate.

51 Common Engine Problems and How to fix them (2024)
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