40 Common Engine Problems and How to fix them

The engine is the heart of any functioning car. It’s one aspect of looking after and running a vehicle that you simply can’t compromise. Diagnosing a fault with your engine is not always easy and it can be even harder to repair.

If you believe that your engine is struggling or, worse still, failing, make sure you take a look at the nine most common issues relating to car engine failures below. Not all engine problems are serious and can be remedied relatively quickly, but all of them can cause engine breakdowns and, in the worst-case scenarios, require a brand-new engine.

Common Engine Problems and How to fix them

Here are some common engine failures that most car owners face and how to diagnose engine problems:

#1. Engine Is Misfiring.

Engine misfires happen when one of the cylinders does not produce sufficient spark or compression and lack of fuel. It could involve more than one cylinder. It can be caused by a faulty spark plug, fuel injector, ignition coil, and or worn cylinder.

Signs that an engine Is misfiring include slower acceleration or shaking during acceleration; the engine also might hesitate or briefly lose power. At idle, the engine might vibrate more than usual and run unevenly. Misfires can occur when an engine is cold or warm, and they can occur intermittently.

Misfires usually cause the check engine light to illuminate. Fuel economy also is likely to suffer, and emissions might increase because unburned gasoline is exiting the engine.

#2. Dirty Engine Coolant.

If you’ve driven over 100,000 miles or your car is five years old and you’ve never had your radiator flushed and refilled, you probably have dirty coolant. The sediment in the dirty coolant will clog your radiator and this will cause your automobile to overheat.

#3. Leaking Cooling System Parts.

Another reason why your vehicle will overheat is leaking coolant. As the coolant leaks out of the radiator, radiator hoses, gaskets, seals, overflow reservoir, water pump, or another cooling system part, the level gets too low for the coolant to be effective.

#4. Poor lubrication.

Your engine must receive 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.

#5. 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.

#6. 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.

#7. 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.

#8. 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.

#9. 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.

#10. 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.

Related Post: Top Reasons Why Your Car Won’t Start

Common engine problemss

#11. 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.

#12. 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.

#13. 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.

Related Post: What Happens If You Drive with Low Coolant?

#14. 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.

#15. 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.

#16. 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.

#17. 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.

#18. 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 sensors, 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.

#19. 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.

#20. 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.

#21. 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.

#22. 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.

#23. 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.

#24. 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.

Related Post: What is Engine Knocking and How Can I Fix It?

#25. 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.

#26. 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.

#27. 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.

Several symptoms 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.

#28. 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.

#29. 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.

#30. 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

#31. 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.

#32. 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.

#33. 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.

#34. 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.

Related Post: What Causes A Radiator Leak and How To Fix Them?

#35. 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.

#36. There are gearbox 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.

#37. 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.

#38. 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.

#39. 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.

40. 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.