30 Common Engine Problems and How to fix them

If you are looking for the most common engine problems, this post should help! When your engine fails, it isn’t a good thing. Not only will your car be down, but it can be hard to diagnose and even harder to repair.

Whether your engine is making weird noises, misfiring, or overheating, the cause could be one of many issues.

Most Common Engine Problems

You shouldn’t think of the check engine light as a death omen for your car, but you should think of it as an indication that something on your car needs some attention. Your car diagnostician may find any of the issues below.

#1. Aged spark plugs.

This issue is particularly prevalent in older vehicles. Spark plugs are designed to ignite the compressed fuel in your car’s engine.

An aged spark plug creates a weak ignition and can stop an engine from turning over i.e. misfiring. This is another issue that results in inefficient fuel economy and can also cause serious long-term damage to the engine.

#2. Overheating.

Overheating an engine can cause catastrophic failure usually requiring major repairs or a complete recondition.

Overheating usually happens due to coolant loss that can be a result of a bad radiator, thermostat, hose, water pump or a faulty cooling fan. It is important to have these items regularly inspected, serviced, or replaced.

#3. Engine Is Misfiring.

A misfiring engine is usually caused by worn spark plugs, although the issue could also be with the engine control unit, as well.

Spark plugs should be changed every 30,000 miles to every 100,000 miles depending on your vehicle manufacturer’s recommendation.

#4. 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 car to overheat.

#5. Failing oil pump.

Oil pump failure can lead to the inability of the oil to pump through its system. This situation can further lead to a shortage of oil supply to the necessary components of a vehicle’s engine, thereby resulting in poor lubrication.

Poor lubrication will increase the temperature with the engine’s operation and low oil pressure, damaging a vehicle’s engine.

Some easily noticeable symptoms of a failing oil pump are; oil pump noise, valve-train noise, hydraulic lifters noise, etc.

#6. Leaking Radiator.

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.

#7. Damaged Oxygen Sensors.

Another thing that can affect your engine’s performance, turn on the check engine light, and/or make your vehicle fail an emissions test is the oxygen sensor. This part will fail after about 80,000 miles to 100,000 miles of driving on average.

This sensor measures just how much oxygen hasn’t been burned in the exhaust. It will then tell the data system just how much gas is in the gas tank. A problem with an oxygen sensor means that your car gets incorrect information. This often causes lower gas mileage.

#8. Engine Stalling.

In a manual transmission, when the clutch pedal and gas pedal are not engaged at the right speed, your car will stop and require a restart–a frustrating and embarrassing event–especially in traffic.

Automatic transmissions don’t stall as often, but when they do, it serves as an indicator that something is wrong with an engine component. It is usually due to the intake stroke not receiving the right spark or air/fuel mixture.

If your transmission is stalling (either manual or automatic) have it seen by a professional as soon as possible.

#9. Poor Lubrication.

Improper Lubrication of all moving parts (pistons, rings, bearings, bushes, shaft & gears) can cause severe damage to your engine. Lubrication keeps moving parts (especially pistons & shaft bearings) cool.

To keep the engine clean, the detergent additive in oil cleans the inside of the engine & the oil carries the abrasive components & carbon to the filter.

Oil pickups can be blocked due to inadequate servicing which starves your engine of the oil it requires. Engine Problem recommends servicing your engine & vehicle regularly.

#10. Blocked engine radiators.

Blocked engine radiators can also aid overheating, as they are closely related to engine problems. Blockage of the engine radiator is usually due to old radiator fluid or a cooling system that has not been flushed over a long time.

A clogged radiator can lead to leakages, poor internal heating, water pump malfunction, overheating effects, damaged head gasket, etc.

To unblock the engine radiator, check the radiator and drain out the old coolant; then, flush out the particles by forcing water through the radiator. After that, refill the radiator using fresh coolant fluid with antifreeze.

#11. Noises.

Sometimes, engine problems give you warnings through noise. Some noises that a faulty engine will cause are backfiring, hissing, popping, and knocking. These sounds could mean problems inside the combustion flow.

Engine knocking, for instance, happens when there are pockets of burning air-fuel mixtures that burn on their own instead of being caused by a spark plug.

It can sound like there’s a knocking sound coming out of the engine and can cause a lot of costly damage to the engine if left unchecked.

#12. Oil Starvation.

Two things cause oil starvation: no motor oil or a failing oil pump. If either of these things happens in your engine, the parts will wear against each other and fail. Oil pump failure is more common in vehicles equipped with overhead cam engines.

#13. 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.

#14. Check Engine Light.

This light is the most obvious clue. It is usually located behind the steering column. When the check engine light turns on, it communicates that you could have any of a range of problems, including engine problems.

If the light blinks you may want to be more concerned. Regardless of how the problem presents itself, though, you will want to get it checked immediately as this will quickly diagnose the problem along with other possible trouble.

#15. 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 is due to broken valve seals, holes within cylinders, and overused piston rings, forcing air to leak out.

#16. Bad Fuel Injectors.

Fuel injectors play a crucial role in fuel delivery to the engine. They atomize the fuel and spray it into the combustion chamber, igniting it to power the engine, but they can become clogged with dirt, debris, and other contaminants.

Some common symptoms of clogged fuel injectors include reduced engine performance, poor fuel economy, bumpy idling, or a misfiring engine. You should have your fuel injectors cleaned every 30,000 miles.​​​​​​

#17. Engine Bearing Failure.

One of the most common engine problems is engine bearing failure. This can be diagnosed via a rattling or knocking sound coming from your engine, and it’s often indicative of worn-out bearings.

These are usually not expensive to replace, but they do require some time and effort on your part to get everything back together again.

If you notice that your car is making this kind of noise when you start it up, check for oil leaks around the front end of your vehicle—this could indicate that there’s a leak somewhere in the valve cover gasket or another seal between components inside the engine compartment.

Leaking oil combined with overheating could cause damage over time and lead to premature failure.

#18. Engine knocking.

Engine knocking occurs when pockets of air-fuel mixture burn on their own instead of being ignited by a spark plug. It is identified by a frequent knocking sound coming out of the engine. If left unchecked, it can cause a lot of damage and would require costly repairs.

One major cause of engine knocking is a bad air/fuel mixture. An oxygen sensor helps to maintain proper air and fuel levels in a vehicle’s running engine.

Any fault with this component can lead to a bad air/fuel mixture which can further produce a “knocking” sound in the engine.

#19. Detonation.

Detonation is caused by abnormal combustion inside the engine, which produces excessive heat & pressure inside the combustion chambers.

Over advanced Ignition timing or fuel with a low octane rating can create a knocking noise, also known as “pinging”.

Pinging is the noise created by two flame fronts colliding in the combustion chamber due to advanced ignition timing or higher compression ratio than suitable for the octane rating of the fuel used.

Detonation results in increased combustion temperature and unwanted piston and ring land damage.

#20. Blown Head Gasket.

The car engine runs in extreme conditions and intense heat, which can get a little out of hand sometimes and blow things up.

One of the most common culprits is the head gasket, which cushions pistons and cylinders from the cylinder head holding valves, spark plugs and camshafts.

The head gasket seals the cylinder’s firing pressure and prevents coolant and engine oil from leaking into the cylinders and outside.

Common symptoms of a blown head gasket include overheating, loss of engine power, white smoke from the exhaust, milky oil, and engine misfires.

#21. Engine Oil Leaks.

If there are brown puddles on the ground under your car, it could be due to an engine oil leak. Several factors could lead to engine oil leaks, such as a blocked oil filter, a loose filler cap, a damaged oil pan, or a broken gasket.

An engine oil leak can result in a loss of power and performance and will affect the longevity of your engine.

#22. Loss of Power.

A sudden drop in power while driving is the precursor to stalling and more serious engine damage. Your vehicle may stop or slow. When power comes back, it could jerk back into motion roughly and abruptly.

This extra movement may cause you to lose control on the highway or if you are driving in wet or snowy conditions or are navigating tricky off-road trails. And the cause of the problem may be more mundane than you think.

Many problems cause a sudden loss of power. Most notable, clogged fuel lines or subpar fluids can prevent your engine from running smoothly. Dirty fuel can clog fuel injectors, which fail to send adequate gasoline into each cylinder.

A badly clogged air filter can reduce the amount of fresh air reaching the engine, just as a dirty oil filter affects engine oil flow and performance. To get back on the road, you will need to carefully evaluate your entire engine and its fluids.

#23. Rough Idle.

A rough engine idle can be caused by several things, including a dirty air filter, a vacuum leak, or a problem with the ignition system.

If your car is having trouble idling, it’s essential to get it looked at by a mechanic right away. Ignoring the problem could lead to more serious engine damage down the road.

#24. Smoke or steam.

A smoking engine is never good news. You should immediately take your car to an auto repair shop if such a problem arises. The problem can happen because of worn gaskets, bad cylinders, damaged rings, poor crankcase, and using the wrong oil grade.

#25. Water In The Engine.

If you experience high waters or heavy rain that has entered into the engine, this can be a very bad sign. When water enters the engine, it can bend the piston rods, leaving your engine in really bad shape.

In many cases, water passes through the intake manifold where the spark plugs are located, another bad sign. Water issues can cause major problems if not addressed in a timely manner.

#26. Bad Fuel Pump.

Your car’s fuel pump does what it says on the tin, pumping fuel effectively from the fuel tank to the engine. If there’s an issue with the fuel pump or it suddenly stops working, it can lead to a number of symptoms including:

• Engine not starting
• Increase in fuel consumption
• Engine surges
• Sudden loss of power
• Temperature rise
• Engine splutter

These are just some of the signs that all is not well with your fuel pump.

Whenever your car starts to behave erratically, and it has some or all of these symptoms, ask your friendly mechanic to test the health and the life of the fuel pump. It’s a good idea to see if it needs to be replaced before it stops working altogether.

#27. Worn Combustion Parts.

Over time, the combustion parts in the combustion chamber — where air and fuel mix to power the engine — such as the pistons, cylinders, piston rings, valves, and spark plugs, can wear out, leading to a range of problems.

Piston rings are common culprits for wearing out in the combustion chamber. They are small and uncomplicated, but crucial parts that play a significant role in the indispensable precision of the engine’s function.

They help seal the chamber, lubricate the cylinder walls, and allow heat transfer. Symptoms include rough engine operation, blue smoke from the exhaust, engine oil disappearing, and reduced efficiency.

#28. Excess Combustion Pressure.

Too much heat and pressure in the combustion chamber can make your vehicle’s engine knock. We call this “spark knock,” and it sounds like pinging or knocking metal. Minor noise is bad but not devastating. Loud engine knocking can signal catastrophic detonation problems.

#29. Motor Oil Buildup.

The reason why your oil and filter should be changed every 3,000 miles is that as they age, they can leave sludge buildup throughout your engine. This sludge is deposited on the intake valves, and even on the spark plugs among other crucial engine parts.

#30. Lean Or Rich Air/Fuel Mixture.

To start, your car engine needs air and fuel in the combustion chamber so the spark plugs can ignite it. Too much air in the mixture creates a lean mixture that reduces your engine’s power. Too much fuel in the mixture makes it rich, and this can flood your engine.

#31. Leaking engine coolant.

One of the easier engine faults to diagnose is leaking engine coolant. If engine coolant is continually low once it’s topped up, it’s a surefire signal that there is a fault within the cooling system.

The coolant should be kept free of debris and deposits to maintain a safe operating temperature for your engine at all times.

How To Tell If Car Engine Is Blown

We’ve all heard people talk about blowing an engine, but what does that mean?  It’s easiest to understand a blown engine as any type of damage or failure that requires an overhaul or replacement of the engine.

There’s a number of various components that once damaged constitute serious enough repair that most would agree it’s “blown”.

Cracked Engine Block

One of the most obvious signs that you’re engine is blown is when the engine block cracks. The engine block is the larger housing that defines the internal combustion engine. 

If it cracks the engine cannot contain the pressures of fuel exploding and pushing the pistons to produce power.

Signs to watch for include if your vehicle is overheating if you have white smoke coming from the exhaust, and if you see coolant leaking from the side of the engine.

Pistons, Rings, & Cylinders

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 exhaust, oil caps popping off, when your engine won’t idle smoothly, and if you fail an emissions test.

What Causes Engine Failure?

Major causes of engine failure is due to Overheating, Improper Lubrication & Detonation.

Overheating an engine can cause catastrophic failure usually requiring major repairs or a complete recondition.

Overheating usually happens due to coolant loss that can be a result of a bad radiator, thermostat, hose, water pump or a faulty cooling fan. It is important to have these items regularly inspected, serviced or replaced.

Improper Lubrication of all moving parts (pistons, rings, bearings, bushes, shaft & gears) can cause severe damage to your engine. Lubrication keeps moving parts (especially pistons & shaft bearings) cool.

To keep the engine clean, the detergent additive in oil cleans the inside of the engine & the oil carries the abrasive components & carbon to the filter. Oil pickups can be blocked due to inadequate servicing which starves your engine of the required oil.

Engine Problem recommends servicing your engine & vehicle regularly.

Detonation is caused by abnormal combustion inside the engine, which produces excessive heat & pressure inside the combustion chambers. Over advanced Ignition timing or fuel with a low octane rating can create a knocking noise, also known as “pinging”.

Pinging is the noise created by two flame fronts colliding in the combustion chamber due to advanced ignition timing or a higher compression ratio than suitable for the octane rating of the fuel used.

Detonation results in increased combustion temperature and unwanted piston and ring land damage.

FAQs.