A car engine is a complex machine that converts fuel into energy and powers the vehicle. Any issue with the engine or its parts can result in costly repairs.
It is important to have a basic understanding of engine parts and their common problem. This information helps identify problems with the engine and saves you from costly replacement of engine parts.
This guide provides information about key engine components and their everyday problems.
Article Highlights
- Key components of the Engine
- Common Engine Problems
- Methods of Engine Diagnostics
Types of Car Engines
Engines are classified according to the fuel they use and how they generate power. The main ones are petrol (gasoline), diesel, hybrid, and electric engines.
Petrol and diesel engines work similarly. They mix fuel and air, which burn in small explosions inside the engine, which moves the pistons. The pistons turn the crankshaft, which then makes the wheels spin.
Hybrid engines combine this fuel-burning system with an electric motor, while electric vehicles (EVs) run entirely on electricity stored in batteries.
Key Components of an Engine
All engines are built around a few main pieces working together. The Engine Block forms the body, containing the hollow Cylinders. Inside these cylinders, the Pistons move up and down like a pump. These pistons are connected to the Crankshaft by Connecting Rods. These rods convert the pistons’ up-and-down movement into circular motion, which is required for wheel rotation.
The Cylinder Head sits on top and holds the Valves. The valves open and close at precise times to let air and fuel in and exhaust fumes out. Additionally, the engine has a Camshaft, which controls the timing of these valves.
Petrol engines use a Spark Plug to ignite the fuel mixture, while diesel engines use high compression for ignition. All engines also need systems to circulate oil (lubrication) to prevent friction and water (cooling) to prevent overheating.
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Common Engine Problems
Even a well-maintained engine can develop faults. Knowing the symptoms helps you act fast. Ignoring problems can cause expensive damage.
The most frequent problems are the engine not starting, stalling, or making unusual noises, and the “check engine” light coming on. Issues with the cooling, lubrication, and ignition systems often cause these problems.
Overheating
A car engine can get dangerously hot, and you might see the temperature gauge spike or steam coming out of the bonnet. Overheating happens for several reasons. A low coolant level or a faulty radiator can stop cooling.
Overheating can warp the cylinder head, which is very expensive to fix. If your engine overheats, you should stop driving immediately and let the engine cool down.
Oil Leaks
Oil leaks are mostly noticed as a puddle under your car. Leaks can come from various seals and gaskets in the engine, and the sump plug can also leak.
Sometimes, a small leak is not that serious. It usually happens due to a loose oil pan and can easily be fixed. Synthetic oils sometimes seep more visibly but are not necessarily a problem. However, a large leak is dangerous. It can be due to excessive oil pressure. It leads to low oil levels and major component wear, which can result in engine failure.
Knocking Sounds
Engine noises are never good. A knocking or pinging usually signals pre-ignition, which means the fuel ignites too early. Additionally, worn bearings can also create noise. Bearings hold the moving parts of the engine, and when they are worn out, they lose grip and cause parts to bang together. This can further damage the banging parts of the engine and requires urgent professional attention.
Poor Fuel Efficiency
Several engine issues cause poor fuel efficiency. The most common one is a clogged air filter. Faulty spark plugs can also lead to incomplete combustion, which requires more fuel for the engine to start. A failing oxygen sensor also gives incorrect fuel mix readings and wastes fuel. This will result in frequent trips to the pump and cost more in fuel.
Also Read: 7 Signs of Poor Wheel Alignment That Cost You Money
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Exhaust Smoke
The colour of your exhaust smoke tells a story about your car engine. Blue smoke means the engine is burning oil, which often points to worn piston rings or valve seals.
White smoke often means the engine is burning coolant. It usually indicates a blown head gasket, which requires major repair. However, it is important to note that some car engines have white smoke on a cold morning, which is basically steam and is not anything to be worried about.
Cars with dirty air filters or major issues, like a fault in fuel injectors, release black smoke. This means the engine is burning too much fuel. Excessive exhaust smoke (especially blue or black smoke) causes the vehicle to fail the Emissions Test, which is a major part of the MOT.
Common Methods of Engine Diagnostics
When your engine develops a fault, mechanics use special methods. They need to find the exact problem fast. This saves time and cost.
Onboard Diagnostics (OBD) Scanning
The easiest first step is the OBD scan. All cars sold in the UK since 2001 have an OBD scanning system. It constantly monitors engine performance and stores a Diagnostic Trouble Code (DTC) for any fault detected by the system.
Mechanics use an OBD scanner tool. They plug it into a port under the dashboard. The scanner reads the DTC. The code points the mechanic to the problem area. For example, a code might say ‘Misfire in Cylinder 3’, which narrows down the fault search.
Visual Inspection
You should always perform a thorough visual inspection. It often finds the cause of an engine problem immediately. Check for leaks (oil, coolant) and look at the condition of hoses and belts. You should also inspect the battery terminals for corrosion and check the air filter for dirt.
Computerised Engine Analysis
If the initial testing fails to identify the root cause of the car engine problem, consult a professional car repair technician. They perform computerised engine analysis and monitor data in real time, which shows how sensors and engine components are performing. Computerised engine analysis reveals the fuel mix and ignition timing of the engine. This helps diagnose faults within internal engine components, which are mostly noticed only under specific driving conditions.
Sensor Testing
Engine performance relies on sensors. The oxygen sensor checks exhaust gas. You can get these sensors tested by a mechanic. They use a multimeter and check the sensor’s voltage output. If the output is wrong, the sensor needs replacing.
Compression Testing
Good compression is vital for a strong power stroke. To check compression, the mechanic removes the spark plug and screw a special gauge into the hole. Then the engine is turned on, and the gauge measures the pressure the piston creates. Low compression means a problem. This could be a worn piston ring or a damaged valve.
Newer hybrid and EV systems require advanced diagnostic tools. AVX provides these specialised services. Our team handle the complex software and high-voltage repairs of your modern vehicle.
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Conclusion
Your car engine is a marvel of engineering. Understanding its basics is empowering. Recognising common problems helps you act fast, and using modern diagnostic methods ensures quick, accurate repair. Don’t ignore the warning signs. Regular maintenance is always the best defence. Anyone needing professional vehicle care can contact AVX Auto Repairs. We offer a range of services, from routine maintenance (servicing, oil changes, engine diagnostics) to bodywork and accident repairs. Look after your engine and stay safe on the roads.
Frequently Asked Questions
You should not drive with an oil leak for long. A small leak might be manageable for a short time, but constantly checking the oil level is essential.
Engine timing is the precise synchronisation of the crankshaft and camshaft. It ensures the valves open and close exactly when needed. Bad timing can severely damage the engine.
You should change your engine oil according to your car’s manufacturer’s recommendations. This is usually every 6,000 to 10,000 miles or once a year, whichever comes first. Using the correct type of oil is also crucial.
Yes, an engine air filter is a standard and essential component in a car’s engine. Its purpose is to filter dirt, dust, and other debris from the air, which the engine uses for fuel combustion.
2000cc is a simple way to say a car has a 2.0-litre engine. It tells you the size or capacity of the engine. These engines are commonly found in a range of vehicles, including compact cars, mid-sized sedans, and some small SUVs.
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Don’t let a major engine issue become an expensive MOT failure on emissions or warning lights! Contact AVX Auto Repairs today for a free service consultation.
