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Why Is My Car Making A Knocking Noise

why is my car making a knocking or clunking noise

Why is my car making a knocking or clunking noise

So, why is my car making a knocking noise? In this guide, we'll unravel the mystery behind that pesky knocking noise and equip you for suitable repairs, including average prices.

Have you experienced that heart-stopping moment when your car suddenly starts making a strange knocking noise? And you're left scratching your head, wondering what on earth could be causing it.

Stick around as we delve deep into the world of car clunks and knocks to uncover some of the most common issues.

Common causes of clunking and knocking noise

Possible solutions for diagnostic and fixes:

why is my suspension making a knocking noise
  • Suspension Issues: 

  • Diagnostic: Check for worn or damaged suspension components, such as bushings or struts. Listen for knocking noises while driving over bumps or rough roads.
  • Fix: Replace worn-out suspension components and ensure proper alignment for a smoother ride.
why is my car making a clunking noise
  • Loose exhaust components: 

  • Diagnostic: Inspect the exhaust system for loose or damaged components, such as heat shields or exhaust hangers. Listen for banging or tapping noises from underneath the vehicle.
  • Fix: Tighten or replace loose exhaust components to prevent rattling or knocking noises while driving.

wheel bearing making a knocking or humming noise
  • Wheel bearings:

  •  Diagnostic: Jack up the vehicle and check for excessive play in the wheels. Listen for a humming or grinding noise while driving, especially around corners.
  • Fix: Replace worn-out wheel bearings to eliminate knocking or humming noises from the back of the car.

why is my engine making a knocking sound
  • Engine idling noise: 

  • Diagnostic: Monitor engine RPM and listen for knocking or clicking noises while the car is idling. Check for issues with idle air control valves or fuel injectors.
  • Fix: Clean or replace idle air control valve and fuel injectors as needed. Ensure proper engine tuning and maintenance to prevent idling noise issues.

 gearbox making a noise
  • Transmission noise:

  •  Diagnostic: Listen for knocking or clicking noises while changing gears. Check transmission fluid levels and condition.
  • Fix: Service or replace worn-out transmission components, such as gears or bearings. Ensure proper transmission fluid levels and maintenance to prevent noise or further damage 

why is my car making a knocking or clunking noise
  • Drivetrain problems: 

  • Diagnostic: Listen for clunking noises during acceleration or deceleration. Check for worn or damaged CV joints, driveshafts, or differential components.
  • Fix: Replace worn-out drivetrain components and ensure proper lubrication and alignment. Additionally, address any issues with CV joints or driveshaft balance to eliminate clunking noises.

why is my car engine knocking
  • Engine knocking noise: 

  • DiagnosticMonitor engine performance and listen for knocking noises while accelerating. Firstly, check for issues with the cambelt or chain. Secondly, check for low oil pressure, valve lifter failure, spark plugs, or a bad fuel pump.
  • Fix: Replace worn or damaged engine components, such as cambelt or chain, valve lifters, or spark plugs. Ensure proper lubrication and oil pressure to prevent engine knocking.

 car oil pressure light on causing knocking noise
  • Possible solutions for low oil pressure: 

  • Diagnostic: Check the oil level using the dipstick. If it's low, top up the oil to the recommended level.
  • Inspect for any oil leaks under the car or around the engine.
  • Use an oil pressure gauge to measure the actual oil pressure in the engine.

  • Fix: If the oil level is low, top up with the appropriate grade of oil recommended by the manufacturer.
  • If there are leaks, identify and repair them promptly to prevent further oil loss.
  • If the oil pressure is consistently low despite proper oil levels and no leaks, it may indicate a faulty oil pump or worn-out bearings. Consult a mechanic for further diagnosis and repair.
failing fuel pump

  • Possible solutions for bad fuel pump: 

  • Diagnostic: Listen for a whining or humming noise from the fuel  tank area while the engine is running. This may indicate a failing fuel pump.
  • Use a fuel pressure gauge to measure the fuel pressure at the fuel rail. A significantly lower than-normal pressure may indicate a failing fuel pump.
  • Check for any error codes related to fuel system issues using a diagnostic scanner.

  • Fix: If the fuel pump is confirmed to be faulty, it will need to be replaced. This typically involves removing the fuel tank to access the pump assembly.
  •  Replace the fuel filter along with the fuel pump to prevent any debris from entering the new pump.
  • Follow the manufacturer's recommendations for fuel pump replacement and ensure proper installation to avoid any issues with fuel delivery.

DIY or call a professional mechanic

When to seek professional help for car knocking noise:

        Non-engine causes of  knocking  and clunking noises:

  • Worn wheel bearings, suspension issues, or loose exhaust components can also produce knocking noises.
  • Check these potential causes before diving into engine diagnostics.

Recap: Addressing knocking noises quickly and safely is crucial for maintaining your car's health. Understanding the common causes of engine knocks and knowing when to DIY or seek professional help

Remember, don't ignore knocking or clunking noises – take action and nip the problem in the bud for a safer and smoother ride. 

Is it safe to drive with a clunking or Knocking noise?

  • It's not recommended to drive with any kind of knocking noise as it could indicate underlying issues with critical components like suspension, transmission, or drivetrain.
  • Equally important, continuing to drive with unresolved clunking noises may lead to further damage and compromise vehicle safety.
  • It's best to have the vehicle inspected by a qualified mechanic to diagnose and address the root cause of the clunking noise promptly.

What to do if your engine is clunking or knocking:

  • Stop driving immediately and safely pull over if you notice clunking or knocking noises from the engine area.
  • Check oil levels and ensure proper lubrication. Low oil pressure can contribute to engine knocking.
  • Have the vehicle towed to a mechanic for a thorough inspection and diagnosis. Ignoring engine knocking can lead to severe damage and costly repairs.

Understanding your engine:

How does your car engine work?

  • Your car's engine is like the heart of your vehicle, powering it forward.
  •  Various components, including cylinders, pistons, spark plugs, and fuel injectors.
  • When you start your car, fuel mixes with air in the cylinders and ignites, creating controlled explosions that drive the pistons and turn the crankshaft.

        How do engine knocking noises occur:

  • A knocking noise happens when the air-fuel mixture ignites prematurely, causing erratic banging sounds.
  • This can occur due to improper fuel combustion, engine overheating, or worn-out components.

The importance of engine service and regular maintenance

From road trips to daily commutes, our trusty vehicles take us where we need to go. But to keep them running smoothly, regular maintenance is key. The importance of engine service and regular maintenance to keep the knocking and clunking noises at bay.

Why engine service matters:

1. Ensures optimal performance:

  • Regular engine service helps keep your car running smoothly and efficiently.
  • Routine oil changes, filter replacements, and tune-ups maintain engine health and performance.

2. Prevents costly repairs:

  • Neglecting engine maintenance can lead to costly repairs down the road.
  • Regular service helps identify and address issues early, saving you money in the long run.

3. Improves fuel efficiency:

  • A well-maintained engine operates more efficiently, leading to better fuel economy.
  • Regular tune-ups and air filter replacements can help improve mileage and save you money at the pump.

Regular maintenance on brakes:

1. Brake pad inspection:

  • Regularly check brake pads for wear and tear.
  • Replace brake pads if they are worn down to prevent brake failure and ensure safety.

2. Brake fluid flush:

  • Brake fluid should be flushed and replaced according to manufacturer recommendations.
  • Fresh brake fluid ensures optimal braking performance and prevents corrosion in the braking system.

3. Rotor resurfacing:

  • Over time, brake rotors can develop uneven wear patterns.
  • Resurfacing the rotors ensures smooth braking and prolongs the life of the braking system.

Regular maintenance on suspension:

1. Shock absorber inspection:

  • Check shock absorbers for leaks or signs of wear.
  • Worn shock absorbers can affect vehicle stability and comfort, so replace them as needed.

2. Bushing and linkage check:

  • Inspect suspension bushings and linkages for signs of damage or deterioration.
  • Replace worn bushings and linkages to maintain proper suspension alignment and stability.

3. Wheel alignment and balancing:

  • Regular wheel alignment and balancing ensure even tyre wear and optimal handling.
  • Proper alignment reduces stress on suspension components and improves the overall driving experience.

Regular engine service and maintenance on brakes and suspension are essential for keeping your car in top condition.

By staying on top of routine maintenance tasks, you can ensure optimal performance, prevent costly repairs.

Remember, a well-maintained car will reliably take you wherever you need to go.

So, don't skip out on your car's TLC – it's the key to a smooth ride and peace of mind on the road.

regular car maintenance


In conclusion, finding out why your car is clunking or knocking can be various issues, ranging from suspension problems to engine issues.

Address these noises quickly to prevent further damage and ensure vehicle safety.

Regular maintenance, timely inspections, and prompt repairs are key to keeping your car running smoothly.

Unsure why your car is making a knocking noise or how to fix it, seek professional assistance from our recommended qualified mechanics.

Remember, safety always comes first when it comes to vehicle maintenance and repairs.

About the author

My name is Karl Scott
I started my blog because because I wanted to share the wealth of knowledge and experience I've accumulated over the years, and to connect with others who share my passion for cars.

Through my posts, I plan to focus on simple DIY repair tutorials, maintenance tips, and how to spot potential issues before they become major problems.

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