Why Is My Car Making A Knocking Noise and How to Fix It?

If your car is making a knocking sound. It can be unsettling and with good reason. Knocking sounds indicate underlying issues that need attention before they worsen. At Perth Auto Mechanic, we know how these noises can leave you scratching your head.

Wondering if your vehicle is safe to drive or if the repair bill will be sky-high. Let’s explore why these sounds occur. How they’re fixed and why addressing them early can save you time, money, and headaches.

What Causes Engine Knock in Your Car?

Engine knocking, often referred to as “engine knock,” happens when there’s an issue with how the air-fuel mixture ignites inside the cylinders. Instead of burning smoothly, it detonates unevenly, creating that knocking or pinging noise you hear. But what is engine knocking caused by? Let’s break it down step by step.

1. Low-Quality Fuel or Wrong Octane Rating

Using low-octane fuel in a car designed for high-octane gasoline can lead to knocking. The lower the octane, the more prone the fuel is to pre-ignition or detonation, especially under high pressure.

Solution: Switch to the recommended octane fuel for your car. It’s a simple fix, and your owner’s manual should tell you which fuel grade to use.

2. Carbon Build-Up in the Engine

Over time, carbon deposits can form inside your engine’s cylinders. These deposits reduce the space where the air-fuel mixture ignites, increasing pressure and leading to knocking.

Solution: A professional engine cleaning service can remove carbon buildup. At Perth Auto Mechanic, we use specialized tools to clean your engine thoroughly and restore optimal performance.

3. Worn or Damaged Engine Parts

Certain components, like pistons, rods, bearings, and valves, are critical for smooth engine operation. If they’re worn out or damaged, they can create a knocking sound.

Solution: Depending on the part causing the noise, repairs may involve replacing worn bearings, adjusting valves, or even replacing damaged pistons. These are precise repairs that require professional tools and expertise.

Is It Safe to Drive with Engine Knocking Sound?

Short answer: No, it’s not safe.

Driving with a knocking engine worsens the problem. Prolonged knocking increases wear and tear on internal components like pistons and bearings. Potentially leading to severe damage like a cracked piston or a failed crankshaft. If you hear persistent knocking. If left unchecked. It can lead to engine failure. Which is far more expensive to fix.

The moment you hear a knocking sound. Bring your car to Perth Auto Mechanic. We’ll identify the issue early and save you from costly repairs down the line.

How Knocking Damages Your Engine

Ignoring a knocking noise isn’t just risky—it can be catastrophic. When the combustion process doesn’t occur as intended, it creates shockwaves that stress engine components. Over time, this can cause:

• Piston damage: Holes or cracks in the pistons can result from consistent knocking.
• Cylinder wall wear: Uneven combustion erodes the walls, reducing engine efficiency.
• Bearing failure: Excess vibrations damage the crankshaft bearings, potentially leading to complete engine failure.

The key takeaway? The sooner you address a knocking noise, the less likely it is to result in costly repairs.

Why do I hear knocking sound when I accelerate?

Do you hear the knocking sound intensify when you press the gas pedal? That’s often due to pre-ignition or detonation—essentially, fuel ignites too early in the combustion cycle.

Why Does This Happen?

• Lean air-fuel mixture: When there’s more air than fuel in the mixture, it burns unevenly, causing knocking.
• High engine load: The harder your engine works, the more likely it is to knock if conditions aren’t ideal.
• Heat and pressure: Combustion chambers get hotter during acceleration, increasing the chance of premature fuel ignition.
• Faulty spark plugs or ignition timing: If your spark plugs are old or misfiring, or if the timing is off, the fuel might ignite at the wrong time.

If this describes your car, you’re not alone. Many drivers experience this problem. Replacing spark plugs or ignition coils is a common fix. Adjusting the air-fuel ratio or repairing the fuel injectors can also resolve the issue. It’s one we frequently address at Perth Auto Mechanic.

How Do You Fix a Knocking Engine? | Visit Perth Auto Mechanic

When your engine is knocking. We use a systematic approach to diagnose and resolve the issue. Here’s what goes into fixing it.

Step 1: Diagnostic Testing

Using advanced diagnostic tools. We pinpoint the exact cause of the knocking noise. We scan your engine for trouble codes and inspect key components like spark plugs, fuel injectors, and ignition timing. This involves:

• Testing the air-fuel ratio.
• Checking fuel quality and type.
• Examining the engine for carbon deposits.
• Inspecting the spark plugs and ignition system.

Step 2: Repair or Replacement of Faulty Components

Once we’ve identified the problem. Here’s how we fix it.

• Spark plugs: Worn or damaged spark plugs are replaced to restore proper combustion.
• Fuel system: If low-quality fuel caused the issue. We flush the system and recommend using higher-octane fuel.
• Carbon deposits: Special cleaning agents or mechanical cleaning methods remove stubborn build-ups.
• Engine bearings: If worn bearings are the culprit. We replace them to ensure smooth crankshaft movement.
• Fuel System Repair: If the issue stems from a lean air-fuel mixture. We repair or replace fuel injectors. Clean the fuel lines and make sure the fuel pump is working powerfully.
• Engine Rebuild (if necessary): In severe cases, rebuilding the engine may be required. This involves replacing damaged pistons, rods, and bearings and machining the cylinders for a perfect fit.

Step 3: Adjustments and Testing

After repairs, we fine-tune the engine to optimise its performance. We test drive the vehicle to make sure the knocking sound is gone and everything operates smoothly.

How Much Does It Cost to Fix a Knocking Engine?

The cost of fixing engine knock in Perth depends on the underlying cause. Here’s a rough estimate:

Factors Influencing Repair Costs

1. Extent of Damage: The more severe the damage, the higher the repair costs will be.
2. Vehicle Make and Model: Luxury vehicles often incur higher parts and labour costs compared to standard models.
3. Labour Rates: Mechanics in Perth typically charge between $100 to $150 per hour. Depending on their experience and expertise.

At Perth Auto Mechanic, we provide transparent pricing and discuss all options with you before starting any work.

Do I Need a New Engine If It’s Knocking?

Not always. The severity of the problem dictates whether you need a repair or a replacement. For minor issues like fuel quality or spark plugs, repairs are straightforward. But if your engine has sustained significant damage (e.g., a cracked piston). A rebuild or replacement is the only solution.

What is the Most Common Cause of Engine Knock?

By far, the most frequent culprit is using the wrong octane fuel. Many cars require higher-octane fuel to prevent premature combustion. Always check your owner’s manual and fill up with the recommended fuel type to avoid this issue.

How to Prevent Engine Knocking

Prevention is always better than cure. Here’s how you can reduce the risk of your engine making a knocking noise.

1. Avoid letting your car idle for extended periods.
2. Clean your fuel system periodically to prevent carbon buildup.
3. Use the correct octane fuel as recommended by your car manufacturer.
4. Keep up with oil changes to ensure proper lubrication of engine components.
5. Schedule regular tune-ups to replace spark plugs and inspect ignition components.

Fix Engine Knocking Sounds Before It Gets Worse

When your car is making a knocking noise. You need expert hands to diagnose and fix the problem. At Perth Auto Mechanic, we combine years of experience with the latest diagnostic tools to deliver reliable solutions. Whether it’s a quick spark plug replacement or a complex engine rebuild. We fix everything.

Don’t wait for that knocking noise to get worse.

Call us today or visit our workshop to schedule a service.

We’ll get your engine running as good as new.

Fix My Knocking Engine