Will Rod Knock Cause Check Engine Light, vehicle check engine light

Will Rod Knock Cause Check Engine Light

There was a rod knock on my car. The knocking sound was very slight. So, I don’t mind it much, and I hoped to repair it after a few weeks. One sunny day, as I was driving home, the gentle knocking suddenly grew louder and more persistent. At the same time, the check engine light also came on. At that moment, my heart raced, and I felt a sense of panic.

Then I questioned myself: will rod knock cause check engine light to come on?

A rod knock itself does not directly trigger the check engine light. However, if the knocking sound becomes severe, it can cause engine damage or affect other components. This leads to abnormal sensor readings and triggers the check engine light.

So, I did thorough research to find out how rod knock causes the check engine light and how to prevent it in the future.

What is Rod Knock?

When the connecting rod bearings in an internal combustion engine are worn down or damaged, they make a banging or tapping noise known as a “rod knock.” This kind of mechanical problem frequently results from inadequate lubrication or severe wear.

What Are the Symptoms of Rod Knock?

Here is a summary of the symptoms of rod knock. Look! What are the things you experienced?

Knocking NoiseA distinct knocking sound from the engine
Increased VibrationVibrations felt throughout the vehicle
Loss of PowerEngine performance is reduced
Low Oil PressureThe oil pressure gauge reading is low
OverheatingEngine temperature may rise

What is Check Engine Light?

A car’s check engine light (CEL) is a feature of the onboard diagnostics system (OBD-II), which keeps an eye out for problems with various parts and systems. The CEL is lit to inform the driver of any faults that may affect the engine’s emissions or performance.

Will Rod Knock Cause Check Engine Light?

So, let’s come to our question. Will rod knock cause check engine light? In the event of a rod knock, the knocking noise is a sign that the engine has a significant mechanical issue. The vibrations and pressures from the banging can affect several engine parts, including the sensors in charge of spotting anomalies.

The engine control unit (ECU) may register a fault code as a result of these vibrations and strains, causing sensor readings to fall outside of their typical operating range.

Why Does the Check Engine Light Comes On Due to Rod Knock?

The check engine light turns on to alert the driver that there is a problem that needs to be attended to when the ECU discovers a fault code relating to the mechanical performance of the engine. While a rod knock itself might not set up the check engine light, the anomalous readings that result from sensors that are influenced by the banging may do so.

Is It Worth Fixing a Rod Knock?

It’s critical to deal with a rod knock as soon as possible. If left unattended, continuing operations with damaged connecting rod bearings might result in catastrophic engine failure. It is advised to get your car checked out and fixed by a licensed mechanic as soon as you hear a rod knocking noise or notice the check engine light is on.

How to Prevent Rod Knock Issues in the Future?

Here are 6 main tips to prevent you from facing a rod knock in your car:

Tip 6: Use the Correct Oil Viscosity

Follow the manufacturer’s instructions while changing the oil and filters. As a result, the lubrication system remains efficient and clean

Tip 5: Maintain Good Oil Pressure

Monitor oil pressure. Address any sudden drops or warning lights indicating low oil pressure promptly.

Tip 4: Practice Regular Engine Maintenance

Follow the maintenance schedule for tasks like timing belt replacement, valve inspection, and component checks. This prevents issues that could lead to rod knocks.

Tip 3: Address Engine Issues Promptly

Act quickly when experiencing abnormal sounds or performance issues. This prevents further damage and a potential rod knock.

Tip 2: Maintain Proper Oil Levels

Check the oil regularly and top up as needed to ensure proper lubrication, reducing rod knock risk.

Tip 1: Change Oil Regularly

Follow the manufacturer’s advice while changing the oil and filters.. This keeps the lubrication system clean and effective.


How long can a rod knock last?

The moment an engine starts to bang, the rod can suddenly snap. It might go on for a whole six months or until you restart it in your driveway. However, the engine will eventually break down, leaving you stranded.

Does rod knock get louder with RPM?

The truth is that as you drive the car, the rod knock sound becomes louder and more noticeable. The sound is a constant rattling noise that is particularly audible while the engine is speeding up. In contrast, when the engine is warmed up or running at higher RPMs, the sound caused by the piston slap will diminish and nearly go away.

If it is surely a rod knock sound, you can also hear it with an idle engine.

Does thicker oil fix rod knock?

Thicker oil won’t repair worn-out components. Nothing can be done to fix an engine knock brought on by excessive piston slap or crankshaft bearing clearances other than a mechanical fix.

Can a misfire sound like a rod knock?

Your spark plugs could start to misfire if they’re dirty or worn out. Since the plugs aren’t sparking properly and aren’t burning the fuel during each cycle, these misfires can result in unburned fuel in some cylinders. This may sound like a rod knock.


As you are currently experiencing rod knock, you may be wondering whether it will cause the check engine light to illuminate. You now understand the answer to the topic. Please be aware of the unusual sounds of the engine and fix them as soon as possible to protect your beloved car.

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