Car Rattles When Accelerating: 8 Common Causes & How To Fix

Ever noticed that scary noise as your car rattles when accelerating? Does it annoy you? Don’t worry!  In this article, we’ll delve into why your car is generating that noise and provide a comprehensive, step-by-step guide to resolve this issue.

Common Reasons for Car Rattles

Here, we provide some common causes to help you understand clearly:

The heat shield is broken

A heat shield that’s broken or not attached properly is often the reason behind a rattling noise in cars. These important parts help to protect your car’s components from getting too hot.

The heat shield that’s around the catalytic converter is known for often getting loose or falling off. This can happen because the converter is located close to the ground.

Additionally, heat shields are also found around the car’s engine bay and exhaust manifold. If these shields aren’t working properly, you might find your car getting hotter than usual or even smelling like something is burning

The driveshaft is out of alignment

The driveshaft of your car is crucial for transferring engine power to the wheels. If it’s not aligned correctly, this can lead to a rattling sound when you accelerate. The uneven rotation of a misaligned driveshaft makes it bump into other parts as it spins.

To fix this, you’d usually need to visit a mechanic. They’ll inspect the driveshaft, and if it’s out of alignment, they’ll either realign or replace it.

Car driveshaft

Low transmission fluid

Transmission fluid supports your car’s transmission running smoothly. If there’s not enough, your transmission might make a rattling noise, particularly when the car speeds up. This happens because the transmission components aren’t getting enough lubrication, leading them to scrape against each other.

To tackle this problem, you’ll have to check and top up your transmission fluid if it’s low. But, if the rattling continues, it’s best to get a mechanic involved.

Bad motor mounts

Motor mounts are like cushioning buffers that hold your engine to the car’s structure and help dampen the impacts during your journey. If these motor mounts come loose, the engine will vibrate excessively, which could lead to damage to other parts of your vehicle.

You might feel an unusual vibration coming from the engine area while you’re on the road, accompanied by squeaks, rattling noises, or vibrations. Furthermore, faulty motor mounts can disrupt your car’s alignment, resulting in uneven tire wear.

Engine accessory problems

Sometimes, the source of that rattling sound isn’t an internal engine problem. It could be due to external engine parts, like the drive belt pulleys and tensioners, malfunctioning, which can cause a rattle or a squeal.

You can check for this by removing the drive belt and starting the engine, turning it gently. If the noise disappears, then the problem likely lies with one of these components. However, be cautious not to run your engine too long without the belt.

Car drive belt

Worn-out spark piston

A piston is yet another potential reason behind the rattling noises in your car. This phenomenon occurs when the piston hits or jostles against the wall of the engine cylinder.

If your vehicle has worn-down pistons, you might see the check engine light illuminate on your dashboard, witness a decline in engine performance, or notice your vehicle’s fuel efficiency isn’t as good as it used to be.

Loose exhaust system

Exhaust parts that are damaged or have become worn over time are commonly the cause of annoying rattling sounds in your vehicles. Given their low positioning in the car, the exhaust pipe and muffler are particularly prone to corrosion and potential harm from road debris.

Moreover, loose elements in the exhaust system can also be the reason behind these rattling sounds. Often, the issue can be traced back to a broken exhaust hanger – small pieces of rubber that occasionally snap or become unhooked.

The valve train issue

Valve train problems can also lead to that rattling noise. This typically happens when the intake and exhaust valves are worn out, or when there’s a problem with the hydraulic lifters.

Defective valves can cause the fuel in your car to burn too soon, creating a noise that’s reassembled glass bottles clinking together. Meanwhile, faulty hydraulic lifters can cause the engine valves to stick, leading to a clicking or knocking sound.

Car engine valve system

Car Rattles When Accelerating: Step-by-Step Guide

Now, if you are worried about the problem mentioned above, we will provide you with a detailed guide to help you solve it:

Fix the heat shield

Normally, the heat shield is an essential component designed to protect your car from the heat produced by the exhaust system. If your car has started rattling, it could be because the heat shield is damaged or loose. Here’s a simple guide to help you sort out this issue:

Step 1: Look over the heat shield

First, you need to find the heat shield. It’s generally found under your car, guarding the exhaust pipe. Be careful to look closely for any signs of wear and tear, like dents or rust spots.

Step 2: Secure loose bits

Next, if your heat shield is just a bit loose, tightening the clamps or bolts holding it in place might solve the problem. Be sure to wear gloves to protect your hands, and always use the right tools to avoid getting hurt.

Step 3: Consider replacement

Finally, if the heat shield is badly damaged or covered in rust, it’ll need to be replaced. It’s better to have a professional mechanic do this job to make sure it’s done properly.

Tight motor mounts

Moreover, if these mounts are loose or worn down, you can consider checking your motor mount, which can cause your car to rattle. Here’s a simple way to handle this issue:

Step 1: Inspect the motor mounts

You should locate the motor mounts first, you can find them on either side of the engine. When you found, check for any signs of wear and tear or looseness.

Step 2: Tighten the mounts

Well, if the mounts are loose but not worn out, you may be able to simply tighten the bolts. Make sure you have the right tools for this and always be cautious around the engine.

Step 3: Replace if necessary

And If the motor mounts are worn out or damaged, they’ll need to be replaced. This can be a complex job and it’s recommended to have a professional mechanic handle it.

Adjust the driveshaft

Lastly, the driveshaft is also a key part of your car that helps transfer engine power to the wheels. If it’s not aligned properly, it can cause a rattling noise when you’re accelerating. Here’s how to handle this problem:

Step 1: Seek a professional mechanic

First thing before doing this task, you should seek a professional mechanic to help you check due to driveshaft issues can be complex.

Step 2: Adjust the driveshaft

If the mechanic finds that the driveshaft is out of alignment, they will adjust it to the correct position. This usually involves lifting the car and manually adjusting the driveshaft using specialized tools.

Step 3: Replacement might be necessary

If the driveshaft is too damaged or worn out, it may need to be replaced entirely. A professional mechanic should handle this to ensure the new driveshaft is properly installed and aligned.

Remember, when it comes to complex components like the driveshaft, it’s best to trust the professionals. Improper adjustments can lead to further issues down the line.

In summary, if you are not confident to do the above task, you need to consider taking your car to a professional mechanic to check and fix it.

Read more: Greenlander Tyre Review: 4 Must-know Key Features


A car that rattles when accelerating can cause frustration and worry. But by understanding the common causes and knowing how to fix them, you can drive with confidence and peace of mind.


  1. How can I stop my car from making a rattling sound when I speed up?

    Your car might make a rattling sound when you speed up for many reasons. These can include a shaky exhaust system, a worn-out suspension, a dry transmission, loose engine parts, or old heat shields. To fix the noise, you might need to change any parts that are not working right, make sure everything is tight, and refill any fluids that are running low.

  2. Could a low oil level result in a rattling sound?

    A well-lubricated engine with fresh oil should operate relatively quietly. However, as the oil gets older and loses its ability to lubricate the engine components, these parts will start to interact more harshly with each other, causing friction and grinding. This will likely result in noises such as rattling, rumbling, and knocking, which will be difficult to ignore.

  3. What could be causing my car to rattle when I exceed 60 mph?

    If you notice your car vibrating every time you hit speeds between 50 and 70 mph, the most probable cause is unbalanced wheels. The vibrations can typically be felt starting from the steering wheel, spreading across the seats, and through the floor of the vehicle.

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