Rattling noises coming from your car when driving can send shivers down your spine. If your vehicle is making a rattling sound, there surely is an issue that needs to be dealt with. 

The first question that might arise in your mind is, “What can be the cause behind this sound?” 

Well, there are a number of factors that can contribute to the rattling noise of your vehicle, including 

  • Broken Heat Shield 
  • Valve Train Issue 
  • Worn Exhaust Components 
  • Transmission Problems 
  • Damaged Engine Mounts 

Keep on reading to find out the source of a car rattle when accelerating and how you can fix the problem. 

The Exhaust Components May be Loose

It is a good thing to rule out simple things before considering engine and transmission issues. A loose exhaust system can be one of the reasons why your car makes noise when accelerating. 
The rattling increases with speed, so you might not hear it at slow speeds, such as below 20mph. Acceleration transmits energy through the transmission system, causing a car to shake. As the car shakes, the loose exhaust system will bang on the body, causing rattling sounds. 

Other signs indicating that your exhaust system might not be securely attached include: 

  • Increased consumption of fuel 
  • Decreased performance 
  • A stench of exhaust gases 

Causes Behind Loose Exhaust Components

Some of the common causes behind loose exhaust include: 

  • Bad driving conditions 
  • Installing exhaust system improperly 
  • Harsh driving habits characterized by rough acceleration 

How to Fix the Rattle Caused by the Loose Exhaust System?

Inspect the exhaust system when the engine is running. If the exhaust is loose, listen for strange noises by grabbing the exhaust tip at the back and shaking it. 

If the exhaust system is the cause, you can fix it with blots and mounts, or you can engage an experienced mechanic to fix the issue. If your exhaust system is showing signs of leakage, you will have to get it fixed.

Damaged or Loose Engine Mounts 

Motor mounts are responsible for holding the engine and transmission to the car frame. These mounts secure your engine and transmission to the car frame and reduce the vibration and noise. These are made from metal and rubber, and if they are broken, there is nothing that can keep the engine from moving around. This will result in direct metal-on-metal contact, causing your vehicle to make a rattling noise when accelerating because of the added workload. 

Not fixing the issue right away can cause a lot of damage to your car, such as a broken exhaust manifold or drivetrain failure. 

A damaged engine mount shows signs, including: 

  • Oil leakage 
  • Engine vibration 
  • Misaligned wheels 
  • Excessive damage to engine parts 

How Do You Fix Damaged or Loose Engine Mounts?

The good thing is that it is quite easy to resolve the issue of damaged engine mounts. It is preferable if you do not crawl under your car to fix the problem yourself and hire a qualified technician to do the job. 

Damaged Heat Shield

The heat shields are metal parts that surround various parts of the exhaust system and keep your vehicle safe from the heat it puts out. These heat shields include: 

A thermos-protective barrier – Present between the exhaust system and other car parts

Heat shield in the engine bay area – Prevents heat damage to internal components and overall bodywork.  

The shield can be damaged due to cracks or rust, resulting in a rattling noise when driving.

Signs showing damage to heat shields include: 

  • An overheating engine
  • Excessive cabin heat
  • Decreased Performance 
  • A burning smell from the hood or car body 

Accelerating at this point can be nerve-wracking because you are unsure if it affects your vehicle’s safety and drivability. 

How to Fix Damaged Heat Shield?

The easiest way to fix a damaged heat shield is to inspect the vehicle and get it replaced. In the future, consider insuring your vehicle from heat, dust, and sound. 

Some of the common causes of damage to your heat shield include:

  • Corrosion from rust 
  • Impact of collision accident 
  • Normal wear and tear

You should replace a damaged heat shield as soon as you can to reduce the risk of accidents and fires. 

Transmission Issue 

Another reason behind your car making a rattling sound is if the transmission fluid gets low and the engine does not receive enough lubrication.

The transmission fluid makes a thin layer between the moving parts so they do not run against each other.  Without enough oil, the car will start to rattle while accelerating. Not fixing this issue can lead to costly repairs. Without enough lubrication, the metal grinds tons of meat and causes the gears to wear down, and in the end, you will have to rebuild or replace the transmission. 

Signs of low transmission include: 

  • The car starts to jerk as it speeds 
  • Transmission slips 
  • Difficulty in changing gears 
  • Bad driving habits
  • Poor car maintenance  
  • Leaks in transmission 

How Do You Fix Transmission Issues in the Car?

Fixing rattling sound caused by transmission issues is quite easy. Some of the steps you can follow to prevent your gears from overheating include: 

  • Check your transmission fluid levels. If the fluid is low, refill it with transmission oil. 
  • Make sure to service your transmission regularly. 

Worn-Out Suspension Parts 

The suspension system plays a vital role in controlling the motion of the car. It connects the vehicle body to the wheel through struts, stabilizers, rods, links, and bushings. Besides the rattles, other signs indicating a damaged suspension system include 

  • Uneven tire wear 
  • Excessive vibration 
  • A bouncy ride
  • Leaning on one side

Causes Behind Suspension Wear and Tear 

The possible causes behind suspension wear and tear include 

  • Overloading 
  • Harsh driving 
  • Poor maintenance  

How to Fix Worn-Out Suspension Parts? 

In order to fix the worn-out suspension system, get it checked by a qualified mechanic. One of the reasons why you shouldn’t do it yourself is because suspension parts are present at hard-to-reach places, and some suspension wear may not be visible to the untrained eye. 

Preventive Maintenance 

Some of the ways you can prevent the rattling sound when accelerating at low speed or high speed include regularly inspecting your car can assist you in identifying the potential issue before it escalates. This includes checking the engine mounts, heat shields, transmission fluid levels, and suspension parts. By getting your car checked regularly and addressing these minor issues, you can prevent significant problems and costly repairs from occurring in the future. 

When to Do it Yourself (DIY)?

Tasks including replacing air filters, changing the oil, or tightening the loose components can be easily done at home and require basic knowledge. DIY can help you save labor costs, and doing minor repairs on your own can also help you know more about your vehicle. 

When to Consult a Professional?

If your car is dealing with complex issues, such as issues related to the electrical systems, transmission, or engine internals, it is preferable to get assistance from a professional. This is because if you do not have expert knowledge, some repairs might not be done correctly, which can compromise the vehicle’s safety. Therefore, it is crucial to recognize when the issue is beyond your skills.

Lastly, DIY repairs can affect the car’s warranty. Therefore, always check the warranty terms before attempting to do any repair on your own.

Final Thoughts 

A car making a rattling sound when driving can be a sign of serious issues. Ignoring the sound can put your vehicle and life at risk as some of the rattles can be linked to serious mechanical issues.

Always check your car and get it checked by a qualified technician, and also address the cause of rattling immediately before the issue becomes serious.