9 Reasons Your Car Rattles When Accelerating
Does your car make a rattling noise when accelerating? If so, you are by no means alone. Complaints about rattling noises from a variety of sources are among the most common car troubles.
Often, identifying the cause of such a rattling noise is more difficult than actually repairing it. Here are the main causes of a rattling noise when accelerating: Where does the rattle noise come from? Rattling noises can come from almost any area of the vehicle, and many of these noises vary greatly in pitch and intensity. The key to troubleshooting this type of noise is identifying its source so it can be investigated further.
The causes of vehicle rattles can easily be broken down into a few different categories. These categories include underbody rattles, wheel well rattles, under hood rattles, interior rattles, etc. Categorizing your vehicle noises as described can help you focus your diagnostic efforts.
Rattling noises under the car
It is very common to experience rattling noises under your vehicle. Most of these noises can be attributed to exhaust issues. This type of noise is most noticeable when the vehicle’s engine is under load or during acceleration.
1) Loose exhaust brackets and clamps
Over time, exhaust system brackets and clamps tend to deteriorate, mainly due to corrosion. When this happens, these vital components can become loose or rot until they fail.
The result can be excessive vibration, which often results in noises of varying intensity under acceleration. Fixing this type of problem will usually require component replacement. Damaged hangers should be replaced with OEM equivalents if necessary, as should rusted or damaged exhaust clamps.
2) Faulty catalytic converter
Today’s vehicles use catalytic converters to break down common pollutants in exhaust gases and convert them into less toxic chemicals.
Unfortunately, these devices can fail due to overheating or impact, causing parts of their internal structure to break off and rattle. This sound often sounds like marbles shaking in a can.
If your catalytic converter fails, it will need to be replaced. However, catalytic converters usually work just fine unless they are damaged by an underlying factor. Before replacing the device, the root cause of this damage must be diagnosed.
3) Heat Shield Damage
A vehicle’s exhaust system is typically covered with numerous heat shields that protect other components from the effects of thermal radiation. Heat shields are relatively problem-free, but are susceptible to rust and corrosion. In these cases, the heat shields can peel off from their welds and cause vibrations to nearby exhaust components.
If the heat shield begins to peel off from its mount, it can be stapled back in place or replaced and reinstalled. Typically, replacement is required when rust has completely compromised the integrity of the heat shield.
Wheel Arch Rattles
Most often, rattling noises can come from the front end or wheel arches of the vehicle. In most cases, this is due to worn or damaged braking, steering, or suspension components. In most cases, a thorough visual inspection is required to determine the root cause of such noises.
4) Improperly Installed Brake Components
When a car or truck comes to a stop, the vehicle’s braking components are subjected to a lot of force. For this reason, individual components have a tendency to shift out of place if they are not relatively securely fastened. Brake rattle is a frequent occurrence if one or more brake pads do not have anti-rattle clips installed.
If you suspect that your brakes are making any unusual noises, they should be inspected immediately. If you are not confident in diagnosing such issues yourself, seek professional advice.
5) Loose or damaged steering/suspension components
Vehicles rely on steering and suspension components to provide good handling and a satisfactory level of ride comfort. However, these components can and do deteriorate over time, causing a variety of wear-related problems.
Bushings can wear out, shocks and struts can fail, and bushings on the ends of linkages can develop play. Additionally, impact damage of any kind can cause similar problems.
Diagnosing failures of individual steering and suspension components requires performing a thorough inspection. Often, pressure must be applied to each component to accurately check for play. Rattling noises under the hood
Rattling noises can come from the engine compartment of a vehicle and cause serious problems. The causes of these noises can be very different and vary in severity. A hood lock could be the cause. Any irregular engine noises should be investigated immediately to avoid further issues.
6) Engine ancillary problems
Many people fear the worst when their car engine makes strange noises, but the actual problem is often much less serious than they think. Often times, these noises are caused by engine accessories and not an actual internal engine issue.
Bearings on all belt-driven components are prone to failure, causing a variety of noises, including rattles. Loose mounts are also a common cause of engine rattles.
If you suspect that the rattle noise is coming from your car’s engine compartment, it’s important to identify the location of the problem component.
This can often be difficult, but there are some steps you can take to make the search easier. First, make sure all brackets attached to the engine are securely fastened.
If you suspect a belt-driven accessory may be the cause, remove the belt, start the vehicle, and rev the engine slightly. This will help determine if the noise is still there.
However, because your vehicle’s drive belts support the function of vital engine components such as the water pump and alternator, this test should only be performed for a few seconds.
7) Internal Engine Issues
While rare in relation to alternative sources of noise, internal engine issues can indeed produce a rattling sound. The three main culprits of the internal engine-related rattle are piston slap, rod knock, and lifter related issues, which all produce a distinct noise.
1. Piston slap tends to sound like a muffled, metallic rattling noise that changes in frequency with engine speed.
2. Rod knock produces an unmistakable metal-on-metal clatter, that slows in frequency at low speeds.
3. Lifter related noises are most commonly described as a “ticking” which also mirrors the speed of an engine.
Each of the aforementioned issues are typically expensive to remedy, and often require extensive internal engine work or an engine overhaul. If any such sound is heard and is believed to be coming from your vehicle’s engine bay, pull over at the first available opportunity, and shut off your ignition.
Interior Rattling Sounds
One of the most common, yet least concerning of all rattles, are those that originate inside of your vehicle’s cabin. While these noises are certainly aggravating, they are seldom serious in nature. Interior rattles can often be remedied in minutes, with little necessary effort, by simply tracking down the source of such noises by ear.
8) Loose Trim or Compartments
In many cases, an interior rattle is caused by little more than a loose piece of interior trim, or an ill-fitting glove compartment door. As a motorist accelerates their vehicle, these loosened components begin to vibrate ever more quickly, producing an audible noise.
Locating the root cause of an interior rattle is generally no more difficult than placing hand pressure on various components within the vehicle’s cabin. While doing so, listen for the offending rattle to be stifled.
Kick panel trim, doors (latch assembly, lock cylinder, window regulator, etc.), dash bezels, glove compartment doors, and center console lids are all common sources of rattles.
9) Loose Change or Other Small Items
Another common cause of interior rattles is the vibration of spare change and other small items within a vehicle’s cup holder or ashtray. Such items are often forgotten within a vehicle’s interior, only to be remembered when traveling down the road.
These noises can be alleviated by simply removing the offending change, or any other loose items that are rattling about. The future occurrence of such noises can also be prevented by emptying all cup holders, ashtrays, and change receptacles on a weekly basis.
