Why is my Subaru Impreza loud?

In most cases, a louder-than-usual Impreza comes from the exhaust system (such as a leak, damaged muffler, or loose heat shield). Other common sources include tire or wind noise, or engine-related issues that become noticeable as the engine or RPM changes. If the noise is sudden, persistent, or accompanied by a smell of exhaust or warning lights, have the car inspected promptly.

Common causes of loudness

The noise can originate either from the exhaust path or from non-exhaust components. The following lists break down where problems most often arise.

Exhaust and undercarriage issues

The following exhaust-related problems commonly produce a louder ride or a distinctive rattling or whine from under the car.

• Exhaust leaks at joints, holes in pipes, or gasket failure


• Damaged or deteriorated muffler or resonator


• Loose or missing exhaust hangers allowing the exhaust to rattle or hang lower


• Loose heat shields vibrating or banging against the exhaust or underbody


• Aftermarket exhaust systems or modifications that are louder than stock


• Catalytic converter issues (internal damage or clog) causing louder exhaust pulse or rattle


• Cracked or leaking exhaust manifold or manifold gasket (usually noticeable at idle or cold start)

Regular inspection of the undercarriage and a quick test drive can help identify these issues, especially if the noise seems to come from beneath the vehicle.

Non-exhaust sources

Noise that isn’t directly from the exhaust can still seem loud if other systems or conditions are contributing. Consider these possibilities.

• Tire noise from tread pattern, wear, improper inflation, or aggressive summer tires


• Wind noise around mirrors, roof racks, or sunroof at highway speeds


• Suspension components or wheel bearings that are worn or loose


• Engine-related sounds such as valve train rattle, vacuum leaks, or misfires that change with RPM

Determining whether the sound is purely exhaust, or influenced by tires or wind, can help narrow the search quickly. If you’re unsure, a professional inspection is advised.

How to diagnose

Use these steps to narrow down the source of the noise before visiting a shop.

• Note when the noise occurs: at idle, during acceleration, or at constant speed. If it changes with RPM, the source is more likely engine-related or exhaust-related.


• Check for exhaust leaks visually and by feel: look for soot around joints, bubbling when sprayed with soapy water at a crack (careful with a running engine), or a louder hiss at the source.


• Inspect for loose heat shields or rattling components under the car or around the catalytic converter area.


• Assess tire condition and road noise: inspect tread wear, tire pressure, and check if a particular speed or road surface makes the noise more obvious.


• Listen for other symptoms: misfire indicators (rough idle, stumble), check engine light, or unusual smells that could point to engine or exhaust issues.


• Check for aftermarket modifications: if an aftermarket exhaust or components were installed, noise levels may be higher; verify clamps and hangers are secure.

Proper diagnosis often requires a hands-on inspection and, if needed, a diagnostic scan to read any trouble codes that might relate to engine or sensor problems.

When to seek professional help

Consider professional help if the noise is new, persistent, or accompanied by warning lights, fumes in the cabin, or a noticeable drop in performance. Sudden loudness with a potential exhaust leak can allow CO to enter the cabin, which is dangerous.

What to expect from a shop

When you bring your Impreza in, a technician will typically perform the following checks to locate the source of the noise.

• Visual and physical inspection of the exhaust system, heat shields, and undercarriage for leaks or damage


• Diagnostic scan for engine codes and misfire indications


• Smoke or pressure test to locate exhaust leaks and check for vacuum leaks


• Inspection of tires, suspension components, and wheel bearings for wear or looseness


• Noise diagnostic drive to reproduce the condition and pinpoint the source

Depending on findings, the shop may repair exhaust leaks, replace a damaged muffler or shield, tighten or replace hangers, balance or rotate tires, or address engine-related causes if a diagnostic code is present.

Prevention and maintenance tips

Preventing excessive noise relies on routine maintenance and timely fixes for wear or damage.

• Inspect the exhaust system during regular service intervals and fix leaks or damaged shields promptly


• Keep tires properly inflated and replace worn or noisy tires to reduce road noise


• Avoid aftermarket exhausts that exceed stock noise levels if quiet operation is desired


• Address engine wear components (plugs, coils, vacuum hoses) to prevent misfire-related noise


• Have heat shields and exhaust hangers inspected and replaced if they become loose or corroded

Proactive checks can prevent loudness from becoming a persistent, costly issue and help maintain cabin comfort and safety.

Summary

Loudness in a Subaru Impreza is most often tied to the exhaust system—leaks, damaged mufflers, and loose shields being the primary culprits. Non-exhaust causes like tire noise, wind, and certain engine or suspension issues also contribute. Start with a careful inspection of the exhaust path and undercarriage, verify tire conditions, and consider a diagnostic scan if the noise coincides with engine activity. When in doubt, a qualified technician can pinpoint the source and recommend appropriate repairs to restore a quieter, safer drive.

Why is my Subaru Impreza so loud?

Your Subaru Impreza may be loud due to the natural sound of its boxer engine, but loud noise can also signal problems like a failing muffler, worn wheel bearings, or other exhaust issues. The engine's flat design causes a unique tone, and the car may also have less sound-deadening material than some luxury vehicles, leading to more noticeable road and tire noise. 
Common causes for a loud Subaru Impreza

• Boxer engine noise: The horizontally opposed "boxer" engine has a distinctive sound that is normal and not harmful. 
• Exhaust system issues: A louder-than-normal engine sound could indicate a problem with your exhaust system. This can be caused by a hole in the muffler, a loose hanger, or a failing catalytic converter. 
• Worn wheel bearings: A humming or "airplane-like" noise, especially at higher speeds, can point to worn wheel bearings. 
• Less sound deadening: Subaru vehicles are known to have more noticeable cabin noise due to less sound-deadening material and harder plastics in the interior, which can make road and tire noise more apparent. 
• Other engine or drivetrain issues: Other potential causes include a loose or worn serpentine belt, low oil pressure, or a failing CV joint. 

What you can do

• Listen to the noise: Try to identify the type of sound and when it occurs. A rumbling noise is often an exhaust issue, while a high-pitched hum at highway speeds could be wheel bearings. 
• Inspect the vehicle: Visually check the exhaust system for rust or holes. If you can safely lift the car, check for any play in the wheels or tears in the CV joint boots. 
• Consult a professional: A mechanic can accurately diagnose the issue. They can perform a full inspection of your exhaust, wheel bearings, and other components to find the source of the excessive noise. 

Are Subarus supposed to be loud?

Whether you drive a Crosstrek, Outback, Legacy, or WRX, Subaru's engineering is built for quiet strength. So if you hear something unusual, trust your instincts.

Why is my car suddenly so loud?

A car can suddenly become loud due to issues with the exhaust system (like a hole in the muffler or a leak) or internal engine problems (like worn-out parts, low oil, or bad spark plugs). Other possibilities include loose or worn belts, faulty engine mounts, or a problem with a catalytic converter. 
Exhaust system problems

• Holes or leaks: Rust or damage from road debris can create holes in the pipes or muffler, making the car sound much louder, especially when accelerating. 
• Damaged muffler: If the internal baffles in the muffler break down, it loses its ability to quiet the engine noise. 
• Faulty catalytic converter: A damaged or clogged catalytic converter can cause rattling or loud exhaust sounds. 

Engine problems

• Low or dirty oil: Insufficient lubrication can cause internal parts to grind against each other, leading to knocking or rough-sounding noises. 
• Worn spark plugs: Bad spark plugs can cause the engine to misfire, resulting in a louder sound or knocking noise. 
• Worn bearings: Worn-out engine bearings can cause a persistent knocking sound. 
• Engine mounts: If engine mounts wear out or break, the engine can shift more than usual, causing vibration and noise. 

Other issues

• Loose or worn belts: A worn or improperly tensioned belt can create a squealing or whining sound.
• Air intake issues: Problems with the air intake system can cause unusual noises. 

This video demonstrates how to diagnose engine noises: 1mBudget MechanicYouTube · Mar 14, 2021
What to do

• Listen carefully: Try to pinpoint where the noise is coming from (e.g., under the car, from the front hood) and when it happens (e.g., during acceleration). 
• Check your oil: Ensure the engine oil is at the correct level and clean. 
• Check the Check Engine light: If it's on, it can provide more specific diagnostic information and should be checked with a scanner. 
• Visit a mechanic: If you are unsure of the cause or if the noise is concerning, it is best to have a professional inspect the vehicle, especially if it sounds like metal-on-metal grinding or knocking. 

How to make a Subaru Impreza quieter?

You can reduce it by adding more noise insulating materials between the noise generating parts and your ears. Things like thicker carpet, mass loaded vinyl, undercoating of the entire vehicle, and better tires will all help to an extent, but it'll never be the same as a more luxury-focused product.