If your exhaust is blowing a gale—sounding like a Spitfire or an old crop-sprayer—it’s usually down to a hole that’s developed due to corrosion or decay over time, or where two pieces of the system have separated at their joint.

As well as loud, thundering noises, other tell-tale sounds of an ailing exhaust are hissing (cracks or leaks), chugging (blockages), and rattling (the exhaust is loose or misaligned).

What causes an exhaust to be loud?

Several components in your exhaust can wear out over time, work loose, or even come away from their fixings. Where your exhaust system isn’t airtight and properly sealed, the gases escaping from those holes, leaks or corroded areas can be incredibly loud.

Fixter has exhaust specialists ready and waiting to pinpoint your problem, replace faulty components, and get you back to the peaceful motoring you’re used to. 

What are the common causes of a loud exhaust?

A corroded silencer/tailpipe/back box

Risk level – Low

What to do – Have it replaced as soon as possible.

The first part of the exhaust system to go faulty, developing corrosion and holes, is usually the silencer. It’s the final piece in the system, and being the furthest from the engine, it stays relatively cold, allowing gases to condense into liquids. These liquids can cause corrosion, as can the rain and snow thrown up from the road.

Modern exhaust materials, such as stainless steel, extend silencer life years beyond the earlier, more traditional materials, but wear and tear can still show its toll over time.

Damage from debris, road features or poor driving conditions

Risk level – Low

What to do Repair or replace any faulty parts or connections.

Exhaust damage can happen when driving too fast over sleeping policemen, potholes, low bridges, or other hazards our daily drive can produce. It could also be from debris thrown up from the road into the underneath of your car, causing damage to your exhaust.

Leaking from exhaust section connections

Risk level – Medium

What to do – Check and seal all joints.

The joints between each component and the fixings that fasten them to the vehicle body can work loose or corrode over time. If any of them fail to do the job properly, then the connections won’t offer the snug fit needed, and start leaking exhaust fumes; the bigger the problem—the louder the noise.

These are often relatively easy fixes, but given exhausts are often difficult to access, it could still be to your advantage to have a mechanic carry out the work.

Your catalytic converter is faulty or missing

Risk level – Low

What to do Repair or replace the faulty cat.

A faulty catalytic converter can cause some pretty noticeable vibrations and a somewhat clunky rattle when you’re idling in stationary traffic.

Stealing catalytic converters became quite a trend, and in some areas, more popular than alloy wheels, leaving those cars up on bricks. Your cat contains several precious metals, so they fetch a good price with many scrap merchants and auto-breakers. If your catalytic converter gets stolen—and that section of the exhaust missing—your exhaust will blow as loud as ever when starting the car.

How do you fix a loud exhaust?

It all depends on the size of the hole and the repair required. Small holes can be sealed with exhaust putty and specially designed patches. Broken joints, seals and fixings can be replaced simply enough, and usually at a low cost.

If a faulty section is beyond repair, then there’s nothing else you can do other than replace it.

Is it safe to drive with a noisy exhaust?

It’s not too detrimental to your car’s health if the hole or leak is relatively small, but bigger holes and severe blowing can affect the backpressure into your engine. Any engine performance issue can affect your car’s health if left for extended periods, so it’s vital to remedy any leaks as they appear.

Another important point to note is that exhausts don’t only keep the noise down but remove poisonous gases and emissions safely away from your car. If there is a leak, carbon monoxide could be entering your car’s cabin, which has no distinctive smell. With that in mind, wind down the windows and make sure there’s a steady stream of fresh air for you and your passengers if there’s excessive noise coming from your exhaust.

Why does my car sound louder than usual?

If your car only sounds a little louder than it usually does, it could be the start of a bigger problem with a small, hard to spot leak blowing or a tiny crack between connections. Have the full exhaust tested to detect the problem. Catching the issue early could save you a lot of money in the long run.

How much does it cost to fix a loud exhaust?

According to our data, a complete exhaust replacement should cost between £300 and £600 depending on your car’s size, make, and model. High-performance vehicles and sports cars can cost even more.

Can you drive with a noisy exhaust?

There are fines for driving with ‘too loud’ exhausts, with motorists liable to a fixed-fee penalty of £50 for cars exceeding 74 decibels. These fines are generally aimed at modified exhaust systems designed for louder performance. A faulty yet noisy exhaust will usually be overlooked as long as you’ve taken the correct steps to have the fault fixed.

If part of your exhaust system is blowing a gale or making far more noise than it should, Fixter can sort it out. We’ve got exhaust specialists near where you live, ready to examine your complete system and diagnose the problem. Once we’ve tracked down the fault, we’ll run you through the solutions, the costs and soon have your car running quietly enough for you to be able to hear yourself think again.

About Fixter

Fixter is revolutionising the car maintenance industry, one repair at a time. Fixter was founded to make car maintenance as easy as booking a taxi. Digital, transparent and stress-free, with world-class customer service. Since launching in Manchester in 2017, Fixter has expanded to more than 100 towns and cities across the UK and provided thousands of car owners with honest, convenient and affordable car repair services.