5 Symptoms of an Exhaust Leak (That You Shouldn't Ignore) (2024)

Hearing annoying noises from under the car? Vibrating gas pedal? An exhaust leak could be the culprit. Exhaust leaks may allow harmful gases into the cabin while reducing engine performance and fuel economy.

In this article, we’ll cover five key symptoms of an exhaust leak and whether or not it’s safe to continue driving until you get the leak repaired.

Common Exhaust Leak Symptoms

Below five of the most common symptoms of leak in your exhaust system:

#1 – Noise That Gets Louder

When you start your car, pay attention to the sounds coming from the engine area. If you hear a noise that gradually gets louder as the engine runs, it’s often a clear sign of an exhaust manifold gasket leak.

The gasket, which seals the connection between the exhaust manifold piping and the engine block, experiences the same heating and cooling cycles as the pipes. If you can’t spot any visible cracks or leaks in the piping, take a closer look at the gasket for any signs of damage or wear.

See Also: 5 Ways to Make Your Exhaust LOUDER

#2 – Vibrating Gas Pedal

Even a tiny exhaust leak can cause your car to vibrate. The bigger the leak, the more noticeable the vibrations will be.

You’ll typically first feel these vibrations through the gas pedal. If the issue isn’t addressed, the vibrations will eventually reach the steering wheel. In severe cases, you may even feel the floorboards shaking.

#3 – Bad Fuel Efficiency

Keep an eye on your fuel consumption. If you notice that your car is suddenly requiring more gas than it typically does to travel the same distances, a leaky exhaust system could be the culprit.

Exhaust leaks force your engine to work harder to maintain performance, which in turn reduces your fuel efficiency. If you’re filling up more often than usual, it’s worth investigating a potential exhaust leak.

#4 – Unusual Noise When Accelerating

When you press down on the gas pedal, pay attention to any noises that don’t seem right. If you hear sounds that resemble air leaking out or a whistling sound, it’s an indication of a possible exhaust problem.

However, it can be difficult for the average person to distinguish between various engine sounds, exhaust noises, and even a vacuum hose leak. Additionally, strange engine noises can be caused by a variety of other engine problems.

Only consider this symptom as confirmation if you’ve already noticed another sign of an exhaust leak and want to verify your suspicions.

Read Also: Pros/Cons of a Resonator Delete

#5 – Unusual Odor

While carbon monoxide itself is odorless, not all exhaust fumes lack a scent. If you have a leaky exhaust manifold, you’ll likely notice a strong, unpleasant odor either inside or outside your vehicle. If this smell persists, it’s a clear indication that you’re being exposed to harmful exhaust fumes that you shouldn’t inhale for an extended period.

If you suspect an exhaust leak based on a strong odor, take your vehicle to a repair shop as soon as possible. Have them diagnose the problem and repair it promptly. In the meantime, drive with your windows open to minimize your exposure to dangerous fumes.

Don’t take any risks with carbon monoxide, as it can be fatal in high concentrations.

Read Also: What If Your Engine Oil Smells Like Gas?

#6 – Check Engine Light

Your car’s exhaust system has O2 sensors that monitor its performance. If there’s a leak, these sensors may detect it and trigger the check engine light on your dashboard.

However, keep in mind that the check engine light can come on for many reasons, not just exhaust leaks. It’s best to use an OBD-II scanner to read the diagnostic trouble codes (DTCs) and pinpoint the exact issue.

#7 – Reduced Engine Performance

An exhaust leak can negatively impact your engine’s performance. You might notice a loss of power, particularly during acceleration, or a rough idle.

This happens because the leak allows exhaust gases to escape before they pass through the catalytic converter and muffler. The result is reduced back pressure, which can confuse your car’s oxygen sensors and throw off the air-fuel mixture.

If your car feels sluggish or struggles to maintain speed, especially in combination with other symptoms on this list, an exhaust leak could be the reason.

Can You Drive With an Exhaust Leak?

While it’s possible, you should not continue driving your vehicle knowing it has an exhaust leak. While extra noise, vibrations, and poor gas mileage might just be annoyances, carbon monoxide is no joke.

You may think that you’re protected inside the car’s cabin from noxious exhaust fumes, but in reality, the inside is not airtight so carbon monoxide can slowly start seeping in but it has a hard time getting out.

See Also: Oil Coming Out of Your Exhaust? (What it Means)

Some exposure to exhaust fumes can cause headaches, fatigue, or dizziness which can easily cause an accident. Prolonged exposure to carbon monoxide can even lead to death.

If you feel like you’re experiencing any of the symptoms above (especially if you also smell exhaust fumes in the cabin), you should really take your car (with a window rolled down) to an auto repair or muffler shop right away.

Related: Does a Car Need a Muffler and Resonator?

Common Exhaust Leak Causes

Several factors can lead to exhaust leaks. Understanding these causes can help you identify potential issues before they worsen and lead to costly repairs.

Corrosion

Over time, exposure to moisture, salt, and other environmental factors can cause exhaust components to rust or deteriorate. This is especially true for vehicles in coastal areas or regions that use road salt in the winter.

But rust on your exhaust components is preventable. Rinsing the underside of your vehicle (a couple times a month) is a good way to remove corrosive materials like salt that cause damage. But make sure all components have cooled down before spraying cold water on them.

For longer term solutions, your exhaust system can be painted with high-temp paint or even powder coated. An aftermarket stainless steel exhaust system is another way to go. In addition to better rust protection, aftermarket exhausts can look better, sound better, and improved performance.

Damage

Damage from road debris or accidents can also cause exhaust leaks. Rocks, sticks, and other objects can strike the underside of your vehicle and puncture or dent exhaust components.

Accidentally running over a curb with a low clearance car is another way damage can lead to leaks. Minor fender benders can also shift or crush exhaust pipes and mufflers.

Loose or broken exhaust mounting hardware is another way damage can occur. Exhaust systems are secured to the underside of the vehicle with a series of clamps, hangers, and brackets. If these components loosen or break due to age or stress, it can cause the exhaust pipes to sag or rattle, leading to leaks at connection points.

Faulty Repairs or Modifications

If a previous repair was done incorrectly or with subpar materials, it may fail prematurely and lead to an exhaust leak developing. Similarly, aftermarket exhaust modifications like headers or oversized mufflers can put additional strain on the system if not installed properly.

Repair Options and Costs

So you’ve determined that you have an exhaust leak. Now what?

The first step is to locate the exact area of the leak and its severity to determine what your repair options are going to be.

For small holes or cracks, a temporary fix may involve using exhaust tape or sealant. These products are designed to withstand high temperatures and can be applied directly to the damaged area.

While this is the lowest-cost option, typically ranging from $10 to $50, it’s not a long-term solution and may only last a few months at best.

If the leak is caused by a damaged gasket, flange, or hanger, replacing the faulty component is often the best approach. Gaskets are relatively inexpensive, usually costing between $20 and $100, but labor costs can vary depending on the location and accessibility of the leak.

Flanges and hangers may cost more, ranging from $50 to $200 or more, depending on the vehicle and the specific part needed.

For more severe leaks or extensive damage, welding or replacing entire exhaust sections may be necessary. This is typically the most expensive repair option, as it involves more labor and larger replacement parts.

Costs can range from $200 to $1,000+, depending on the extent of the work and the make and model of your vehicle.

In some cases, particularly with older or high-mileage vehicles, it may be more cost-effective to replace the entire exhaust system rather than repairing individual components.

A complete exhaust system replacement can cost anywhere from $500 to $2,000 or more, depending on the vehicle and the quality of the replacement parts. But this also gives you an opportunity to upgrade your exhaust for better performance and sound if that sounds appealing.