How to Find Exhaust Leak? Symptoms and Fixes

Sometimes, exhaust leaks are more than the loud, embarrassing, and annoying noise you hear when starting or driving your vehicle. It is very risky if the leaks are near your fuel lines or any flammable areas in your car, or if the exhaust is getting into your vehicle’s cabin. If the leaking area is big enough, it’ll affect your vehicle’s performance and change your vehicle’s backpressure. Aside from these, inhaling the fumes that come out during an exhaust leak is very dangerous to human health.

This is why it is crucial to know the symptoms of an exhaust leak, how to find exhaust leak, and fix the leak without going to a mechanic (if you’re a DIY enthusiast). Let’s briefly look at the symptoms of an exhaust leak.

Exhaust leak symptoms

The exhaust system of your vehicle is there for your health and safety. If your exhaust system leaks for any reason or gets damaged, it releases poisonous gas into your vehicle’s cabin. These gases affect the health of the driver and the passengers when they inhale the gas. It would be best if you visit your mechanic once you notice a leak from your exhaust system.

exhaust leak symptoms

Embarrassing Loud Noise: when you turn on your engine and hear embarrassing noise like tickling or puffing noise coming from your engine bay, it is an indication that you have an exhaust manifold gasket leak. The gasket is found between your exhaust manifold and the cylinder head. This noise can also come from the exhaust flange joint.

Strong Odor: When a leak occurs anywhere in your exhaust system, especially near your catalyst converter, you’ll notice a strong odor in the air. If the smell stays for long, it is definitely a carbon monoxide smelling from your exhaust system. It can be lethal, and you must avoid it at all costs as you cannot take chances with it. If you notice this smell while driving, ensure you wind down your glasses.

Decreased Fuel Efficiency: once an exhaust leak occurs close to the exhaust manifold, it will reduce your vehicle’s efficiency by 3 to 4 mpg. This is because the exhaust bypasses the O2 sensor that senses the outgoing and incoming oxygen in your exhaust system. As a result, your car consumes excess fuel. Ensure you inspect your exhaust once you notice decreased Fuel efficiency so as not to waste money on refilling your gas.

Raspy or Tickling Noise and Vibration: Once you notice exhaust leak sound like a raspy, tickling, tapping sound in your engine bay or under your vehicle when accelerating, it tells you to have an exhaust leak. No matter the amount of the leak, it can generate Vibration or noise because fumes can escape. However, major leaks can cause embarrassing noise and Vibration that affects your steering wheel. You also get to notice that the exhaust leak sound when accelerating becomes louder.

How to Find Exhaust Leak on a Car?

As soon as you confirm your exhaust leaks, the next thing is to find where the leak is coming from. This guide will clearly explain how to determine where the leak is coming from, using three simple methods.

how to find exhaust leak with smoke

Do visual inspection: Once you notice an exhaust leak on your vehicle, the first thing to consider is if you previously worked on your exhaust system or disconnect it in any way while working on other parts of your vehicle. If you did, you have to do a visual inspection around the areas you worked in. Cross-check the gaskets, joints, and check for cracks on the exhaust pipe.

Note: The exhaust system gets hot than any other component in your car. Do not place your fingers on the exhaust when it’s hot, as it can burn off your fingers.

Block the Exhaust Tailpipe with Rag: This method might sound new, but it works wonders. When your exhaust is leaking, you’re likely to find black smoke from exhaust on the leaking areas. Sometimes, you have a hard time nailing down where the exhaust leak is coming from.

Read on to see how I find exhaust leak easily using this method.

First, you have to lift your vehicle off the ground. Get your floor jack, or car lift, and raise your vehicle. Ensure you raise the car in a way you can easily go under it. In addition to the jack, support your vehicle with Jack stand on both the front and back sides.

The idea of raising your car is to get an overview of your exhaust system. That way, you can quickly inspect your exhaust system. Now, here is the trick, start your vehicle and allow it to idle. While your engine is idling, you’ll need an assistant to help cover the exhaust tailpipe with a rag. Ask an assistant to cover the exhaust tailpipe very well and hold it firm.

This will make the leak more appearing, so you can easily detect the exact leaking spot.

Inspect for cracks on the manifold, and examine the exhaust gasket between the cylinder head and the exhaust manifold.

Note: you’ll notice a small leak at the bottom of the muffler. That’s normal. The muffler has small holes on it to allow water to come out. So, don’t think these holes are not supposed to be there.

These holes are built to allow water to come out. If the water fails to rush out and stores in the muffler instead, it’ll cause the muffler to rust. While using this method, you have to take off the exhaust heat shield on the manifold so as to easily inspect the exhaust manifold and the flange joint, also known as the exhaust neck.

For a visual presentation on how to do this, watch this video.

Use Soapy water: This method explains how to find exhaust leak with soapy water in simple terms. What you need here is soapy water in a spray bottle and a leaf blower, an air compressor with gloves and tapes or anything that can send in the air into the exhaust system.

Socket your leaf blower into your exhaust tailpipe and ensure it stays firm. You can support it with a tape. Turn on your leaf blower or air compressor, whichever one you’re using. Get your spray bottle and spray the soapy water on the suspected areas.

If you’re asking or wondering how to find an exhaust manifold leak, this method is the option for you. If you notice bubbles on the areas you spray soapy water on, it’s an indication that your exhaust is leaking from that spot. However, you don’t have to stop spraying the soapy water when you notice bubbles on a single spot. Your exhaust is likely to be leaking from more than one spot. No amount of soapy water is too much, so don’t bother if you’re over spraying it.

How do you fix an exhaust leak at home?

I’ve successfully outlined the exhaust leak symptoms, and how to find exhaust leak using three simple methods.

Now what? Let’s look at how to fix exhaust leak at home using three simple methods.

Once you have determined where the leak is coming from, concentrate on that very spot.

I’d recommend three different products to carry out the fix – first, high temp exhaust patch, this works by pushing it into the cracked area and allowing it gum the leak as it hardens like steel. The second product is the muffler bandage, and you can wrap it around the leaking area. It steels off and gets hard like steel. The final product is the exhaust clamp, which goes over the leaking area and seals it off when you tighten the clamp.

These products will pretty cover everything you need to fix your exhaust at home. The other things you’re going to need are a mechanic tools box containing hand gloves, sandpapers, tapes, and a metal hand wire brush.

Once you figure out the right product for you, just go get it. You can find these products at your Google store. They’re very cheap and easy to use.

Speaking of fixing your exhaust leak at home, let’s dive in straight away. The first recommended product, high temp exhaust patch is commonly used seal leaks on the manifold and exhaust pipe. Before you apply this, you need to clean the leaking areas, to do that, grab your sandpaper and wire brush. Scratch the little metal or debris on the surface where you want to apply the exhaust temp patch. After cleaning the surface, get some alcohol, and wipe the surface. Ensure it’s free from any rust, dirt, or debris. That way, you’ll get a good banding surface.

If you used an air compressor or leaf blower in detecting the leak, flip it around and turn it on to suck out air from your exhaust system. While sucking out the air in your exhaust system, mix your temp exhaust patch, and apply it on the cleaned surface. This will help to seal the exhaust leak very well. However, if you don’t have an air blower, you can apply the patch just after cleaning up the surface.

Now, you have to allow it to dry, and this can take up to 2-24 hours. You can use a heat gun to dry it very fast. Whatever you do, do not start the engine until you’re done. Remove the leaf blower before starting your engine.

The last methods are carried out with exhaust clamp and/or exhaust bandage, respectively. These methods are mostly used on exhaust pipes. If you find a leak on your exhaust pipe, you can use your exhaust clamp and cover the leaking area and tighten it.

Or you can use the exhaust bandage, and wrap up the leaking areas. To do this, you have to ensure your exhaust is hot, turn on the engine and allow it to idle for 1-2 minutes.

As soon as your exhaust gets hot, grab the bandage and wrap it over the leaking areas. Ensure you wrap the bandage as flat as possible. Keep it nice and tight. Take your heat gun and run it back and forth.

For a visual presentation, watch this video

FAQs:

Can I drive with an Exhaust Manifold Leak?

Driving with exhaust leak manifold can affect your health as the carbon monoxide in the exhaust fumes is dangerous to human health. Aside from this, a leaking exhaust reduces fuel efficiency, thereby giving much workload to your engine, resulting in more gas consumption. It will help if you consider these before driving with an exhaust manifold leak.

What Does Exhaust Leak Smell like?

One of the common signs and symptoms of an exhaust leak is a strong smell around your car. This strong Odor can be quite discomforting. A leaking exhaust or failing catalyst converter smells like sulfur.

Will an Exhaust Leak Throw a Code?

If your exhaust system is not well-tightened, it’ll affect the reading of your O2 sensor. So, if your car’s computer is throwing a code that indicates a bad or failing catalyst converter, you should fix the exhaust leak and re-diagnose your car. There are possibilities that additional issues exist in your exhaust system. To avoid complicated issues, you’ve to fix your exhaust system first.

Can Exhaust Leak Cause Loss of Power?

Yes, if there’s any leak on your exhaust system, it will potentially cause loss of power. An exhaust leak can result in power reduction, poor acceleration, or fuel-efficiency.

What Does a Small Exhaust Leak Sound like?

Knowing how small an exhaust leak sound like will help you do an audible inspection on your exhaust. While your engine is running, listen closely for a distinct noise around your exhaust pipes, mufflers, and manifold for a tickling or puffing noise. If the leaks occur around your catalyst converter, the noise will sound more like a hum, buzz, or hotrod noise.

How Expensive is it to Fix an Exhaust Leak?

The cost of fixing an exhaust leak depends on many factors; the make, model, year of your car, how many cylinders your exhaust has, and where you want to repair it. Fixing an exhaust leak will take roughly 1-2 hours. Most dealership charges $70-$100 per hour. So you should expect to spend $140 – $200 for an exhaust leak service fee.

Final Words

You have seen the three methods on how to find exhaust leak, exhaust leak symptoms, and procedures on how to fix exhaust leak. With this article’s help and the visual presentations, I believe you are an expert by now.

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Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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