How Can I Fix My Exhaust Leak?

Fixing Exhaust leakExhaust leaks can range from very serious problems to an issue that seems to make your car or truck sound really cool and go faster.  In this article we will talk about your vehicle’s exhaust system, symptoms of a leak and what you can do about.

Your vehicle’s exhaust system serves a relatively simple purpose but sometimes accomplishes it in a complicated way.  The primary goal of your vehicle’s exhaust system is to direct the gases coming from your combustion chamber to a safe place.  The safest place is somewhere outside of your vehicle, far from you and any windows or openings in your vehicle which usually means somewhere under your rear bumper.  Your exhaust system’s secondary purpose is to muffle the sound of the explosions that are happening inside your engine as well as the sound of high velocity gases escaping from your tail pipe.  The complications come in when you look at the route that your exhaust will have to take and keep in mind that it can get to be extremely hot.  Lastly, your engine vibrates and moves around quite a bit while you are driving depending on whether you are accelerating heavily, down shifting or just idling.  So your exhaust has to safely carry dangerous fumes quickly and quietly to the back of your car without get anything too hot.

To accomplish this your exhaust system uses a variety of manifolds, heat shields, pipes, joints, flexible unions, mufflers and rubber hangers.  The extreme temperature swings – from ambient temperature to possibly over 1200 degrees – cause a lot of stress on all of these components.  Also, one of the byproducts of good combustion in your vehicle’s engine is water.  This water often exits your exhaust in vapor form but on cold days or short drives the inside of your exhaust system can be left wet, which causes the metal pipes and components to rust.  Lastly your exhaust system runs along the bottom of your vehicle so it is exposed to all of the elements from road dust and debris, to rain, salt snow and ice.

Your vehicle’s exhaust system lives a tough life so at some point in the life of your vehicle it will likely need to be replaced or repaired.  Some of the repairs on your exhaust system can be done yourself, while others should be left up to a professional.

Repairing your exhaust system starts with identifying where the problem is.  Finding the problem can be difficult since your exhaust pipe gets so hot.  You should never touch or handle any part of your exhaust system if your vehicle has been driven anytime in the last few hours!  Start with a visual inspection.  Pop your hood and find the exhaust manifold.  It will be where the exhaust gases exit your vehicle’s engine.  It likely will look rusty and either be a number of tubes, or one large tube.  Sometimes they are covered by a heat shield so look hard.  From there, follow the piping back under your vehicle all the way to the rear.  Look for any holes or places where the pipe has broken or come apart.  Also inspect each of the exhaust components as you go back.  There may be one or multiple catalytic converters, resonators or mufflers.  These will look like large metal tubes or boxes connected along the exhaust piping.  Check all of these for holes, dents or creases.  Don’t forget to check the top of each component with a mechanic’s mirror.

Exhaust leak repairNext you can do an audible inspection.  With your vehicle running start in the engine bay.  See if you can hear a distinct noise coming from near the exhaust manifold.  In this area an exhaust leak will sound more like a ticking or puffing.  Next listen for leaks at any union or joints in your exhaust system.  Once you get to your catalytic converter and go back from there, a leak will sound more like a buzz, hum or your car or truck will sound like a hotrod.  Usually, the louder the noise, the closer to the engine it is.  During this inspection, it may be helpful to have a friend rev in the engine intermittently so you can hear the changes in exhaust sound.  Remember, never touch the exhaust components during this inspection, they’ll be hot!

If you discover your exhaust leak to be coming from the exhaust manifold or one of the joints in your exhaust system you may be able to seal the leak simply by changing the gasket.  Each joint in your exhaust system will have a gasket that can be replaced, but remember the bolts may be hard to remove as they are usually rusty.

If you discover your leak to be from a break or hole in your exhaust system it will be difficult to fix it on your own.  You may be able to replace just the section of pipe or exhaust component by disconnecting the two closes joints and replacing the entire section of exhaust.  That option is often expensive and can be difficult to do because of rusted bolts and connections.  The best thing to do in this case is to take your vehicle to a muffler repair shop that can weld in a new section of pipe or component to make sure your exhaust system is leak tight.

Exhaust leaks can be very dangerous as they will let exhaust gases into the cabin of your vehicle.  Exhaust gases are not only bad for the environment, but they are bad for you!  Inhaling vehicle exhaust fumes can make you uncomfortable in the short term but may lead to serious health problems and even death!  If at any point you smell exhaust fumes in your vehicle, have it checked out by an exhaust shop immediately.

Pictures provided by: www.kwik-ft.com and www.ultimatesubaru.com

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24 responses to “How Can I Fix My Exhaust Leak?

  1. I would have to agree that fixing the problem is easier than it sounds. You need to identify the problem first, and that can be really tough to do. If all else fails you can take it in to get the exhaust repaired by a professional.

  2. I just want to thank you for such a thourough explanation! i hope this forum is not just for mechanics. if it is i do apologize. The only thing i am still wondering about are the SYMPTOMS. you mentioned exhaust in the cabin , are there any others. i am experiencing exhaust in the cabin, but also puttering in the engine. could this be the result of leaks in my exhaust system? please reply. Thank you!

    1. Minnie,

      Thanks for your question about your exhaust leak. Exhaust in the cabin of your car is a sure fire way to prove you have an exhaust leak. This can also cause your car to run poorly either from being imbalanced or because your system’s sensors aren’t reading properly. The best way to get an exhaust leak fixed is to take your car to a shop that specializes in welding and exhaust work.

      1. Yes, I followed this advice and thank you, I took it to a shop where they do exhausting welding and it was the converter part of the muffler, he said if he didnt weld it it would cost like 500.00 for labor and the converter, he asked me if he could weld it and he only charged me 50.00 dollars, the mechanic saved me 450.00 and there is no more exhausting leaking anymore. Thank you so much for this.

  3. Thanks the great in depth article. I learned a lot and think it helped with my problem but wanted to ask a question about clamp on vs welded exhaust kit. I bought a pre welded clamp on kit for my Toyota Tacoma and had a friend put it on for me. He did quickly but now it’s loose where the pipe meets the catalytic converter- and the cc is rusty and old. It must’ve slipped out or a bad clamp/fit because it was quiet for a week but now I’m going deaf driving to work and back. Any suggestions or just bring it to a pro?

    1. Shane,

      Thanks for your question about your Tacoma. Usually, clamp on exhaust kits work great as long as you have the correct size piping and clamp to go along with it. Try measuring both sides of the pipe and the clamp to make sure everything is the correct size. At the end of the day, if you only have that 1 connection to weld, it would probably be relatively inexpensive for a shop to weld that up and would create a more permanent connection.

      Thanks again for your question!
      -BD Auto Pro

  4. could the scanning code for Mass Air Flow sensor be caused by an exhaust leak? That code has come up over and over since July. Two mechanics have replaced the MAF sensor four times, twice with new parts and twice with used parts. The code is still coming up (exhaust leak is the last thing that has to be fixed, a flex pipe leak in front of the catalytic converter.

    1. Cynthia,

      It is possible that your exhaust leak could trigger a mass air flow sensor error depending on where the leak is in correlation with your oxygen sensors in your car. If the leak is before one or multiple O2 sensors it could confuse your car’s computer as it’s trying to calculate how much fuel is needed. You may also look for vacuum leaks in your engine as they could lead to MAF errors. Lastly, you could check for electrical problems in between your MAF sensor and your engine’s computer as a broken or grounded wire could also cause that code to pop up.

      Thanks again for your question!
      -BD Auto Pro

  5. Hey amazing report by the way,
    I have a 2007 Eclipse GT and just recently noticing a sound that like of Air escaping from other the car.
    I will follow your step for sure inspecting the exhaust system, but i was wondering if exhaust leaks will make the check engine light go on? Mine has not gone. More about the leak sound is that It sounds off every time i Rev the car and most likely its doing it while driving it. what do you think?

    1. Samuel,

      Thanks for your question! An exhaust leak will cause a check engine light on your car if it is anywhere before you bank 1 oxygen sensors. Usually these sensors are pretty close to the exhaust manifold so an upstream leak is unlikely.

      Thanks again for your question!
      -BD Auto Pro

  6. Hi so this may be stupid but want to do it for a laugh. I want to do a washer mod exhaust but I’m not keen on idea if it damages the car like engine gearbox ect can you give me some info on this topic because if I do it for a laugh it will be a exhaust leak so want to clarify details before killing myself or my car

    1. Sean,

      Thanks for your question. I’m assuming you mean using washers to add a space in between a section of exhaust piping on your car to make it louder. As long as you add the washers downstream of your catalytic converter it shouldn’t affect the function of your car or be dangerous. Part of the danger of this is that you’ll be allowing exhaust gases to escape underneath your car which can be dangerous as they can accumulate in the cabin of your vehicle and be dangerous to you.

      Thanks again for your question!
      -BD Auto Pro

    1. Mercedes,

      Thanks for your question. Usually, an exhaust leak will simply make your car louder and could allow you to smell exhaust fumes in the cabin of your car. If the leak is before your bank 1 oxygen sensor then it could make your car run very poorly and could make it lose power. Either way we would recommend you getting your exhaust leak quickly to make sure your vehicle runs properly and you stay safe driving it without inhaling exhaust fumes.

      Thanks again for your question!
      -BD Auto Pro

  7. Thanks for the explanation.. It helped ma a lot understanding my vehicle.. I’ve facing the same like problems.. These days I’ve been hearing the same kind of sound… At the service center they r telling to replace CTR.. But It’s expensive… One more thing is there anyway DAT I can weld the holes in the exhaust pipes..??¿

    1. K Vilas,

      Thanks for your question about your exhaust leak. replacing the cat is expensive. Depending how big the holes are in your exhaust you can often weld them. If the hole is less than 1/4″ in diameter you should be able to weld it shut and get your vehicle back to normal. You can also try just replacing the a small section of the exhaust pipe to seal the leak as well.

      Thanks again for your question!
      -BD Auto Pro

        1. Dawn,

          Thanks for your question about your exhaust leak. Depending on what kind of car you have, your vehicle probably thinks there is an exhaust leak because it is getting different readings from oxygen sensors on different sides of your motor. This could indicate one of those oxygen sensors is going bad or it could indicate an unbalanced condition in your motor. You could start by performing a basic tune up on your car including cleaning the fuel system and replacing the spark plugs. You may also check your oxygen sensors for proper operation.

          This could also indicate you have a clogged catalytic converter on one side of your car so you may consider having those inspected as well.

          Thanks again for your question!
          -BD Auto Pro

  8. Thanks for really a great and neatly written post. It helped my understanding of the system and think before taking it to repair shop. I am driving 1999 honda civic lx for more than two years. Recently I fixed the slightly loose bumper after another car hit from back slowly. I fixed it just by hitting and pushing the bumper connecting metal with hammer. At that time I remember, I might have touched the tailbox and end of tail pipe. Most probably after that I hear little more noise from the exhaust end. At the time of driving I feel that for speeding up it takes little more time compared to few weeks back. I tried to get the sound from the engine side but it’s not on that area, feel like all from exhaust side. Do you have any idea what could happen? Thanks in advance.
    -Reza

    1. Reza,

      Thanks for your question about your 1999 Honda Civic. It does sound like you could have damaged your exhaust system by bumping it while fixing your bumper. Based on the age of your car, if the exhaust system was original it was probably very rusted and thin so even a light bump could have caused a hole or break. Usually, broken exhaust pipes don’t cause a lack of power, but depending on where the problem is, it could. If you can grab your tailpipe (when your car is cold) and shake it easily you may consider taking your car to a muffler shop to see if they can repair the exhaust leak.

      Thanks again for your question!
      -BD Auto Pro

    1. Katie,

      Thanks for your question about your exhaust fix. Unfortunately, we can’t help you estimate the cost of exhaust work where you live as the prices vary significantly from country to country and shop to shop. Our recommendation would be to go to a few local shops in your area and ask for an estimate on how much the work would cost to get the best price.

      Thanks again for your question!
      -BD Auto Pro

  9. It’s early on Anzac Day in Australia so nothing’s open so I’ll take a shot here.
    Noticed a rattling from my exhaust near the tailpipe over a couple of days. Yesterday I gave it a gentle waggle and it became very lose. Checked under to see the connection into the silencer is rusted out. The big difficulty now is that I can’t get it to start! Could this be the cause? And is this the kind of thing a repair kit could handle? Or am I going to have to get a mobile mechanic into my apartment car park?
    All help and advice appreciated.
    Al

    1. Al,

      Thanks for your question about your exhaust system. Depending on the thickness of the metal, you may be able to simply have the connection from the pipe into the silencer welded and have your problem fixed easily. In the worst case you would need to get a new muffler attached to your exhaust system.

      In our experience, the exhaust problem you’re having should not cause your car not to start and the problem is most likely a coincidence. If your car wont even crank, try checking the battery and the starter. If your car is cranking but wont start, check for engine codes and check for the proper fuel pressure and the presence of spark.

      Thanks again for your question!
      -BD Auto Pro

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