Finding an Exhaust Leak
Repairing small openings in an exhaust system can be fixed in a variety of ways. If you are really unlucky, it will not be gentle spitting sound, but a deafening roar. Your neighbors will believe that the street has been converted to a drag strip with you as the only entrant. Either way, it means that you have some exhaust pipe repair work to complete.
You never want to let this problem go unfixed. Carbon monoxide poisoning is no fun and can be fatal. Often, its victims do not even realize that they are in danger until it is too late. From personal experience, the first evidence you have of a problem is when you park your car. As you exit, you feel fine. The next instant you have passed out and fallen onto the pavement. It is no fun. Neither is the headache and upset stomach that come later.
The first step toward making a repair is to locate the leak along your exhaust pipe. With the engine running, put the car in park or neutral with the parking brake set and get down beside the car and listen for the leak. Usually, this works just fine, and you can frequently see the exhaust spewing out of the hole.
If you can hear it, but cannot quite pinpoint the leak, you will need to get under the car. Following proper procedures, jack the car up and put some type of safety stand under the axle nearest to the jack. This will keep the car from falling on you while you are under it. A failure to do this has resulted in new graves in the cemetery.
Once you are under the vehicle, it is usually quite easy to find the hole. You can actually feel the exhaust blowing out of the hole. Be careful not to touch the pipe. It is probably hot enough to inflict a nasty burn on human flesh.
Take a little time to look around under the car. Is your exhaust pipe held together with clamps or is it welded? Does it look like you can remove the section of pipe that has failed? After you have found the hole and made note of how your exhaust system is constructed, exit from under the car and turn off the ignition. It will need to cool for about an hour unless you like to work with gloves on your hands.
If your exhaust system is welded together, you may not be able to fix it yourself unless you have a welder and cutting torch. With a welder, obviously, you might be able to weld up a small hole and be finished. If not, you will have to cut the bad section of pipe loose with a torch or hacksaw. Under a car on your back, neither of these two options is much fun.
For a welded system that you do not have the equipment to fix the hole with a weld, I would recommend that you take it to a shop for repairs. This type of repair can take hours just to get the old pipe off and hours more to install a new one if the new one is designed to be installed with a clamp or clamps.
Assuming you can get the old pipe off by removing clamps or cutting it, you will need to loosen up the hangers in front and behind it to make it easier to slide in and out. Sometimes, it is even necessary to remove the hangers. You may need some WD-40 or one of its cousins to help get the bolts loose.
They make a tool for crimping and spreading the ends of exhaust pipes. Try to borrow one of these from someone rather than buying it because they are a little pricey. You may not need it if all of the pipes are cooperative. Slide the pipes together and clamp them as tightly as possible. If you do not clamp them tightly, they will eventually shake loose.
Reinstall any hangers that you removed and tighten them up on the pipe to hold it in place. Start the car and check for leaks. With no leaks, let the car off of the jack and put away the tools. If all has gone well, you should be finished except for the shower that you definitely will need.
