How to Temporarily Fix a Hole in an Exhaust Pipe
Times are tough, and car parts are expensive, yet cars always seem to get damaged at the worst possible times. Exhaust systems are particularly vulnerable to bad roads and bad luck. At best, a damaged exhaust system is simply noisy. At worst, it may vent carbon monoxide into the vehicle cabin. Fortunately, most small holes in the exhaust pipe are fairly straightforward to patch. Here is a cheap, quick fix for many exhaust pipe holes that will tide you over for another month or two, until you can afford to get the part fixed properly.
You should have the tools you will need at hand before you start. Depending on the degree of damage to the exhaust pipe, you may need aluminum-based exhaust tape, heat-resistant cement (be sure it is approved for high temperatures), one or more pipe clamps, as well as a wire brush to remove any rust. A clean pop or soup can works well as a temporary patch: you will need tin snips to cut out the top and bottom and along the side, leaving you with a curved piece of aluminum you can wrap around the pipe. (Heavier cans will last longer, but a pop can is more likely to be available in a pinch.) Most exhaust fix kits, available at stores which sell automotive supplies, contain some variant of a patch, bonding agent, and clamp.
Always wait until your engine is cool before working on any part of your car's exhaust system. Exhaust gases are extremely hot, and can cause serious scalding burns. As well, carbon monoxide can quickly accumulate to lethal levels without any warning, so be sure to work in a well-ventilated area. On an annoyance level, heat can cause a hole to temporarily seal itself as the metal expands, making your job much more difficult.
Begin by brushing away all the rust you can see. With luck, this will expose the hole, if you don't already know where it is. To trace an unseen leak, visually examine the length of the exhaust pipe, especially where it bends over the rear axle where extreme temperatures combine with tensile stress to create cracks. In fact, any place where the pipe bends or is exposed is much more vulnerable to leaks, as are any gaskets. If you still can't spot the leak but your engine performance keeps insisting that there must be one, plug the exhaust pipe and have a friend look for where the exhaust is forced out. Be sure to do this in a well-ventilated area!
Once you have identified the hole, plug it with the cement, working your way inward from the edges to create a tight seal. Once the cement is in place, wrap the pipe tightly either with the exhaust tape or with the can. Expect to use a full roll of exhaust tape if you want the fix to hold for any length of time. If using a can, it should be clamped in place at both ends, or you could even use two pieces of appropriately-sized wire, twisted tight. This quick-fix is complete after the cement has had time to set.
Slightly larger holes can be jury-rigged closed in a pinch using only the can and clamps, although you should not expect to rely on this fix for very long.
If you find that the last part of the tail pipe has been seriously compromised, you will have to bite the bullet and get it properly replaced, although you may be able to find the parts cheap at an auto wrecker. Any substitutions are likely to block the exhaust gases, which will cause much more expensive damage to your engine.This stopgap solution should not take the place of proper repair. In the meantime, this quick fix should tide you over until you have the time and money for a proper repair.
