Inspecting Your Exhaust System
*MEDIUM*
Inspect your exhaust system every month. For convenience, combine the exhaust system inspection with the catalytic converter inspection. Examine your exhaust system as follows:
- Park the vehicle on level ground with the engine OFF, the parking brake engaged, and the transmission in PARK (for automatic) or REVERSE (for manual). Elevate the vehicle's rear end on safety stands and block the front wheels if additional ground clearance is needed to crawl under the car.
- Wait for the exhaust system to cool before inspecting it in order to avoid being burned. Crawl under the rear of the car; wear safety goggles and gloves.
- Examine the underside of your car from the tail pipe to the engine. Look for holes, cracks and dents in the exhaust pipes and muffler(s). Tap the pipes and muffler(s) with a screwdriver handle. Solid metal will ring; corroded metal will sound flat ("thud"). Look at the underside of the car body for black exhaust soot or grayish white deposits. They will indicate the location of a topside exhaust leak. Any leaks must be immediately remedied. To further identify leaks in visually inaccessible areas, perform the sound test.
- Grab the exhaust pipe at various locations and try to shake it. It should barely move. If it moves a lot, there is a defect in the system. Look for missing or worn exhaust pipe hangers, which are composed of brackets and clamps. The rubber insulator in a hanger absorbs vibration and may deteriorate as well. Loose, corroded, or missing hangers and supports will accelerate exhaust system wear and will contribute to broken exhaust pipes.
- If you have dual exhaust, repeat the above two steps for the opposite side of your car's underbody.
- Repair or replace missing or worn exhaust pipe hangers. Do not use substitutes such as a reshaped wire coat hanger. Have cracked or corroded mufflers replaced immediately.
- You can patch small holes with high temperature tape found in exhaust pipe repair kits. Follow the directions on the kit. If the patch does not hold, have the exhaust pipe replaced.
- If large holes, cracks or dents are found in the system, have a professional automotive technician replace the defective component.
- Check the heat control valve (heat riser) in the exhaust manifold periodically to make sure it is working (if engine is so equipped). The valve should move under finger pressure. Lubricate it with solvent, not oil, as necessary.
- Remove the vehicle from the safety stands if necessary. Remove the front wheel blocks if utilized.
