Why does the engine exhaust manifold gasket leak?
2 Answers
If the engine exhaust manifold gasket is leaking, you can replace the interface gasket or seal the gap in the exhaust manifold. Replacing the interface gasket: You can first try replacing the interface gasket, as the leak may be caused by aging of the gasket. However, if replacing several gaskets doesn't solve the issue, a thorough inspection is needed. Sealing the gap in the exhaust manifold: You can use copper wire combined with the interface gasket. When the engine is hot, tighten the exhaust pipe interface gasket bolts at high temperature to compensate for the exhaust manifold's gaps and significantly improve the sealing performance. You can cut a piece of copper wire from an old cable, wrap it around the interface gasket, and then tighten the exhaust pipe bolts when the engine is hot.
Exhaust manifold gasket leakage is quite annoying, and I think it's mainly due to several reasons. The gasket material degrades over time, especially under repeated heating and cooling in high-temperature environments, making rubber or metal gaskets prone to becoming brittle and cracking—just like my old car after eight years of use. Then there's the installation issue; if the gasket wasn't aligned properly or the bolts weren't tightened enough initially, engine vibrations can easily loosen it. Additionally, prolonged driving or delayed maintenance allows dust and oil buildup to compromise the seal. I've experienced this before—when it leaks, there's a hissing sound, increased fuel consumption, and reduced power. It's actually not hard to fix: regularly check bolt tightness and replace the gasket, which usually solves the problem without costing much but makes driving much safer.
