Engine exhaust manifolds are the metal components that are responsible for collecting exhaust gases and transporting them to the exhaust for expulsion from the tailpipe. They are bolted to the engine cylinder head(s) and are sealed using a gasket known as the exhaust manifold gasket.
The exhaust manifold gasket is usually a multi-layered gasket that contains metal and other materials that are designed to provide the best seal possible. As the exhaust manifold gasket is the first in the exhaust system, it is a very important seal that should be inspected if any problems arise. When it fails or has any issues, it can cause all sorts of problems for the vehicle. Usually a bad or failing exhaust manifold gasket will produce a few symptoms that can alert the driver of a potential issue.
1. Excessively noisy engine
One of the first symptoms of a problem with an exhaust manifold gasket is an excessively noisy engine. A faulty exhaust manifold gasket will produce an exhaust leak that will sound like a hissing or tapping sound coming from the engine. The sound may be especially pronounced during a cold start or during acceleration.
2. Decrease in power, acceleration, and fuel efficiency
Engine performance issues are another common symptom of a problem with an exhaust manifold gasket. If the exhaust manifold gasket fails, the exhaust leak can result in engine performance issues such as a decrease in power, acceleration, and even fuel efficiency. The performance decrease may be minor at first, but will worsen over time if not addressed.
3. Burning smell coming from the engine bay
Another symptom of a potential problem with the exhaust manifold gasket is a burning smell from the engine bay. If the gasket fails and leaks near any plastic components, or engine wiring, the heat from the exhaust gases may cause the components to burn up. This may result in a burning smell coming from the engine bay as a result of the components being exposed to such high heat. The smell may sometimes be accompanied by faint smoke. Any sort of burning smells should be checked out as soon as possible to make sure that they are not a potential safety hazard.
Exhaust manifold gaskets are one of the most important gaskets of an engine, as they are the main gasket that seals and pressurizes the entire exhaust system. When the exhaust manifold gasket, or gaskets fail or have an issue, it can cause problems with the performance and drivability of the vehicle. If you suspect that you may be having an issue with your exhaust manifold gaskets, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if your vehicle needs an exhaust manifold gasket replacement.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Exhaust Manifold Gasket and was authored by Ed Ruelas.