Your exhaust manifold requires a seal between the cylinder head and the exhaust manifold. This seal is called the exhaust manifold gasket, and is an incredibly hard-working part. The exhaust manifold is where all the engine cylinders’ burned gasses travel in order to make it through the exhaust system and out the tail pipe. The gaskets create that perfect seal so that nothing leaks and escapes.
When you think about the extreme heat that is passing through the exhaust manifold, it’s no wonder that the gaskets can become worn down and damaged. Often it is referred to as a "blown gasket" once it breaks. Other reasons it can fail is if a bolt breaks off, which then affects the seal. These leaking gases cause the engine to take a hit where performance goes as well it can be quite hazardous since these gases are escaping from the vehicle. While there is no set mileage that this gasket will blow, it is a given fact that eventually it will happen. It's just normal wear and tear on the car.
Here are some signs you can watch for that may signal your exhaust manifold gasket has blown, and reached the end of its lifespan:
Because the gases will be escaping and leaking, there's a good chance your vehicle will be unable to pass an emissions/smog test. Once you get the part replaced, provided that was the only issue, you should be able to pass the test.
A leaking or blown gasket will result in decreased engine performance, which means your Check Engine Light will probably come on. A certified mechanic can read your computer codes to determine exactly why this light has come on.
You may start to smell an odd smell coming from the exhaust area of your vehicle, since there is a leak. As well you might start to hear a tapping or ticking sound while driving, more-so when your vehicle is cold.
The exhaust manifold gasket is what forms that seal between the cylinder head and the exhaust manifold. Once this breaks or starts to leak, you’ll have a variety of issues start to pop up. As well your engine performance will deteriorate. If you’re experiencing any of the above mentioned symptoms and suspect your exhaust manifold gasket is in need of replacement, get a diagnostic or book an exhaust manifold gasket replacement service with a professional mechanic.
This article originally appeared on YourMechanic.com as How Long Does an Exhaust Manifold Gasket Last? and was authored by Valerie Johnston.