A key component of your car's engine and exhaust system, the exhaust manifold serves two important functions. First, it collects the exhaust fumes from the engine into one location before sending it out through the tailpipe. Second, it builds up a balanced level of pressure to ensure that the engine runs at its peak performance.

When the exhaust manifold becomes cracked, however, it is unable to perform these functions, which adversely affects the way your car runs. Besides the smell of exhaust fumes coming from under the hood, there are a couple of other signs that you should look for when trying to determine if the exhaust manifold is cracked and needs to be replaced by an auto repair technician.

1. You Hear a Hissing Noise That Gets Louder as Your Car Goes Faster

One sign that is usually present when the exhaust manifold is cracked is a hissing noise that is made when the exhaust is forcibly expelled through the opening. As the car accelerates and the engine builds pressure, this hissing sound will become louder.

Along with the hissing noise, you may also hear the clickety-clack sound of the valves located underneath the exhaust manifold, which can be heard because of the cracked casing. If you hear these sounds, you will probably need to have the exhaust manifold replaced.

2. You Notice a Marked Reduction in Your Car's Performance While Accelerating

Another sign that your car's exhaust manifold is cracked is when you notice a marked reduction in your car's performance while accelerating. As the exhaust fumes are released through the crack, the engine will start to lose pressure.

Since air will also enter into the crack in the casing, a backflow is created that further reduces the engine pressure. As a result, you will find that you lose power whenever you try to step on the gas or attempt to climb a hill.

After noticing the hissing noise and reduction in performance from your car's engine, open the hood of your car to examine the outer casing of the exhaust manifold, which is the folded part typically located on the top of the engine. You should be able to see the crack in the manifold's outer case. If you know or suspect that your car's exhaust manifold has a crack in it, take your vehicle to a shop that offers auto repair services to have them inspect the part to see if a technician needs to replace it.