What's the Purpose of a Plastic Engine Cover?

Most automotive engines aren't completely exposed. After popping the hood and accessing your vehicle's engine bay, you'll probably discover a large plastic cover over the engine. It's a common part of most automotive engines. What's the purpose of this plastic cover exactly?

Reduces Noise

The plastic cover will reduce noise. Internal combustion engines (ICEs) produce a lot of noise. When driving at a speed of about 50 to 60 mph, your vehicle's engine will produce about 60 decibels of noise. The plastic cover, however, will reduce some of this noise. It won't make your vehicle's engine run silent, but it will promote a quieter ride, nonetheless.

Contains Wires

On some vehicles, the plastic cover is used to contain wires. Spark plug wires, for instance, may run underneath or through the plastic wire. The plastic cover will contain the spark plug wires by routing them from the battery to the spark plugs.

Keeps the Hood Clean

You might be surprised to learn that the plastic cover will keep your vehicle's hood clean. Engines can experience fluid leaks. Most automotive engines contain passages for oil and coolant. Oil is used to lubricate the internal parts inside of engines, whereas coolant is used to reduce heat and protect engines from overheating. If either of these fluids leak out of an engine, they may splash on the hood. 

The plastic cover will prevent oil, coolant or other fluids from splashing on your vehicle's hood. Even if your vehicle's engine experiences a leak, the plastic cover will shield the hood from splashes. It won't prevent leaks from occurring. Nonetheless, the plastic cover will prevent fluids from splashing on the hood. You may notice fluid leaking underneath your vehicle, but the hood should remain clean thanks to the plastic cover over the engine.

Looks Nice

Another reason automotive engines feature a plastic cover is for aesthetics. It creates a cleaner appearance. Without the plastic cover, your vehicle's engine will be completely exposed. Automotive engines are often dirty. A plastic cover will enhance the aesthetics of your vehicle's engine by concealing it. You won't be able to see the engine. Instead, you'll see the plastic cover, which is probably cleaner than the actual engine.

In Conclusion

While some motorists remove the plastic cover, it serves several purposes. Plastic engine covers reduce noise, contain wires, promote a cleaner hood, and they look like.