As you could guess from its name, a heat shield is a part that protects the car and other parts from excessive heat. In terms of cars, a heat shield is a metal covering that is used to cover the exhaust system and contain the heat generated inside. Mostly, it is made of high-strength aluminium with a layer of ceramic for extra insulation.
It is usually wrapped around the muffler and the rear part of the exhaust where the heat is concentrated most of the time. It is a very important part of your car, particularly in terms of safety and you should always keep it in good condition to avoid any hazards. Let’s understand why a shield is important for your comfort and safety, and why you should not drive your car without one.
Is a Heat Shield necessary on a Car?
It’s not like your car won’t move without a heat shield, but as safety is a serious concern, it is important that you don’t drive your car without an exhaust heat shield and consider it necessary. Here’s why;
1 – Discomfort Inside Cabin
Modern cars usually have high-performance engines and produce a lot of heat in the process, thanks to the fast-running turbos and other upgrades in the powertrain. All this heat passes through the catalytic converter, via the exhaust pipes into the muffler, where it gets concentrated before being emitted.
If there is no exhaust heat shield, all this heat can pass into the cabin and make it really hot and uncomfortable. The air conditioning won’t work so well and the rear seat passengers can find it difficult to even sit on the seat, as it gets too hot.
2 – Damage to Car Components
Modern cars are light in weight and great in performance, thanks in part to the plastic parts and high-strength aluminium. With so much heat around the exhaust and muffler, these plastic parts can get melted.
Not only does this damage the body panel or some parts, but it can also damage any surrounding wiring, sensors, or lights. This can be a potential fire hazard and burn down the whole car if not handled timely.
3 – Fire Hazard
This is the major function and purpose of installing an exhaust heat shield on a car. This shield keeps the heat from reaching other car parts and prevents it from dissipating. The idea is to prevent any kind of potential fire hazard, due to the tall grass, plastic, a piece of fabric, or any other inflammable material that can come into contact with such high temperatures.
A car might be idling at a point where there is some leaked fuel or oil streak on the road, and if there’s no exhaust heat shield, the high temperature is highly likely to ignite it and catch fire.
4 – Paint Damage
Exposure to high temperatures can damage the paint of the car near the exhaust. The paint either starts to peel off in different patches or gets faded on the posterior side altogether.
Can I drive without the exhaust heat shield?
Technically? Yes! You could drive your car without an exhaust shield, but it is highly not recommended. As discussed before, an exhaust heat shield is a simple metal covering over the exhaust that prevents heat concentration and damage to other car parts. Being an insulator, it also prevents any fire hazard.
So, driving around with a lightweight metal covering over your car’s exhaust shouldn’t be a problem and it would be advisable that you don’t remove the exhaust heat shield, for your own safety.
Exhaust Heat Shield Replacement
Over time and with rough usage, exhaust heat shields can get damaged or worn out, and requires replacement. It is mostly due to enduring high temperatures, and bearing the grunt of stone chips and other debris on the road. You’d come across different symptoms that would indicate that a replacement is due, let’s have a look at some of those signs;
1. You’d experience high temperature and a general discomfort inside your car if the heat shield is damaged or worn out. As it cannot insulate the cabin and all the heat gets transferred to the car’s interior.
2. Rattling noise from the back side of the car, particularly from under the rear seats. It is due to the shield getting loose over time and hitting the other metal surfaces nearby, creating a crackling or rattling sound.
3. Burning smell after a long drive, specifically from the rear side of the car is an indicator of worn out exhaust heat shield. It could either be a burning plastic panel or ceramic layering of the shield itself.
4. Paint damage – this is a late sign and appears well after the stage of rattling noise and burning smell. If you ignore these signs and keep driving without replacing the shield, all that excessive heat is likely to damage the paint on the rear side of the car.
A brand new exhaust heat shield costs around $100-150 and it is ideal that you always get a new one, instead of an older part, for the sake of some bucks. Another option is to get an exhaust heat wrap, which is basically a layer of an insulating material, such as Teflon. It is cheaper to get and doesn’t even require a metal frame to hold it, saving you some money and weight.
Final Thoughts
A car produces a lot of heat due to the combustion process going on, especially the modern cars due to turbos and performance upgrades. All this heat is emitted via the exhaust system, which itself gets very hot during the journeys.
To protect the car parts, paint, interior, and nearby objects from this heat, automakers install an exhaust heat shield that acts as an insulator. It is a major protector against any possible fire hazard, and is an essential part of the car. It is advisable that you keep your car’s heat shield in a perfect condition, to avoid any mishap and don’t try to remove it for no reason whatsoever.
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