So you’ve noticed disturbing rattling sounds coming from underneath your car. You step on the brakes to check what must be wrong only to find out that the heat shield is loose. Like every regular person, your first thought is “let me get rid of this nuisance!”.
We strongly advise that you do not remove your car’s heat shield. It is dangerous and its absence can lead to fire hazards. You are only permitted to remove the car’s heat shield when it is damaged and you need to replace it. If the car’s heat shield is loose, quickly find a way to tighten it. You can weld it, use hose clamps to hold it, or screw loose bolts back into position.
A car’s heat shield refers to the thin metal covering the catalytic converter and muffler. This thin metal has two parts that serve two principal purposes. The upper part of the shield acts as a thermal barrier that prevents the inside of the car from becoming too hot. The lower part prevents tall grass and leaves that might be under the vehicle from getting ignited.
Reasons Why Removing the Heat Shield From Your Car Is a Bad Idea
To further prove to you that removing your car’s heat shield and not replacing them immediately is always a bad idea. Here are a few risks associated with removing the heat shield from your car.
To Prevent Damage to the Vehicles Components
Melting of vehicles components, particularly those made of plastic and rubber, under the hood of the car is traceable to a missing heat shield. This is common in places with extremely high temperatures. The heat from the exhausts can cause surrounding components to heat up too or worse, catch fire.
To Reduce Discomfort to Occupants of the Vehicle
Due to the increase in temperature inside the vehicle, the vehicle will become very uncomfortable to the occupants. The floorboard can get so hot that placing your legs on the floor will be nearly impossible. Also if the temperature in the car gets too hot it can cause dizziness due to shortage of oxygen.
To Prevent Fire Outbreak
It’s very possible for there to be a fire breakout when you remove your car’s heat shield. The first can be internal and the second is external. By external we mean, when you park your car over tall grasses and shrubs it’s very possible for the heat from the catalytic converter to ignite these grasses and cause fire. On the other hand, internal fires occur when flammable products are inside your trunk and the missing heat shield causes the car to heat up beyond normal.
To Increase Performance of Car’s Engine
The increased performance of the car’s engine also rests on whether the heat shield is functional. How is this possible you ask?
Well, apart from reducing the likelihood of fire hazards, a properly installed and functional heat shield fitted to the air intake outlets can reduce the intake temperature and increase the efficiency of combustion.
To Prevent Spending More in the Long Run
In a bid to save cost for a moment you might be digging a deeper hole for yourself when you simply remove the heat shield from the car. Fixing a faulty heat shield will cost you only a few hundred dollars about 150-300 dollars, while changing the car’s engine as a result of negligence can cost as much as $5000.
Ways to Fix a Faulty Heat Shield
We’ve identified the rattling sound a loosened heat shield makes to be the principal reason why several car owners choose to remove the heat shield completely. Here are solutions to this rattling sound
Required Tools and Materials
- Fastening tape
Replace the Heat Shield
Replacing a rattling heat shield is one sure way to ensure that the rattling sound ends.
For DIYers who have done this before; this should be a breeze, it also wouldn’t cost a lot. First, you need to opt for a compatible heat shield, remove the damaged one, and install the new one.
You would need little welding skills if the replacement heat shield needs to be welded. It might even be a screw on type or a combination of both.
We recommend the AC PERFORMANCE heat shield for folks who would like to don’t mind getting their hands dirty in a bid to fix their damaged heat shield.
However, if you are not totally sure you can replace the damaged heat shield, take your car to a trustworthy car shop and have them fix a new heat shield. This would usually cost about $300 in total.
Tighten the Heat Shield
Another effective way to fix a rattling heat shield is by tightening the heat. Tightening can be done by either welding the heat shield, using bolts, getting a hose clamp, or finding a tie.
Welding the Heat Shield Back in Place
If you have some welding experience and have access to a welder, you can easily tighten the loosened heat shield by tacking the heat shield back in place.
When using the welding method of fixing a rattling heat shield, ensure that the weld temperature is not greater than the melting temperature of the heat shield and exhaust pipe.
Using Hose Clamps
You can quickly tighten the loose and rattling heat shield with hose clamps. All you need to do is wrap the opened hose clamp around the loose heat shield. Once completely covered, tighten the clamp.
If the loose heat shield proves too broad for one hose clamp, you can get a second and even a third hose clamp. These clamps are cheap; all you have to do is wrap the first hose clamp into the second and use it to wrap the catalytic converter.
Here is a video illustration of how to fix a loose heat shield using a hose clamp
Key Video Takeaways
- Wait until the car is cold before proceeding to tighten the heat shield
- Add one or two more clamps if the loosened part is too wide
Heat shields that use bolts are easy to tighten if the bolts come loose. Ensure that you get a replacement bolt of the same size and fix them in the position where the missing bolt should be. If you do not find a replacement bolt of the same size, fender washers can come to the rescue.
Signs That It’s Time to Change Your Car’s Heat Shield
Knowing when to change your car’s heat shield can be a game-changer. It’ll save you from spending more on damages that faulty heat shields can cause. Here are some signs to look out for.
Rattling or Scraping Noises
The much-talked-about rattling sound underneath the car is the first sign that your car’s heat shield might be loose or broken. Rattling and scraping noises from heat shields are annoying and lead to further damage.
If the heat shield is loosened, screw it back in place with a bolt. If it is broken, we recommend replacing it with a new one.
Abnormally High Underhood Temperature
An abnormally high temperature from the engine bay of your car is one sign you shouldn’t overlook. It often signifies that your car’s shield is either not correctly fitted or is missing altogether.
Failure of the heat shield will cause the vehicle to feel hotter than it should, especially the front ends.
If you, however, have your heat shield installed correctly and the engine bay still gets abnormally hot, it might be time to get your automotive heat shield insulation checked.
The Burnt Smell From the Engine
Another tell-tale sign of a damaged heat shield will be a burnt smell coming from the car’s engine compartment. The excessive heat in the engine’s bay can cause some parts to melt when the heat shield is missing or faulty. Plastic and rubber parts are the most susceptible to melting.
However, do note that when you install a new heat shield, it is normal for you to notice an awful smell. This burning smell is due to the binders and starchers in the fiberglass thread. They need to burn off and cure. Do not worry; this smoke is nontoxic, even though it might smell awful.
Frequently Asked Questions
What Materials Are Best for a Heat Shield?
The best heat shield material is Aluminum. This is majorly due to Aluminum’s ability to manage and control radiant heat. Its high thermal conductivity and low emissivity rate attribute make it the perfect heat shield material. Another high-quality heat shield material is copper. However, avoid bronze and steel materials when choosing a heat shield.
How Long Does a Heat Shield Last?
The heat shield that comes with your car is supposed to last throughout the vehicle’s lifetime; however, due to rust that is caused by the moisture in the engine, the heat shield is more prone to failure.
What Is the Maximum Temperature a Heat Shield Can Withstand?
You’d be surprised to find out that heat shields made from aluminum material can withstand temperatures as high as 600°C, with some going as 1000°C, provided the necessary air gaps are available.
To prevent damage to vital components in your car and keep your vehicle in top performance, we must reiterate that you should not remove the heat shield from your car. If it gets loosened or worn out, replace it.