Catalytic Converter Heat Shield Rattle, How To Fix

Last updated on February 14th, 2022 at 10:00 am

If you are looking for how to fix catalytic converter rattle, this is the post for you. The catalytic converter heat shield rattle is one thing that commonly happens which is caused whenever the heat shield becomes loose. Indeed, catalytic converters can get very hot, and this type of temperature is too much to automatically ignite the oil, the transmission fluid, and grease.

When you hear any metallic rattle sound coming from your car or truck as you’re idling, then you probably have a loose or broken heat shield. But how do you get it fixed? Before I answer this question, let’s learn how heat shield sounds. Read this post too

Table Of Content:

How Does A Heat Shield Rattle Sound?

You will hear some sounds whenever you have a loose or broken heat shield, below are some of the sounds.

Rattling Sound

Whenever you hear rattling sounds that seem to be coming from under your vehicle, then it could be coming from your catalytic converter. You will even notice that once the catalytic converter reaches temperature, you may not hear it again.

Ticking or Knocking Noise

Whenever you hear a ticking or knocking noise coming from the catalytic converter, this might be caused by one of several problems. Some cars do indeed make this kind of sound while idling. But it could be possible that it’s because of a leak in the exhaust. No matter what, you’ll hear more catalytic converter noise while you accelerate.

Catalytic Converter Heat Shield Rattle: How To Fix A Heat Shield Rattle

Here are the steps you need to when fixing a Catalytic Converter Heat Shield Rattle.

Step 1: Converter’s heat shield bolts should be sprayed with penetrating oil around one hour before starting work.
Step 2: Take off the heat shield bolts before taking the heat shield off. The heat shield should be washed with soap and water. Take a look inside, it might look dull and discolored. Make sure to polish inside of the heat shield using 200-grit, 400-grit, and then 800-grit sandpaper, this will make it to be bright and shiny.
Step 3: Now cut off two-inch of the header wrap. In case you don’t know, the header wrap is like fabric meant to wrap around primary tubes to ensure heat remains inside the header.
Step 4: Put half-dozen washers around the heat shield bolts, by keeping them flat on the header wrap. With fast-drying spray paint, hit them quickly. Whenever the washer is removed, you’ll see a better outline of them on the header wrap. Just cut off the wrap washers using scissors, and trim the middle off with a penknife.
Step 5: The penetrating oil should be cleaned from the bolt threads and put a dab of an anti-seize compound that’s of the same size as a pencil eraser. Put one or two of the wrap washers around the heat shield and the converter. Once done, reinstall the heat shield with the lock washers.

The heat shield bolts should be tightened to factory spec. But you should try to jiggle the heat shield. However, space should’ve to be taken up by the wrap washers which is caused by bolt stretching.

How Much To Fix Heat Shield Rattle

To know how much to fix the heat shield rattle, your vehicle needs to be taken to the repair shop for assessment. On Average, the cost of fixing a heat shield rattle is around $150 to $500. Usually, the parts should cost $150 or less and it shouldn’t take more than one hour of labor, which not be more than $300.

Do I Need A Heat Shield On My Catalytic Converter?

When there’s a gap in the exhaust system, your car can run poorly except it is fixed. You need a heat shield on your catalytic converter, and there’s a reason manufacturer put it there.

Note that it is illegal to drive your car without a heat shield on the catalytic converter. A catalytic converter without a heat shield can heat the interior of the car, which may cause a fire if you park on dry grass.

How To Fix Exhaust Heat Shield Rattle

You don’t need to remove the heat shield when using this simple method to fix it. This is because when you remove the heat shield, it can cause problems with sensors, wiring, and close rubber components.

To fix a Heat Shield Rattle, follow these steps:

1. The Screw Hose Clamp should be loosed

2. The Exhaust Component and Heat Shield should be wrapped with the Hose Clamp

While the engine is cold, the exhaust component and heat shield should be wrapped using a hose clamp about a half inches.

3. Now the Hose Clamp should be tightened to Clamp the Heat Shield in Place

Using a flat blade screwdriver, the hose clamp should be tightened until the broken piece of the heat shield is clamped very well to the exhaust manifold.

The heat shield should be tightened using an additional 2-3 hose clamps, which will provide more security.

4. Make sure the Heat Shield is tightened

You can tap the heat shield to see how tight it is.

Cat Converter Heat Shield Rattle

In case you don’t know, the catalytic converter happens to be a device that is part of the exhaust system in your vehicle.

This device makes use of catalysts like platinum in creating a chemical reaction that reduces harmful pollutions. Note that the catalytic converter is designed with three main components.

Heat Shield for Catalytic Converter Rattle

The heat shields rattle is a welded sheet metal component inside a vehicle meant for a catalytic converter that can rust after years of usage as it is exposed to daily wear and tear.

One of the important of Heatshield for catalytic converter rattle is that it doesn’t just rip remove a rattling heat shield, it’s a protector.

With it, your vehicle can still be driven, but it’s a required safety feature designed for cars for a purpose.

Conclusion

The catalytic converter happens to be one of the components on your vehicle that you should probably replace when it gets worse even if it can be expensive. Whenever you find out that it’s rattling or knocking, then it’s time to get it replaced.

However, even if you can’t get a new one, you can try as much as can to clean it out so that its performance can be restored.

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Jeffery Ekweghi

Hi dear, my name is Jeffery Ekweghi, and I am a certified mechanic and autobody parts technician. I created this site to share my expertise and experience with car lovers looking to resolve their car-related issues. I am certified in private cars and heavy-duty commercial vehicles. I have worked as a mechanic since 2015 and have experience in vehicle brands like Subaru, Jeep, Toyota, TATA, BMW, Mazda, Honda, Nissan, Kia, TVs, and Others; however, I primarily specialize in Toyota vehicles.