Author Topic: Replacing heat shield for catalytic converter? (Read 18667 times)

CommonCents

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Replacing heat shield for catalytic converter?
« on: December 19, 2014, 01:32:58 PM »
Small rattle turned into larger rattle turned into something dragging on the ground. Random guy said it was the heat shield for the catalytic converter. Yes the sound is bad enough two strangers have pointed it out to us. (Note: In September, something fell of the car while driving that looked like a shield. For various reason, we never did anything about it. Google says heat shields are in two parts, so may this may have been it.)

DH generally adopts an ostrich-like approach to car repairs - if the car is still moving, he won't do anything (take it in or fix it). Is this hard to do by ourselves (outside, in a boston-winter)? How long would it take? (We're in a bit of a time crunch with plans to drive north to visit family on Christmas, and only a few hours free this weekend.) I assume we'd need to buy a jack for it plus any tools, since I've never done anything for a car before. Is it an expensive/lengthy repair if we are unmustachian and take it into a shop?

Honda Civic 2002

BlueMR2

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Re: Replacing heat shield for catalytic converter?
« Reply #1 on: December 19, 2014, 01:40:23 PM »
You've got 2 choices that I see.

1) Replace the cat - pricy for parts and painful for labor for a car of that age.
2) Get some good high-temp heatshield material and construct a replacement. This is the route I went when the heatshield fell off my cat a year or so ago. Proper engineering is key, you need to duplicate the way the stock piece functioned (usually has an airgap with standoffs and is designed to NOT trap leaves/grass/other things that burn well).

CommonCents

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Re: Replacing heat shield for catalytic converter?
« Reply #2 on: December 19, 2014, 01:53:46 PM »
You've got 2 choices that I see.

1) Replace the cat - pricy for parts and painful for labor for a car of that age.
2) Get some good high-temp heatshield material and construct a replacement. This is the route I went when the heatshield fell off my cat a year or so ago. Proper engineering is key, you need to duplicate the way the stock piece functioned (usually has an airgap with standoffs and is designed to NOT trap leaves/grass/other things that burn well).

So the heat shield falling off requires replacing the entire cat? (Sorry, I'm pretty ignorant on cars. In my defense, excluding my marriage of 2 years to my car-owning husband, I have personally only owned a car for a total of four months. I'm 35.)

If we don't park on grass, is there any issue to simply not replacing it?

craiglepaige

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Re: Replacing heat shield for catalytic converter?
« Reply #3 on: December 19, 2014, 02:05:13 PM »
What brand and model car do you have? What engine does it have?

Most heat shields around the converter are two pieces, bolted to one another, through a "key hole" on the actual cat. If the "key hole" corroded and broke off, you wont be able to quickly replace the shields. If its still there, you will problably have to removed the rusted out bolt/nut. It's hard to figure out what you have without knowing the brand/model/engine of car.

As far as replacing the shields, I'm 99% sure you will likely have to go with the dealership as aftermarket companies don't really sell these. One other thing you can use is a heat wrap, secured with metal clamps, like this. (you can get them at the local auto parts store or online).
-The conqueror will always become a slave to his conquest.

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https://youtu.be/GO1Fsp4cUTQ

craiglepaige

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Re: Replacing heat shield for catalytic converter?
« Reply #4 on: December 19, 2014, 02:08:34 PM »
Ooops just noticed your last part about the car...

Here http://hondapartsunlimited.com/auto-parts/2002/honda/civic-coupe/ex-trim/5-speed-manual-engine/electrical-exhaust-heater-fuel-cat/exhaust-pipe-muffler-scat

Part 6 and 7. Double check your vehicle model and transmission type. But that's a good site to order from.
You could buy both pieces and large metal clamps to secure it.
-The conqueror will always become a slave to his conquest.

- Eres Un Esclavo Financiero
https://youtu.be/GO1Fsp4cUTQ

CommonCents

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Re: Replacing heat shield for catalytic converter?
« Reply #5 on: December 19, 2014, 02:15:32 PM »
Thanks! Wow those parts are cheap compared to getting from the dealer. It's manual, two-door EX

craiglepaige

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Re: Replacing heat shield for catalytic converter?
« Reply #6 on: December 19, 2014, 02:21:39 PM »
Thanks! Wow those parts are cheap compared to getting from the dealer. It's manual, two-door EX

Hey look at that, I managed to guess the right car. I guess I should go get some lottery tickets ;)
Yeah I like that site for Honda parts and their shipping is quite fast.
Good luck!
-The conqueror will always become a slave to his conquest.

- Eres Un Esclavo Financiero
https://youtu.be/GO1Fsp4cUTQ

cartechguy

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Re: Replacing heat shield for catalytic converter?
« Reply #7 on: December 20, 2014, 07:06:00 AM »
Take off the heat shield and NEVER PARK on top of a leaf pile!! Removal is the easiest way!! It can get expensive and time consuming when replacing them and sometimes the replacement doesn't fit correctly!!

Retired ASE certified mechanic working at the beach in sunny FL!

Holyoak

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Re: Replacing heat shield for catalytic converter?
« Reply #8 on: December 21, 2014, 09:18:04 AM »
Quote
Take off the heat shield and NEVER PARK on top of a leaf pile!! Removal is the easiest way!! It can get expensive and time consuming when replacing them and sometimes the replacement doesn't fit correctly!!

Gotta say exactly what I would/have done personally, and while doing professional car service... Especially the spot welded kind, and good luck repairing the clamshell/2 piece type with clamps without rattles/vibrations in a 4 cyl car. I live in a state with mandatory emission inspections, and have never had an issue, or ever given anyone flack when I did these inspections for customers with missing shields.


CommonCents

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Re: Replacing heat shield for catalytic converter?
« Reply #9 on: December 22, 2014, 09:34:13 AM »
Quote
Take off the heat shield and NEVER PARK on top of a leaf pile!! Removal is the easiest way!! It can get expensive and time consuming when replacing them and sometimes the replacement doesn't fit correctly!!

Gotta say exactly what I would/have done personally, and while doing professional car service... Especially the spot welded kind, and good luck repairing the clamshell/2 piece type with clamps without rattles/vibrations in a 4 cyl car. I live in a state with mandatory emission inspections, and have never had an issue, or ever given anyone flack when I did these inspections for customers with missing shields.

So this is what we did, just removed the shield this weekend. We might try to replace it later, but if so we'll do it this spring/summer when it's warmer out. (Odds are we won't.) Thanks for the link to the Honda parts though, it will be handy later! (And kudos on guessing it correctly! Does this mean we have a mustachian approved-model?)

Good reminder on avoiding leaves :)

cartechguy

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Re: Replacing heat shield for catalytic converter?
« Reply #10 on: December 22, 2014, 06:46:28 PM »
I have taken off many heat shields in my 20+ years in the automotive repair industry and NEVER had a problem after the shield was removed!! Not worth the $$$ and time to replace it!!

Your car choice is great!!

Retired ASE certified mechanic working at the beach in sunny FL!

Greg

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Re: Replacing heat shield for catalytic converter?
« Reply #11 on: December 24, 2014, 10:29:57 AM »
Keep in mind the upper/top shield protects the car bottom from CAT heat. On long drives, or if the engine is not running right, the car floor could get very hot, and insulation or other interior damage could occur. Some cars' soundproofing (tar-like layers) are not designed to withstand a lot of heat.

guitar_stitch

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Re: Replacing heat shield for catalytic converter?
« Reply #12 on: December 26, 2014, 09:19:05 AM »
Keep in mind the upper/top shield protects the car bottom from CAT heat. On long drives, or if the engine is not running right, the car floor could get very hot, and insulation or other interior damage could occur. Some cars' soundproofing (tar-like layers) are not designed to withstand a lot of heat.

This. I have had it happen.

Grande

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Re: Replacing heat shield for catalytic converter?
« Reply #13 on: January 01, 2015, 06:31:41 PM »
Keep both the top and bottom parts and just use 1 (or 2 if you want to be really thorough) hose clamps. I 've done this on several cars and it works fine. Never an issue. $3 fix. If that.