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Hello all,

I had a heat shield (the one over my front catalytic) completely rot off from my 2008 Outback over the weekend. I live in Massachusetts where we oversalt the roads, so undercarriage corrosion is often a problem.

I read a bunch of posts here about heat shields, but most say to reattach it with a hose clamp. Mine is corroded through so that's not an option. And after reading some posts online, I'm also scared that I will die in a car fire without it.

My question: Is it worth replacing? I'm guessing other heat shields will go soon too and I found this heat shield kit online for $37: 2008 SUBARU OUTBACK Exhaust Heat Shield

Thanks for any help. And please respond before I roast in a car fire ... :)

-Linda

86,200 miles and counting ...
 

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Before you panic, you should understand the problem. Driving around without a heat shield won't hurt anything. Your car will not burst into flames.

HOWEVER... If you park the car in tall dry grass, the hot exhaust can potentially ignite the grass below the car without the heat shield to moderate contact. Not an issue on pavement/in garages etc.

It's a flimsy part, it's not a precision fit. You can use the Subaru part, you can reattach whatever is left with wire or hose clamps, or you can make one from scratch with soup cans. It's good to have.
 

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'14 Subi OBW, '18 Subi Forester
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While it is generally not a huge issue, heat shields also help to keep the catalytic converter heat in, and the system running at peak efficiency. From a design standpoint, it's one of those things that helps keep your converter healthy, especially when operated in a cold climate.

I'm not suggesting that you'll be dealing with the Check Engine Light on for a "Catalyst Below Efficiency" OBD code tomorrow, but in the long run, it's one of the contributors to it's early demise.
 

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2014 Subaru Legacy 3.6R, Venetian Red Pearl, EyeSight.
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I had been fixing mine by using clamps to stop the vibrating, but when I had it in for a service at the dealer last month I complained that I was hearing some rattling coming from the exhaust that I just had work on. They removed all the heat shields for no cost, and told me about it afterwords. I guess the dealer here in St. John's, Newfoundland, Canada doesn't think they're worth replacing or they would have recommended that I replace them. :)
 

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Unfortunately, dealers do a lot of unauthorized things instead of addressing problems properly. They are independent contractors. That doesn't necessarily make it a great choice.
 

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Discussion Starter #6
Thanks for the replies. So it's good to know my car won't burst into flames, but it seems like it may be a good idea to buy that $37 heat shield kit? My mechanic probably wouldn't mind installing it the next time I get an oil change.
 

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2001 Outback EJ25-5MT - 406,000km, 2016 Outback Limited Tech-FB25-CVT6 - 9,000km
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My heatshields are all original on my '01 Outback with 300,000km on the odometer, with 13 Canadian winters of experience. I live in an area where salt usage is high, and the humidity is also high.

I just completed my second total repair of the heat shields. I dropped the exhaust from the engine to the donut gasket. I removed all the heat shields, including the ones that are spot welded on, as well as the ones that are "fold attached" on the front pipes (I beleive your 2008 is quite a different layout). I used stainless steel scouring pads as an insulator between the heat shield and exhaust as wall as some stainless steel sheet under some of the clamping areas to allow the clamps that remain (most of rusted away) to clamp tight. All the bolts are now stainless steel, and a few stainless steel hose clamps are used where the original clamps have failed completely. I have had to do this job twice, one partial job five years ago, and just this past week-end a complete rebuild. After a few hours of work the car's exhaust is silent, and I should be good for a few years.

I also had to replace a flange ahead of the donut gasket, that was easy. A 2" split fix a flange was installed.

If at all possible you need to retain the heat shields. Sure the reduce the risk of grass fires, and thats not a big deal. The big deal is that they protect your exhaust system from thermal shock. The thermal shock of water spray from running through a puddle hitting the exhaust is mitigated by the heat shield. Failures from crrosion, cracking, and such will occur sooner if the heat shields are missing.

Also as mentioned by others, the catalytic will heat up faster, and until it starts "converting" you fuel economy is not optimal, as the engine computer may stay on tables rather than using its O2 sensors to the fullest.

Also the heat from the exhaust is one culprit in the Subaru saga of head gasket, and valve cover gasket failures. The heat shield will reduce the heat that impacts these gaskets.
 

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2006 WX8, 59E
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That's right, it's not the heat shields which rot out, but actually the clamps and bolts. Nothing too difficult to fix.
 

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2009 Outback 2.5i Special Edition
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I have an 09' Outback 2.5i, I bought it used and apparently someone has already taken most of the back heat shields off, and the front one has a nasty rattle and an attempted hose clamp fix.

I'm thinkin of just redoing the heat shields, seems the parts would be ~$300 for OEM from parts.subaru.com

I didn't see any spot welds in the diagram, are they all bolts in the 09? Is it just drop the exhaust and rebolt everything nice and tight?

Thanks in advance
 

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2002 Outback
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Rattling heat sheild

I have a 2002 Outback with rattling shields. The mechanic I spoke to suggested replacing the pipe and catalytic converter at the same time $2000 fix. I just had pipe replaced from the converter on back for $700. These repair can total more than the car is worth. I am torn as to what to do next. Any suggestions? I am thinking removing the shields and unloading the car. It only has 80K miles.
 

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I simply cannot abide useless people.
2006 2.5i and 2002 3.0 wagons.
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I have a 2002 Outback with rattling shields. The mechanic I spoke to suggested replacing the pipe and catalytic converter at the same time $2000 fix. I just had pipe replaced from the converter on back for $700. These repair can total more than the car is worth. I am torn as to what to do next. Any suggestions? I am thinking removing the shields and unloading the car. It only has 80K miles.
Get a new mechanic, you (likely) gots ripped off.

An exhaust shop should be able to reweld anything you need for well under $200. No reason to replace the cat unless you KNOW it is bad (glowing, smelling, or obviously broken apart internally).

Kaylee's exhaust is a combination of hose clamps and steel wool on minor rattles, and new pipe welded in on broken apart connections.

I had 2 broken pipe patches put in to replace rusted out connections, heatshield rewelded together, and some other misc minor working as the exhause from the cat to the muffler wasn't attached to anything except a hose clamp. Ran me about $120 or so I think.
 
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2005 Outback R LL Bean 3.0 H6 w/ 5 speed sport shift
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Something I've observed on my OB. The pipe upstream of the cats could use a sheild too because it is located directly below the power steering rack boots (on the H6 at least) and I'm certain that's not good for the boot. I have subsequently purchased some high temp silicone spray, specifically designed for exhaust, and heat shield fiberous tape which I wrapped the pipe and now it's much cooler in that area. Summit Racing had both products, Oreilly's had the tape but not the spray silicone.
 

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