Exhaust manifold damaged by corrosion

[donpalino]

For the past year I was getting some noise from the exhaust near the engine. I was thinking the donut gasket was in need of replacement. The dealer could not find any issue. Then the noise got worsening recent weeks until I found the problem.



The exhaust manifold has a heat shield on top. The metal mounts welded in the manifold to support the lower part of the shield were broken, destroyed by corrosion. The rest of the manifold was in great condition so I guess is an issue with the quality of the metal used for the mount.



I stopped by a junk yard and checked a used exhaust manifold from a 50k. Also corroded, so I a not alone here. My Yaris was almost 5 years, 85K miles when I first heard the noise.



So I had to replace the exhaust manifold and the heat shield. I could blame the salt in the cold areas but 5 years is sort of a short time.



My question is, does anybody faced a similar problem?

[tmontague]

My '02 Echo has 350,000km on it and the heat shield rattles here and there. It's currently being held on by one bolt. The bottom two that you are talking about are completely corroded and the top bolt is so rusted it just snapped off.

I was going to replace my exhaust mani gasket but after looking at how rusted the bolts were I didn't even want to attempt it.

I spray my Yaris' exhaust mani bolts and heat shield bolts w/ anti rust coating every month or so. I will also be replacing the exhaust mani gasket on it this summer 140,000km simply so that I was put anti seize on the exhaust manifold bolts and make sure that they stay un seized in case it needs to actually be replace down the road.

Was a complete replacement of the exhaust manifold the only option to get a new heat shield? What was your price?

[Mikastef]

Guys, by any chance, did you get this sound regarding your exhaust?
LINK: https://www.dropbox.com/sh/n04pib5mastixcq/AABV6ppJcICPRuW3EV86o0Zba?dl=0

see my post
http://www.yarisworld.com/forums/showthread.php?t=54069&page=2

[donpalino]

Yes I had to replace both because the support washers in the cover/heat-shield were also damaged. Paid $130 for the manifold and $70 for the shield.



I listened to the mp3s but I can not say for sure the noise is the same. In my case some noise was present during acceleration, I am guessing now, when one of the screws lost support and later a loud tapping during idling when the second support failed.



The job requires to make space removing many parts between the windshield and engine. Check Service Manual for details. I also replaced the manifold gasket and donut gasket, given the opportunity.

[sheekeebut]

Guys, by any chance, did you get this sound regarding your exhaust?
LINK: https://www.dropbox.com/sh/n04pib5mastixcq/AABV6ppJcICPRuW3EV86o0Zba?dl=0

see my post
http://www.yarisworld.com/forums/showthread.php?t=54069&page=2

I get the exact same taps and rattles at idle, on those little intermittent dips in rpm, like when I switch the fan/ac on/off. The sound disappears altogether above 800 rpm

[shepd]

Heat shields fall off of many, many cars all the time with typically zero exciting results. However, they are typically there to deal with edge cases (parking over tall dry grass, towing heavy loads long distances during the summer, crazy people doing parking lot donuts, etc, etc).

I'm not saying to remove it, but if it's like any other heat shield I've seen, if it fell off, you'd never even know unless you happen to be an edge case (in which case, well, the results could range from a bad smell, to something melting, to, rarely, fire).

The exhaust manifold heat shield was missing from two of my previous vehicles (Corolla and a Crown Vic--both sides for that car). Nothing ever came of it, even for the years I drove them.

Of course, the right thing to do is replace them. I should probably re-paint the scratches on my car, too...