exhaust manifold heat shield (noise)

[rayfloyd170]

Last 6 months ago, I heard some minimal rattling sound due to the exhaust manifold heat shield specially during low rev and during acceleration.

I removed 3 bolts holding the heatshield and could not find any suspect other than some kind of circular metal washer "sponge" but it is fixed and could not be removed. i was thinking this could come a little loose and generating the noise.

i have managed to solve the issue by putting a small amount of white grease
on the metal "sponge" washer and this temporarily solves the problem for some time. Now, intermittently this noise is coming back and again i put some grease and this puts the noise away.

Other than completely removing the exhaust heatshield, what can you suggest to permanently eliminate this minimal rattling noise?

What kind of grease is best suited for this?

Thanks in adv.

[bronsin]

Sounds to me like you have a pretty good handle On the problem.

[kevinj93]

I put a slight bend in the heat shield near the bolt holes / washers that you mentioned. Just enough so that the washers hold the heat shield tight and stop it rattling.

[rayfloyd170]

I put a slight bend in the heat shield near the bolt holes / washers that you mentioned. Just enough so that the washers hold the heat shield tight and stop it rattling.

Thanks a lot for the tip

Will do it this weekend on my rest day.

[rayfloyd170]

I finally took off the exhaust manifold heatshield today and was really surprised, all this time 1 out of 6 metal "sponge" washer was missing. This definitely caused the rattling noise due to imbalance as the metal washer functions as a cushion which sandwiches the heat shield.

I don't know if there is a particular part number for this or any store selling it, kindly let me know

Here goes the photo below.

[bronsin]

Outstanding post! So many times you hear about rattles, but it’s hard to find what does it.

Now we did

[kevinj93]

Unfortunately the service manual doesn't list these as a separate item. It only shows the heat shield. The torque figure for the bolts at reinstallation is listed as 71 inch-lbs.

[rayfloyd170]

Yes @kevinj93, you are right toyota does not sell it individually and they want you to spend for the whole assembly of the heatshield. Thankfully i managed to slice one thicker metallic anti-vibration washer into 2 equal parts. I managed to put it back since it is a bit flexible, perfectly sandwiches the heatshield without rattling.

Very happy now, no more noise during slow rev and acceleration. i will try to search in the scrap yard sometime whenever i am free.

I find this part online but only selling in bulk from India --> https://www.indiamart.com/proddetail/anti-vibration-washers-12873693162.html

knitmesh --> https://knitmeshtechnologies.com/applications/heatshield-isolators/

ebay --> https://www.ebay.com/itm/123113435366?hash=item1caa21f0e6:g:ZJoAAOSwa9Fa61G L

Mc Master Carr site --> https://www.mcmaster.com/vibration-control-washers/extreme-temperature-vibration-damping-mounts-with-counterbored-unthreaded-hole/

hollandshielding site --> https://hollandshielding.com/Knitted-wire-mesh-washers-disks

ACS industries --> https://acsindustries.com/solutions/nvh/

Hope they are all flexible so you can easily take off from the sleeve.