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Rattling Cats vs. Rattling Heat Shields - How can you tell which? - Induction/Turbo/Manifold/Exhaust - The Lotus Forums #ForTheOwners Jump to content

Rattling Cats vs. Rattling Heat Shields - How can you tell which?

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Can someone please advise on the difference in sound between a rattling cat vs. a rattling heat shield on a V8? Better yet, can someone please post a picture of heat shields on a V8, so I know where they are?

I have a rattling sound -- sounds like marbles in a can -- and I'm thinking it's the $$$ cat that needs to be replaced. I'm going for aftermarket high-flow cats. But I don't want to spend the money if it's just the heat shields.

Thanks in advance!

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there are small metal rings (those should hold the catalyst monolith in place) who sounds like marbles if the catalyst is fully hollowed out. Just undo your catalysts -shake them, an if it sound like sand running on a plate there is still some of the ceramic substance in it. Bud that 'powder' is useless for you. Look from behind or into the o2-sensor holes and try to get the rest of it out.

Than you will have *free flow* pipes :)

As others have said : The heat-shields on the exhaust manifolds are mostly bend and broken by the different heat behavior of the exhaust to heatshield material. So those will not exactly rattle like 'sand/marbles in a can'.

here you can see what i have done now on both sides, the small black metal rings are original. I have replaced the rest of the ceramic monolith with some internals of after market 'race type' metal catalysts .

just cut the end of OEM and universal-fit aftermarket parts off, reassemble it all and weld everything in place.


Edited by G


to name the things if I see them, that's what I call integrity..


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