Rod Bearings or Bad Cats??

[RTStabler51]

I am officially confused.

I thought my SHO (119k) was knocking. Took it out last night, and it would only do it for a split second at about 4k. Then today, some times around 2k it would 'rattle'. So its not really consistent. Then I was thinking...maybe bad cats?? I know Prophet78s car did that, and I heard it and i swore it was bearings, but came to be just the cats.....

I'm gonna pull the ypipe off this weekend, and check them out. If they are bad how do you know?? Dust & stuff comes out???

 

[SilverSHO]

Yes, you will see dust come out of the Y-pipe, if I remember correctly. I know I saw it in mine. Of course, I found pieces of catalytic converter material in my OE mufflers, which confirmed that my Y-pipe was bad.

 

[91 SHO PLUS]

RTStabler51,
I think what you're hearing is a loose catalytic converter heat shield making a "rattle" sound. When the engine reaches certain RPM's, the loose heat shield will vibrate against the converter! Sounds like a good time to install a Performance Plus Y-pipe! thumbs_u
Good Luck,
Jeff

 

[91 SHO PLUS]

New Sig Check! shoot

 

[sdpatt]

To check the cats and the heat shields, just lightly tap them with a wooden stick. If you hear loose parts then you found the source of the noise.