Exhaust System Rattle

Rodeo, 2000, 3.2L V6: At 1800-2000 RPMs there is a rattle in the
exhaust system. It sounds like a lose heat shield, but the truck has
been up on a lift to check heat shields and none are lose. When
driving with another person and the passenger wondow open (the
passenger can really hear the rattle), it seems to be from the area of
the cat converter or a vibration in the passenger floor. Also when
tapping the exhust pipe around the cat converter it sounds as if
something is lose or free inside the cat converter. A mechnic has
suggested that the front exhaust pipes maybe double wall construction
and the inner wall has broken free from the mounting point and is
vibrating.

Note: Mileage is 98K

I had a similar problem on a Toyota. My mechanic used some chemical to
"de-carbonize" the exhaust system. Sorry I don't know what it was or how it
was applied.

Because you hear a noise near the catalytic converter, it may be the cat
itself. I don't know how modern cats work, but the ones from the '80s had a
small platinum wire that was the catalyst and they could come loose at one
end. As it is an emmissions related part it may be covered under warranty
even if the rest of the vehicle isn't. Thought 6 years and almost 100K
miles may be beyond mandated emissions warranty.


"SRODEO" <PRC8117.DeleteThis@AOL.COM> wrote in message
news:1149017096.034024.278890@i40g2000cwc.googlegroups.com...
> Rodeo, 2000, 3.2L V6: At 1800-2000 RPMs there is a rattle in the
> exhaust system. It sounds like a lose heat shield, but the truck has
> been up on a lift to check heat shields and none are lose. When
> driving with another person and the passenger wondow open (the
> passenger can really hear the rattle), it seems to be from the area of
> the cat converter or a vibration in the passenger floor. Also when
> tapping the exhust pipe around the cat converter it sounds as if
> something is lose or free inside the cat converter. A mechnic has
> suggested that the front exhaust pipes maybe double wall construction
> and the inner wall has broken free from the mounting point and is
> vibrating.
>
> Note: Mileage is 98K
>