Vibrating/resonating tailpipe

I have a '99 dodge dakota that recently had the catalytic converter and
exhaust pipes replaced.

I'm now getting a strange resonating sound between 30-40 mph -- It
sounds like someone blowing across the top of a pop bottle. The sound
stops when you let off the accelerator. It's definitely coming from the
back of the vehicle. I crawled under the truck and inspected the
exhaust but could find no place where it might be vibrating against the
truck body. If I had to guess, I'd say the tailpipe was vibrating at
such a high rate of speed when traveling 30-40 mph that it begins to
resonate like some sort of musical instrument.
Does this make sense and if so, what can I do about it?

Thanks

On Wed, 19 Jan 2005 wrote:

> I have a '99 dodge dakota that recently had the catalytic converter and
> exhaust pipes replaced. I'm now getting a strange resonating sound
> between 30-40 mph

Who replaced the catalyst and pipes, and with what?

The dealership replaced the cat because it was a warranty repair, so
I'm assuming they used a Dodge cat. The pipes were done by my usual
garage, but I don't know any more than that.

I can tell you the pipes (from the cat back) were done first, because
the garage wouldn't touch the cat until/unless they were replaced
because they were in bad shape. So the garage did the pipes first, and
there was no problem. A few days later, the cat was replaced and then
the sound started.

wrote:

> I have a '99 dodge dakota that recently had the catalytic converter and
> exhaust pipes replaced.
>
> I'm now getting a strange resonating sound between 30-40 mph -- It
> sounds like someone blowing across the top of a pop bottle. The sound
> stops when you let off the accelerator. It's definitely coming from the
> back of the vehicle. I crawled under the truck and inspected the
> exhaust but could find no place where it might be vibrating against the
> truck body. If I had to guess, I'd say the tailpipe was vibrating at
> such a high rate of speed when traveling 30-40 mph that it begins to
> resonate like some sort of musical instrument.
> Does this make sense and if so, what can I do about it?
>
> Thanks
>
Heat shield?
Judicious application of a high mass alignment tool shoud do the trick..

--
Paul
'91 XL1200
'77 GL1000 (W.I.P.)
"I feel more like I do now than when I got here"

On Wed, 19 Jan 2005 wrote:

> The dealership replaced the cat because it was a warranty repair, so I'm
> assuming they used a Dodge cat. The pipes were done by my usual garage,
> but I don't know any more than that.
>
> I can tell you the pipes (from the cat back) were done first, because
> the garage wouldn't touch the cat until/unless they were replaced
> because they were in bad shape. So the garage did the pipes first, and
> there was no problem. A few days later, the cat was replaced and then
> the sound started.

Sounds like you have an argument to make with the dealer.