Hopefully someone else has this problem, and has diagnosed it.

I think maybe a heat sheild is loose or something. At certain rpms / engine load the car hits the right frequency to cause a buzz / rattle from underneath. It sounds "tinny" so I suspect a heat sheild.

Anyone else have this problem, and knows where to look? I put the car on ramps last weekend and tried to find it, but no luck.

I'm hoping it is not something in the engine.

Thanx in advance,
Chrisbert

 

It's probably the ports opening up. SOunds kinda like a tinny rattle? Some people call it a bell like sound. To me it's more like a butterfly valve rattling.

 

I sometimes get what I would qualify more as a rumble type vibration when the engine is under a certain load around 4000 rpms.Started after muffler and mid pipe replaced after an accident.Dealer technician felt it but couldn't find a solution yet... If he does I will contact you...

 

Thanks. It is a tinny sound, and seems to come from the right side through the passenger floorboard area. It is annoying as heck and sounds like a Yugo when it happens.

It started happening shortly after I had the dealer replace the oil pan and rotate tires. That was what had me believing it was some sort of metal plate that was left loose.

 

And, I always use 91 octane.

 

I had the same noise and found it/ fixed it. At the back of the transmission (underneath of course) is a black vibration dampener
that is making contact with the trans and causing the noise. It will bend out of the way easily and the noise will be gone.
You can find it by getting under the car when it is cool and tappiing on the catalytic converter (see why I said when the car is cool?) with the heel of your hand. I was able to duplicate the rattle by doing this and it led me to the dampener. Situation solved.

 

Thank you PoMan; that is promising news. I figured it was something like that, but my time under the car was when it was hot and I wasn't getting anywhere near the cat then. I'll go at it next weekend so I can let it cool on the ramps. The paradox of having to warm it up so it won't flood and letting it cool to work on it. :-)

 

Well, I got under there but didn't see the black dampener. I tapped around on some of the heat shields with the handle of the screwdriver but couldn't hear the noise. I had the car on ramps, and it is really creepy being far enough under the car to reach that area. I was under there with my chest touching the car thinking how bad it would suck if the car moved. Of course, with the parking brake on, the wheels chocked it ain't going anywhere, but its a nasty thought.

 

It sounds like exactly the same sound I've heard not only from the test drive car but also the one I now own. Handy piece of info you shared PoMan! Thanks!

 

Well, now it stopped doing it on its own. Possibly, since I think it is the piece that is in the latest recall, it fell off. I'll have to look at some of the cars I share the freeway with and see if they have my heat damper stuck in their grill.