Metallic rattling coming from undercarriage.
 

Hi,

I have a 1990 Acura Integra GS, auto transmission with a DOHC engine, front wheel drive. I recently ran over a parking lot median trying to avoid another car. The two front tires went over the median and it kind of came to a stop resting on the front undercarriage. Luckily the wheels were still on the ground and I was able to back out, however it scraped and banged up the underneath quite a bit. This was about a week ago. Today, the car started to develop a loud metallic rattling (kind of like a bunch of pennies being thrown at a metal fan) which is coming from underneath the car, exactly where it was scraped up. The rattling noise only comes at around 1750 - 2250 rpm when decelerating or accelerating. Sometimes it doesn't rattle at all, or very quietly, and sometimes it rattles a lot and loud. Makes the same noise whether it be in neutral or in gear. It definitely was not there before. Any ideas? I'm not really good with cars, so layman speak is appreciated. Thanks.

i think its the heat sheild hitting something or something with the exhaust system hitting something. my car does it too. try holding the exhaust with your shoe and it should stop. easy fix i know if you take it to the shop,

if someone can input with a diy, itd be good...

i agree with drift_n_shift, chances are its the heatshield from the cat, any muffler shop should be able to weld it back or just remove it

get underneath the car and look, why would you ask questions before you did that? afraid to get dirty?

yeah it is most likely a heatsheild or possible exhaust hanger or bracket. Like everyone is saying just get under the car and move the exhaust and make sure the heat sheilds are secure.

my dust sheilds on my rear discs were making that same noise.. annoying. but agreed, heat sheild for sure. very inexpensive.

worst case senario baffles in the muffler or catyltic breaking down. I had the honeycomb completely seperate from the cat housing.