I have a 99 gs300 and while accelerating from a stop or low gear i hear a weird rattling noise from the bottom of my car but it goes away when i hit like 30-40mph. My gs has 134k no engine lights or anything. Any ideas?

 

Sounds can be a million things its hard to diagnose without some sort of audio/video clip. Rattling to you may be 'clanking' to someone else

First thing that comes to mind is possibly just a loose exhaust shield. But again, hard to make a good guess without something to hear

 

I have a 99 with 186k I just bought and every day the rattle is getting louder. Almost sounds like a lose heat shield or something. If I figure mine out, I'll post it up. It only happens under very light acceleration and then it goes away or I just can't hear it over engine/road noise

 

It a loose heat shield. Would bet on it

 

I had a similar sound that got worse and sounded like a rod knock. Thought the engine was done. Turned out to be a cracked flexplate. We had the car up on s lift and you could hear it coming from the rear nspection hole.

 

Got mine figured out, had a small rock in between one of the heat shields and the exhaust