OK folks I've got a weird issue here. I have a pretty intense rattling on very cold weather start ups. I did a little searching, couldn't find anything that matched my problem.

It's only when the car goes from cold, to running temp, then the rattling stops. I'm wondering if something is loose somewhere under there? It sounds like it is coming directly under my seat. I'll try and explain this as best I can. It sounds like the rattling...matches the tempo of the cars idle? If that makes any sense. Any ideas?

A couple of notes..
-Haven't been directly under the car yet, only peeked and poked around, couldn't see anything
-No CEL


I can post a video of it later, I don't have time right now.

Any help is appreciated. Thanks

 

Could just be normal transmission chatter...if youre not used to it it may lead you to believe your car is broken. Our transmissions even when stock tend to be a bit loud.

 

exhaust, heatshield?

 

If the sound is coming under your seat it sounds to me like exhaust related.
In cold weather,heat shields,cat parts contract.Warm up it tends to go away.Get it up
on a lift when its cold.Another rattle that is overlooked at times and people look elsewhere is injector noise.This varies by vehicle.Engine covers mask this "ticking"
many times.

 

I'm leaning away from transmission chatter as it is quite loud and I have a JWT lwf/clutch I recognize those noises.

This is what I'm thinking.

Here is a clip of the noise, again, this noise completely goes away once the car warms up.


-if you have a subwoofer turn down the bass and you'll be able to hear it better. this clip didn't quite fully capture the sound.

 

I didnt realize you were modded. When I had HFCs the driver side would rattle on the heat shield intermittently which I had to bend out of the way, so a possibility.

I dunno, the sound doesnt really sound like a head shield rattle to me. Mine sounded more metallic.

 

Get it up in the air and get your head in there.