So I searched for a while on the forum and couldn't find my issue.

I have a bone stock Evo 9 and it seems at lower speeds (5-20mph) there is some kind of rattle. Its kinda loud, but when I put the window down I cant hear it outside.

The sound it makes NEVER changes speed, meaning the rattle doesnt get louder or change pitch, or speed up. So to my knowledge its not a engine/drvietran issue.

It sounds the exact same as a bad CV axle when turning (old honda lol). But it usally happens during deceleration, (also happens when I accelerate but not as often). Doesn't matter if im going straight or turning either. It hasn't changed anything about how the car drive whatsoever yet and has been doing it more over time.

Any thoughts?

I did have the car on a lift and looked at the exhaust, all seems tight and clear.

 

Do you have aftermarket rims? In my case the people who put my tires on my rims forgot to tighten the valve stem nut on the inside of the rim. It fell off in the tire and made a weird noise at low speeds. Never at higher speeds past 25mph. Took me forever to figure it out, one day I took off the rims and heard it, bounced the tire a few times and sure enough I heard it

 

Haha great guess, but no these are the stock rims still.

I also dont seem to hear it when I first start driving (cold enigne) but maybe im going crazy. Any other thought?

 

I had this happen before it was something flying around in my back seat and I felt like an idiot... in my defense it was flying around where I couldn't see it

 

Ok an update, it sounds like a wood pecker. Weird I know. Maybe not as fast, but close.

 

Loose heat shield maybe?

 

I checked the exhaust on a lift and didn't see anything.

It doesn't sound like a rattle. Its more soild, like the woodpecker

I wish the stupid problem would just get worse and break whatever it is so I can fix it. Its in the "I want to annoy you as long as I can and make your car sound like junk" stage.

 

Haha been there done that! I had a similar problem where it just drove me nuts, it would also rattle at acceleration(sometimes). I checked the underneath of the car many many times an the sound wasnt like a metal to metal noise but turns out it was the exhaust hitting the cusco crossbrace, I fixed by using washers but later traded the cusco brace for the stock braces

 

I also recently started hearing a rattle coming from the back end of my IX that only happens during slower speeds, cant seem to figure it out and its buggin the hell outta me!

 

The rear diff supports make a noise in the back of the car for the last post btw, get a Buschur mustache bar and diff supports for the noise to go away. The OP you should put up a video of the noise otherwise there's no way we can help you.

 

This sound is coming from underneath, towards the front. With the windows down, I cant even hear it, (which is weird because inside the car it sounds like its outside). Im totally stumped.

It's not obnoxiously loud, but loud enough that every person asked me what is that rattle?

 

A video would be helpful.

See if you can get it on the lift again with it running, then you'll be able to hunt it down and if you can't pinpoint it you'll at least be able to get a lot closer.

 

It doesnt make the sound at idle, I put in every gear at idle and rev-ed it and hear nothing. Seems to only be 5-30 MPH. Ill try to make a video.

 

Have the wheels spinning while you are underneath it, you may need a second man for a driver.

 

Heres a video. The rattle doesnt follow the RPM whatsoever, so I really dont think its an internal engine issue.