So recently i noticed when my 2013 evo x (5500 miles) is cold, there sounds like a rattle from the back portion of the car. I say ita the rear end because it sounds almost metal on metal, and when i rev it while cold it rattles more. When i start driving, about 1 minute or less of and it goes away. Ideas? I might just have mitsu look at it. Thanks in advance.

 

Drop it off in the evening so they can look at it while it is cold in the morning.

 

Why not start it cold and go to the back of the car and listen for the rattle? Is it inside or outside? Pin point it, and see what is causing it.

 

My guess is something on the exhaust. On my 2011, one of the heat shields towards the back of the car was loose, it would only rattle when cold, and the rattling increased with throttle, until the exhaust warmed up ~5 minutes. Once warmed up, the exhaust would heat up, expand, and the rattling would go away. Just a thought.

 

Had the same... then it was gone. I have aftermarket exhaust though. Never located it.

Things to check:

1. On stock exhaust exhaust tips have some space between them and the pipe - you could have some stones stuck in there - I know I did. Pita to get them out.

2. Right where the muffler is, over it attached to the underbody there is a heatshield - while car is still cold and idling - grab it with your hand and see if it helps.

3. Check your license plate - that could be the culprit.

 

I would suggest checking the heat shields along the exhaust. I had a rattle on my 2010 that went away when I replaced the exhaust.

 

Thanks for the replies, ive come to learn its not while cold but when driven then parked and cooled down, then started again. So like a partial warm start. Ive havnt had time to take it to mitsu since its like a 45 minute drive and i would rather take it to my tuner first probably. Thanks for the info tho guys i will get it sorted.

 

I've had a part of the exhaust heat shield come off and rub on my driveshaft. Very disturbing sound. I just pulled it off.