coolraz

Hi guys,
I've had my setup since May. Everything going ok but now I am getting what sounds like an exhaust leak. It's kind of a rattling sound when it starts up, then as it heats up (and I assume the metal expands and seals the leak) then it's a lot less loud.

You can hear the sound in this clip. It's really noticeable at startup. note how when I rev it, the sound kind of goes away and is replaced by the regular (oh so sweet) sound.

Dunno what to do (Im taking it to a shop soon, but work schedule is tough so it wont be a for 2 weeks)

I love my car but right now it sounds like a friggin open hood chevy lol.

<iframe width="420" height="315" src="http://www.youtube.com/embed/g-wuXL27_Tw" frameborder="0" allowfullscreen></iframe>

Staples

iTrader: (9)

It very well could be an exhaust leak. I use a little bit of high temp RTV silcone sealant around the gasket as an extra precaution so it doesn't eventually leak if the gasket gives out. The other thing it could be is the fact that stainless steel has a tendency to cause resonance throughout the exhaust which can cause a loud metallic sound on cold starts that resembles an exhaust leak.

What kind of exhaust components do you have?

It looks like Fast Intentions resonated test pipes, but I'm not sure.

simonsez

sounds like a leak/hole in your exhaust system.
I've had the same exact sound like that before.

mikeb2004

I have the exact same sound on my '11 G37 coupe on cold start, since brand new.

Consistently goes away after about 10 seconds, like someone just turned off the sound, and then never comes back until the next cold start.

I just figured it was the secondary air pump shooting air into the cats, (???) or some other sort of emissions stuff to get the cats fired up quickly.

coolraz

I thought about the cold start thing, which I had noticed before. The cold start was more of a higher idle rev in my case so it was noticeable but wasnt really a different sound. This started recently and actually a few weeks ago tempereatures were a lot lower than now, so if it was just a cold thing, it would have been more noticeable before I would think.

I have FI CBE and High Flow Cats. But they do sound more like TEST PIPES with this rattle lol