That's cool, and probably what you should do. There was no guarantee my shade tree mechanic quick fix trick would have helped anyways. But i feel your pain on that aggravating noise and figured it wouldn't hurt to throw it out there.

 

Just a question.

I'm currently shopping for a CPO G37 and I notice this post. Is this issue only found in the '08's?

 

ill say this, i just bought an 08 and i'm starting to hear one of mine going bad.... all the 37's use the same cats so im not sure if its just the 08s. it all depends on the car. Some cats go at 60k some last up to 100k it all depends on the car itself. It something to check out tho... the cats are about 7 bills each... So im not going to say when your looking at any G make sure you slowly rev the engine and listen for that knocking rattling sound.

 

man this is THE most annoying thing without a doubt, if theres one thing i dont like about my car is the cold start up the exhast rattle is louder than my exhaust itself lol its really emberassing to myself.. people see a high end car (my infiniti) and then hear this really bad noise coming from the exhaust it sucks. i read over this entire thread alot of useful information i think im going to find an OEM 370z exhaust and replace it with mine i see that would work and im down for that until i come up with 1400 for the aftermarket one i do want lol thanks for the info you guys

 

Here's the official TSB for the Muffler rattling noise. I would print this out and take it to your local dealer.

Also the link: http://www.infinitig37.com/TSB/1SB19.pdf

 

youre the man lol what happens after i take this to infiniti? they just fix it or i still gotta pay for it myself? lol

 

I don't think TSB's are free. If you're car is still under warranty I'm going to assume that they should be able to fix it free of charge.

 

I got the same issue but more towards the rear of my car. Sounds as if mine is coming from the muffler but I couldn't find the issue. Mine sounds if there is a spring or something just vibrating against the muffler. Doesn't seem to be an issue though, just extremely annoying. Just take the opportunity to upgrade your exhaust

 

On 2008 G37's the mufflers where stamped together and not welded so after time they would start to rattle the only fix is to replace the muffler if you have warranty they will replace it if not you can replace the muffler off of a newer G37. There is a TSB on this issue with what vin are affected.

 

I just bought a 2010 with 54K miles two days ago, and the rattling started yesterday! So it is also with 2010s as well

 

This is a four-year old thread, but okay. AWD cars are especially prone for heat shields to rattle. You don't say whether yours is AWd or RWD, but look there first.