So I just got a 2008 g37 sport coupe on Monday, loving it so far. The only thing I have noticed is when I'm either parked or just idling there is s rattling sound from near the mufflers. It sounds a little different from the exhaust rattle videos I've seen and goes away when I rev the engine as well. Is this how it starts or could it be something else?

 

if it happens at idle. i would just idle the car and take a look down there to see what is happening. it could be an exhaust hanger is loose or maybe a heat shield is loose or hitting something.

 

So apparently it's inside the muffler. Washed my car today and a buddy of mine checked it out. Any idea of what it could be?

 

Maybe a rock or pebble got in there?

 

I have a similar problem with my 2008 G37s and a very knowledgeable Service Rep said it was a loose baffle in the muffler. A new muffler is very expensive so he suggested just living with it.

 

There's a recall or tsb on 08 mufflers coming apart inside...

 

Just about all 2008's had the rattle in the muffler. The baffles were improperly welded and literally just popped apart. There was a TSB regarding this which called for replacing the muffler. For a 10 year old car the best bet is to just:

a) deal with it;
b) replace it with a new OEM for around $700;
c) replace it with a newer/used from eBay for around $200, or;
d) upgrade the exhaust entirely.

 

Thank you for the information.


I have been living with it but am wondering if the loose baffles can move, restrict the exhaust flow, and reduce performance.

 

I would either buy a used OEM if you want to keep stock. Check for sale section here and also ebay.

Or just get an aftermarket. i don't think you need a full CBE so just get an axelback. If you live in a dry area, just get a topspeed. It's only $300.