KENNEDY

After reading that the new mufflers are quieter... I don't think I'm going to have the dealership replace the exhaust. Luckily my rattle isn't very bad.. it only happens occasionaly and only for a second or two. If it gets worse I may change my mind. Thanks for the info!

cruzmisl

I had the muffler replaced twice. The second and third mufflers were too quiet during normal use and sounded really weird past 5k RPM. When I took them off, they were full of water, so I wonder if there's a defect with them. The supplier changed 3 or 4 times so far, and my dad had the muffler replaced sometime in 2010 and his sounds fine. Only problem with it is that the drivers side hangs pretty unevenly.

I would have just kept the stock muffler. A rattle that goes away is way better than a muffler that takes away the VQ sound.

MIBeta86

Hey, did you ever find out? I have the same exact issue

GoBeau

Yes, I called a dealership and of course they said the warranty had expired - the guy was really nice and admitted that there were several muffler issues around those years (not sure if it's still an issue with newer models). Instead of replacing the system with OEM I went to a Stillen High Performance Exhaust system. Sounds really nice now and no more rattle just a nice deep sound, even better than the stock muffler system. I also added the Stillen Gen 3 dual intake system - it was a special promotion - buy the exhaust system & get the Intake for FREE. The deal was hard to pass up!

Maelstrom

Question on this. I just bought my 2008 G37S Coupe about 2 weeks ago from CarMax and it is having this issue. Would this be something they would cover under their warranty? I only have a 30-day warranty so I'll need to get this checked out quick.

Before I knew it was a "known" issue, I heard it when I took a test drive and they took it back to the garage to have it inspected and came back with some garbage about it making clicking noises when the AC was running. Since buying the car, I haven't been running the AC and have still heard the noise. I knew I should have gotten something in writing...

GoBeau

You'll be real lucky if they do warranty it, they'll probably tell you something like "what do you expect from an 8 year old vehicle". I installed a Stillen High Performance Exhaust system, no regrets. There's no way CarMax will install one of these for you. I would try to negotiate with them by letting them know the exhaust need to be changed by referencing these common issues. An OEM Infiniti muffler will be approx. $ 800.00 (get a quote from an Infiniti Dealership and bring it to CarMax). Try to get CarMax to refund you 1/2 of the cost to replace the muffler if they won't agree to replace it for FREE. Getting something back is better than nothing, right? Good luck, let us know how it goes.

Maelstrom

Thanks for the advice. I've got the service bulletin printed off to bring in to CarMax.

gogetter

iTrader: (1)

I had mine replaced. But now it doesnt seem as raspy or sound as good as it did before. I now wish I had kept the original muffler. If you can put up with the rattling for the first few seconds of warm up. I would just keep it. If you do get the new muffler. I will be glad to take your old one.

sprix

I got my 08 coupe from Carmax and also have the muffler TSB when starting up. I actually kind of like it... it really has a nice character when it starts up and then it quiets down quickly. Live with it if you can- it seems like those who go and get a different OEM muffler end up hating how quiet it is after all.

Twista

iTrader: (1)

I have a rattling noise that I hear when going over bumps. Sounds like a rattling tin can but this is the only time I hear it. I first thought it was maybe a loose heat shield. Can this be the same thing??

Maelstrom

Turns out I not only had the "vibrator in a tin can" rattle, but I also had a baffle loose in the muffler that caused some pretty awful rattling noises, so I don't think you want my old muffler .

Carmax is going to replace it for me. I'll post some before/after videos once I get the new one put on.

Rr1982

iTrader: (1)

Just bought a 2010 g37_XS Sedan.when I first start it, it sounds like it has an exhaust leak, after about a minute running it goes quiet,is this normal?

Kb Cool

Yes, it's normal they all do it!!!

Rr1982

iTrader: (1)

I'm used to an Audi, I thought I had some bad exhaust gaskets on this Infiniti.