the issue is not the cold start noise. its the fact that no matter how much you drive or how warm the exhaust gets the noise does not go away. I can drive for an hour straight get out of the car and go to the rear and the noise is still there.

 

ahhh interesting. I get it. So the cold start throaty rumble for 15-20 secs when turning her on is normal but many of you are experiencing a metal clanging/rattle every second the car is on? But I thought some of you were mentioning it goes away when the car warms....? Or does it just get better?

Anyhow I dunno why this exhaust thing is happening in some cars....I wonder if Im not driving my car hard enough to get it lol. Cause if mine is in remission I want it to come out so I can fix on warranty...

 

my sound does not go away. and if you have the broken exhaust issue it should not go away for you either.

 

Joe,

the throaty rumble and roar is normal, I had a horrible crappy tinny noise that also went away like the throaty rumble. the master tech said he'd had a few in and it was a baffle issue. BTW I love the throaty rumble!

 

Had the same problem on my G. on cold starts my muffler would rattle like krazy. took it to the dealer and they replaced my muffler. now sound is gone

 

+1

Same thing happend to me. Definately get it checked out...

 

Are you running thicker than required oil? The rattle is most likely valve or lifter tap. If it goes away and it's under the hood then I would not worry to much as it is going away because oil is making it's way up through the heads. You need to open your hood on a colder FL morning, have your wife stat your car and listen right over the intake plenum. Sometimes exhaust rattles can be transmitted up through the mani's and sound like they are coming from the engine. If it is lifter or valve tap then you will hear it at the top of the engine. If it goes away it is not something I would sweat as even if their is something detrimentally wrong with the engine, it's guaranteed for awhile. If it persists and gets worse, tell Infiniti you want them to document it just iin case, later on a issue shows up with a rod bearing, excessive valve wear, bad guides etc.

Ok, just checked and they are hydraulic lifters. Notorious for some early startup rattle noise. Have heard them so bad that you would swear you had rod knock.

 

I think i was one of the first, if not the first on these boards to have this issue.
Got the muffler replaced, problem was corrected. Now... a good few months later the horrible sound is starting to return. Gonna nip it in the bud this time and call them right away.

>_<

At this rate i should just ask for an aftermarket axleback exhaust, or the optional one they get over in Japan for the 370 GT

 

if u run a low octane in the car it can make a noise like that

 

perhaps.

nuthin but shell V power for me 93 all the way

 

yeah 93 is the best to run in all infinti's

 

good thing cali sucks ***** and i have to run 91 MMMM RACE GAS!

 

Sounds like one of 2 things: piston slap or 'collapsed' lifters, since they're hydraulic indeed. It's very hard to tell them apart: same rhythmic (and loud as heck) 'clak, clak, clak', but lifters 'pump up' rather quickly, whereas piston slap usually takes 10 to 20 seconds to go away, as piston(s) heat up and expand. The good news is neither one reportedly causes any damage, even in the long run. My F150 had piston slap, and Ford offered to rebuild my engine at no cost, but I refused since it happened just a few times a year.

My '06 LS2 GTO had that nasty noise twice when new (there were 4 clacks each time), but it didn't happen this winter, even though it was colder. And yes, these engines are legendary for piston slap, but I don't think mine has it due to the fact it doesn't go away (AFAIK). But I'd gladly trade 10 or 20 seconds of noise for the constant hot valve clatter of this engine. Heavier oil helped (5/40 vs 5/30, due to mild winters and brutal summers), but it's still there.
I can't stand engine noises either, but after listening a cold G37 sound very 'unflattering' as well, am getting used to them before I go nuts. Good luck.
JC

 

baffles in the muffler gone bad. Remedy: New muffler

Are there any Axle-Back exhausts out there? Or just CAT-Back

Hmmm, *searches*

 

This is exactly what I'm thinking. It stops after 20 seconds at most once everything gets heated up and lubed. Just really annoying. People walking their dogs look over like WTF? I had my dealer tell me that most G37's do this on startup. It's a lease and under warranty, so what the hell. I'll live with it until it blows up or something.

I also had the muffler rattle issue and had it replaced. That took care of the tin can in a garbage disposal noise issue but not the cold startup noise.

Overall though, I'm still happy with my car. It's a blast to drive.