Exhaust noise on startup with 3.7 V6

[mikedamageinc]

I know there is the famous timing chain noise for the V8's so this is obviously something different. It seems to be a big issue with the G's and Z's since I saw a lot of threads about it on their forums but no M's have reported it. This isn't my car but mine sounds exactly like this, sounds like its leaking for 10-20 seconds then just goes away. As long as its not a danger I don't care except it make the car sound like a piece of crap and I don't want to be that guy with "a nice car but can't afford to fix it." Many people say its the muffler but some have replaced them and the noise doesn't go away. Who else has this??

[Ilya]

I've actually noticed this on my 07, haven't noticed it on my 11 although I haven't specifically tried to hear it...will try next time I'm by the car. I also noticed this on my 99 Maxima. I always thought it was normal as a result cause the exhausts I had on those cars were done by me and done well (I go overboard on small details like gaskets, sealant, etc.). No way in hell I had a leak.

I actually always thought it was the EVAP system or something releasing pressure to be honest but never really looked into it.

[M37xfan]

I believe the noise at start up deals with the direct injection. Once the engine reaches operating temperature it should go away. My M37x does the same thing. I have noticed that in warmer temperatures it is not as noticeable

[mikedamageinc]

I believe the noise at start up deals with the direct injection. Once the reaches operating temperature it should go away. My M37x does the same thing. I have noticed that in warmer temperatures it is not as noticeable

3.7 is not direct injection

I've actually noticed this on my 07, haven't noticed it on my 11 although I haven't specifically tried to hear it...will try next time I'm by the car. I also noticed this on my 99 Maxima. I always thought it was normal as a result cause the exhausts I had on those cars were done by me and done well (I go overboard on small details like gaskets, sealant, etc.). No way in hell I had a leak.

I actually always thought it was the EVAP system or something releasing pressure to be honest but never really looked into it.

When you did your own exhaust, are you talking aftermarket, or r&r the the stock pieces?

[Ilya]

I believe the noise at start up deals with the direct injection. Once the reaches operating temperature it should go away. My M37x does the same thing. I have noticed that in warmer temperatures it is not as noticeable

3.7 is not direct injection

I've actually noticed this on my 07, haven't noticed it on my 11 although I haven't specifically tried to hear it...will try next time I'm by the car. I also noticed this on my 99 Maxima. I always thought it was normal as a result cause the exhausts I had on those cars were done by me and done well (I go overboard on small details like gaskets, sealant, etc.). No way in hell I had a leak.

I actually always thought it was the EVAP system or something releasing pressure to be honest but never really looked into it.

When you did your own exhaust, are you talking aftermarket, or r&r the the stock pieces?

On my Maxima and 07 M35x, it was after market/performance exhausts. Unless I'm confusing the sound on your video with what I heard...

[Frog]

To me it sounds like a manifold gasket and as it warms up seals the small hole ? What do u all think. I have the same sound on my g37

[Mjkkb2]

To me it sounds like a manifold gasket and as it warms up seals the small hole ? What do u all think. I have the same sound on my g37

Wouldn't it trigger the SES light if it was the case?

[mikedamageinc]

Dealer has my car, cold started twice and said they didn't hear it. Funny thing is, the fx (q equivalent ) they gave me a ride in was making the same sound constantly and the Mechanix was telling me they replace a lot of exhaust systems for that sound at a several grand a pop, usually under warranty. I will just like with the noise if warranty doesn't cover it, or an excuse to go full aftermarket!

[lovemycarM35]

my M37 makes the same noise at cold start then goes away in like 10 sec it's normal they all do it i had a G37 loaner makes the same noise at cold start up. i just call my dealer it's normal it has something to do with valve train, a bunch of tech stuff i didn't understand

[Altered]

I do believe the sound is caused by the valvetrain as it does seem like its something with variable exhaust timing. It didn't sound like a leak when I had test pipes on the car, it would just idle really loud during cold starts. But you notice as the exhaust leak sound goes away that the idle RPM hasn't really changed.

[mikedamageinc]

Yea my dealer said the same thing, valvetrain timing at startup. Really sucks that noise has to happen, I think it makes it sound crappy, funny that guys on other forums say they like it. Maybe on a drag car but not my luxury family car! I bought the car in DC so they had to bring the car around so I didn't hear it at startup, my fault for not investigating but I figured a certified preowned from the dealer would be good to go. Even though this isn't an actual problem there were other annoyances from them...