https://www.myg37.com/forums/engine-...-start-up.html

Sounds like you're experiencing what I and a few others had been... although I think I am the only one with a replaced engine (after the BBB intervenes). I have another appointment with an Infiniti Tech/Specialist tomorrow. I am getting really close to doing a Lemon case. If anyone considered this noise to be normal, they're goofy.

 

I heard this noise when I went to test drive a G37xS. I'm guessing it's normal because when the dealership took delivery of it the same day, I heard it.

 

This just in from Infiniti:" As a result of the overwhelming support of G37 owners with rattling and clanking engines, all non-clanking and rattling G's will be immediately recalled and the rattle and clank install TSB will be performed at no additional charge!" LOL

 

That's funny. If Infiniti markets it as the latest "mod" they'll make
a fortune from some of the guys on this site. ....the same ones
who will wear out their engines in 50K and believe it didn't
have anything to do with the oil they use or the noises coming
from their engines.....damn Nissans

 

^^ Easy solution - lease. Do the required maintenance and then let Infiniti worry about it.

 

As a long-time resident of this northern outpost, I have grown accustomed to the odd noises that machinery (and sometimes men) make in sub-zero conditions. My 09 G37xS sounds loud for about a minute on a cold start. I would not describe the start as "rough" (no undue vibration, no engine stuttering/misfiring, etc.) but rather noisy. Like clockwork, the noise subsides as if someone (something?) turned a switched on or off. While this is happening, I have noticed some brief dimming of the interior light, if it is left on, indicating a relay or two engaging or some other such electrical event during the initial startup. Perhaps there is some computer-controlled engine management event occuring during a cold start related to emissions control? It is not something that I have any concern over whatsoever although I would appreciate a technical description from someone in the know about what our engines are doing during the first minute or two of a cold start that could account for the abrupt change in sound.

 

Change to a lower viscosity oil for the winter, at least 5W30. Take a look at the oil that came from the dealership when its below zero compared to 5w30 or 0w40 (if the G can use it, speaking on other mechanical experience) and you'll know why it's a rough start.

 

FWIW - After I posted in this thread, I watched the video of one poster who was concerned about the noise at "cold start" and the car was in his garage (with the door open) and he was in his shirt sleeves. I don't think what he was talking about is related to our really cold temps.

 

My mistake, I just noticed a few posts about low temperatures which in turn most likely is too thick of oil.

 

Funny i run 5w-30 all year and see temps dip to -40 C and lower and do not have an issue.

 

Happens to 370Z guys too:

knock on startup - Nissan 370Z Forum

 

Noticed the noise on my G37X too, with about 200 miles on the odometer @ about 32F

 

My wife just bought an '09 G37x and we've both noticed that it has a rough/noisy cold-start sometimes. (I'm not the primary driver, so I don't know if it's every morning... I should ask, I know, but I'm reluctant to concern her just yet.). Now the thing is, our garage is insulated and seldom drops below 50 degrees F. So, I don't see how thinner oil would help. Besides, I think the book recommends 5-30 and I assume that's what's in there now at just 1,500 total miles.

My Question to y'all is this, "What should I tell/ask the dealer?" And when? I can't imagine it's serious, but I don't think I've ever heard such a loud cold-start before and I've driven lots of cars. It settles down fairly quick after, mmm, maybe 15-20 seconds? I see the techno-dweebs have rung in on this forum, but I don't think I'd get a desired response if I try to quote "some dude on the internet" to the Service Manager the first time I speak with him. Any thoughts on strategy? I really don't know much about engines - I just change all fluids early on my cars, replace stuff when it's showing signs of wear and keep new plugs in every 30-40k or so (platinum). (I got 190,000 trouble free miles out of my little Saturn doing this and was hoping to get the same or better from the Infiniti.)

 

is the engine loud or the exhaust. When I had my stork exhaust i was louder on cold morning. Now with my after market it is super loud.

 

Mine does the same thing for about 10-15 seconds and then its ok. If I drop it in gear right away it stops. Sounds louder when in garage. Not coming from motor sounds more like an exhaust sound. Live in So Cal so its never really cold. 2009S with 1500 miles