I searched for this but really couldn't come up with anything definitive. I hope I am overreacting. 09 Sedan with about 800 miles on it and it seems that it is louder now when first started up cold as in overnight. I start it up in the garage so it probably echoes a bit too. After about 15-20 seconds when the idle rpm's come down it gets quiet as a mouse. I just don't remember this when I first brought it home. It isn't really a ticking or a valve train noise I don't think but is sounds like the exhaust has more growl to it for a bit but only on cold starts. Call me crazy but is this just my imagination or normal for this car? I am gonna raise the hood and jump out of it real quick to listen tomorrow but it goes away fairly fast.

 

Yes this is normal. It idles higher and is louder until it warms up. I think it had something to do with warming up the cats quicker.

 

Normal...the VVEL is loud when cold. PLUS...its the position of the VVEL and not the idle speed. If you touch the gas...the rpms will jump up but the noise instantly goes away...then as the rpms come down to 1200 or so again...it will come back as the VVEL adjusts again. You could use the Nissan Ester Oil (super expensive) but the sound goes away and if its not harmful then I don't care. As you noted, it only lasts for 15 seconds or so.

BTW: To test my theory above...DON'T give it much gas if you care about racing a cold engine. The throttle is ultra sensitive when its at high idle....just tapping the gas will jump it up to 2K rpm's!

 

Thanks guys. Yeah I was hoping that it was normal. This is the first Infiniti I have owned but owned a couple of Nissans and never noticed this before on ANY car actually. I might try out your theory once just to see but just be very careful as stated.

 

first car i've owned that's done this. i noticed it on the test drive. i don't think it's louder, i think it's raspier.

 

I'm not sure what you mean by raspier (a term normally associated with exhausts)...but its most definately valve noise.

 

Normal. That is the the demon in the car trying to get out. The magical barrier keeps it at bay though.

 

What's the magical barrier? Nissan ester oil? I did change the factory fill out with Pennzoil YB but I might go back to the ester oil for the break in and go synthetic after that. I always change the factory fill out at about 500 miles in and run dino for the break in though. Just my ritual. I will see if it helps quiet the drive train down some.