I'm betting this has been covered ad-nauseam but I did some searching and could not find any posts describing what my car is doing. When I start the car, just after the engine idles down, occasionally I hear a quick rattling noise. It's been doing it for a while. My dealer kept the car for 2 nights and could not replicate the noise. Oddly enough, my father reports that his 03 Maxima does the same thing. Then last week I looked at an 07 Coupe. When the salesperson started the car, I again noticed it. Just to clarify, when I turn the key and the car comes to life, the revs will come up for a second then settle down to idle speed. The noise occurs just as the revs are falling to idle. It really sounds like 2 gears slightly grinding or a piece of metal that is loose, rattling around somewhere. Am I going crazy?

 

If you can feel some vibration on the brake pedal, it is the ABS self-test. It sounds like a rattle.

 

I thought this occured when the car is in motion, at very low speeds. I can feel that happen when I get rolling, I'm fairly certain this is something different...happens only when the car is stationary, just after the starter disengages the flywheel.

 

Are you sure it is not some back pressure in the exhaust causing a rattle in the cats or maybe even flywheel chatter?

 

It's caused by a little slack in the timing chains before the tensioners pump up with oil.

 

i've had it happen once...never again, but i know what you mean.

 

Ah...that would make sense. This would explain why it only happens when the engine is cold. Can you tell how you found this out? I ask because even my Infiniti service dept. was unable to tell me this.

 

I honestly don't remember if I read that, if someone told me that authoritatively, or if it's just my educated guess, but that's what I think it is. The link posted by Treacherous looks like it's describing a similar phenomenon, too. Mine (04 6mt sedan) only does it occasionally, and I think I understand what it is, so I don't consider it a problem.

 

Well either way, thank you very much! I originally thought the starter gear was hanging up on the flywheel and was certain I would be stranded some day. I feel much better now.

 

dang i have the problem.. but i guess it isn't really a problem.. it happens about twice a week

 

my maxima did this ... it was the timing chain ... did it when I was low on oil, had dirty oil or on a really cold morning ...

it goes away after a while.

I've heard it once on my G as well.

 

I don't know about our G's but this sounds like the starters bendix drive not releasing quickly and getting hung up a little before it recoils back into the starter housing! Just my 2 cents

 

So my sound is a small exhaust leak at the manifold. As soon as the car warms up a little it expands and goes away.

The motor is coming back out in a month or so anyway.

 

Yeah, keep rubbin' it in why don't you

To the OP, sorry for getting of subject. This is an interesting issue. I never noticed it. Although, now I'll probably notice it in the morning.