check your belt tensioner and idler pulleys. spray some lube on the pulley and lube before starting up when cold. if noise is not there replace the tensioner and idler pulleys thats making the noise.

 

I have the same exact noise, in which its only at cold start up as well. So were going between a starter and pulleys basically? What would you guys lean towards the most? I'm going to get some belt lube and see if that goes the trick. With that, if they need replacing, what the labor like?

 

I used to have this problem i lubed up the belt

 

My noise mysteriously went away after a few days of driving. It started when I went out of town for a few weeks. Strange.

 

What do you lube it with? You cant use belt dressing, as it would possibly make it worse? Correct?

 

Didn't lube it with anything. Just magically went away.

 

I took a look at my serpentine belt and it looks to be in pretty good shape, even though the G has 93K on it. However, being that my G makes the same exact noise only at cold start up, whats the best resolution regarding? Taking my car to Infiniti equates to a **** ton of money spent on noise that hopefully doesnt seem too detrimental.....

 

Hey guys any ideas on this noise? With that, I'm really thinking its the starter in which its not the serpentine belts nor the tensioner

 

Its the starter for sure. Its the starter solenoid NOT dis-engaging after the start sequence is completed. Happened on a Honda and made similar noise.

If it was oil or a pulley, it most likely would be happening all of the time. Being the starter, it happens at startup.

Change the starter and problem disappears. GL with it.

 

That makes perfect sense! Thank you! With that, how difficult of a repair is it to replace the starter? Is it something that we can easily do?

 

I did it on a Maxima before. Easy to get to, hard to get 1 of the 3 bolts off. Got to it from the top. However with this VQ engine, it appears they put in on the lower part of the engine.

Here's the link to the FSM (Factory Service Manual). It tells you how to do it. If money is tight and/or you are mechanically inclined, I would give it a go on a Friday night, so that you can spend time on Saturday if you struggle. You can boil it down to having to remove 5 bolts and an electrical connector. Jacking up the engine is not a big deal. Its no harder than jacking up a car, except you only jack up the engine .5-1.5" to give yourself enough clearance to get the starter motor out.

You can do it if you are the curious type - remember 5 bolts and 1 electrical connector (if I counted it right).

http://www.nicoclub.com/FSM/G37/Coupe/2011/STR.pdf

 

Wow very helpful! Thanks!

 

If you manage to take this on, let us know how it goes and what you learned. Consider it "paying it forward"

 

Will do and thanks again for your help! I'm going to tackle it this weekend. Also, the noise was confirmed by Infiniti to be the starter. I just picked up my car yesterday from getting a new battery and my rear axles greased as well.

 

Started having the same issue with my G

The belt or pulley noise is extremely loud at cold starts and then eventually goes away when the car gets warmed up - I replaced my serpentine belt about 200 miles ago and the noise just started recently - I know for a fact it's not the belt. The noise seems to be coming from the water pump pulley

Super annoying!!! Strange that it's got quieter after getting a full tank of Gas - Not even sure how the 2 are related but just throwing it out there.. I might have damaged the tensioner pulley while replacing the belt but the noise started after 200-300 miles of belt replacement.

Any one knows what this is? Is this common?