Lately, I have couple of issues with my 2003 G35 coupe. I just brought the car to an Infinity dealer for them to check it out (my car is still under extended warranty).
The first issue, when I apply the bake to stop at a stop sign or red light, it makes noise when I release the brake. It sound like the caliber release/ungrab the brake rotor. The noise seems like it come from the front brake and it is a little loud. I think there are problems with front brake calibers. The dealership checked the both front and rear brakes out and they said everything is fine.
The other issue is when I first accelerate the car and the engine is just a little warm (parked car overnight or a long period of time), I can hear the popping sound either from the exhaust or the engine. It sounds like a backfire problem, but I can’t tell if there is any fire comes out from the exhaust. The dealership will let the car sit overnight tonight, and will call me if they can find anything wrong tomorrow.
I want to know if anyone has these similar issues, or at least tell me the first issue that I have is normal for an old car. Thank you for any helpful advices.

free bump

One minute after he posts?

hey! whatever! Lol

*Infiniti

No one here has these similar issues? Does anyone notice brake release loud noise, or popping noise when accelerate the car with cool temperature engine?

Check the surface of your rotors, if you haven't gotten them replaced in a long time, they maybe warped or grooved which would cause for some noise when pressing or releasing the brake peddle. Also, check the brake pads, if they are worn, maybe cracked? then you could def have an issue with it grinding with the caliper.

If it were any other dealership other than Infiniti I'd have to say, "they checked the brakes" but we all know how reliable Infiniti is. Keep taking it back until they get it fixed right! Or have a independent brake/alignment shop check it out then you can return to Infiniti with the results.
Gary

Not sure about the "back firing" but the brake problem maybe a warped rotor or just needs to be resurfaced...

Thank you for your advices. The Infiniti dealership just called me said they could not duplicate the popping noise when accelerate the car with cool engine. I will come to the dealer tomorrow morning and try to duplicate the issue for them. For the brake issue, I noticed the rotor surface is not smooth all the way across when I run my finger over it. There are high points on each end of the surface, then low area in the middle (about one millimeter different, please refer to the image). Do you think this maybe the issue, and I need to replace the pads/rotors? I am getting the brake noise even when the wheels are not turning. Therefore, I thought it was the calibers, not the pads/rotors. Any ideas.

sorry that pic is too small to actually see anything

I am sorry for the small size image. I just updated the bigger size image.

High and low point might be normal at the edges due to the pads not contacting the whole area. Best thing to check for runout is dial indicator.