my car make pretty big noise when i first turn my engine on it is still there for while..... anybody having same problem?????

 

search is your friend

 

You talking about a metallic rattling sound?

 

I am on my second exhaust trying to get rid of this sound. It is not back yet, but when the car is cold, it does still make a lot of noise. Still don't know if I am happy with it. This is the fourth problem that it has had to go back to the dealer for.

With the first exhaust it seemed to resonate at the "fast idle" speed of 1200 ish RPMs and never stopped even after it warmed up.

 

Its just needs to warm up, the muffler needs to warm up. give it 30secs it goes away quick.

 

This is something that occurs during cold starts. My previous generation G35 did the same thing just to a slightly lesser degree.

 

Yeah my dealership told me its normal, **** i dont care it goes away quick anyway

 

You wouldn't have been able to stand my first exhaust. It sounded like there was a beer can in there rattling.

 

mine does not go away even when warm..

 

That's been my experience as well even on very cold days.

 

If the rattle doesn't go away, you need a muffler replacement. They replaced cats back on mine. Now it sounds reasonable, and the "cold muffler" sound goes away after just a few seconds.

 

mine typically last about 15 seconds or so just when the car is idling high on a cold start. Seems to go away after that

 

i have the same at bout 2700 to 3000 rpms for maybe the first few gears after ignition, then it goes away.

 

my G sedan does that as well when i start up on cold pipes

 

haha, see you wouldnt have this problem if you had a 2008 BMW 528i!!! hehe
jk(not rlly) but my g35 had this problem i HATED it.