RMB5190

iTrader: (2)

If it's a popping sound when the car is turned off BB answered the question at the beginning of the thread. If its a ticking / tapping sound coming from under the car it's most likely the cats. The honeycomb frame inside falls apart and that's what's rattling around. Will be replace by dealership under warranty pending ca's age and mileage

Source: Just had it done.

aj0415

It only happens after driving and then im sitting still idling with the car on. Basically sounds like when you shut it off and its cooling down but while its on and idling. As soon as i give it a little gas above 900 RPM's or so it goes away and then back as soon as im back to idle. Just got under car and checked it out today. Definitely coming from the ypipe on both sides. Think it may be the heatshield on the ypipe. Gonna try tightening the claps and see if that helps. Heard some people have had success with that.

filipinoy

iTrader: (2)

I've had this ticking sound coming from underneath my car for years now. I only notice it when im in the drive thru since I turn off the radio. Doesn't seem like there is anything wrong with the car

aj0415

Yep mine is the same way. Hear it in the drive thru every time. Its been like that since i got it 2 years ago and i've just left it alone. No engine lights or anything but I want to fix it if it really is just tightening the heat shield.

Kris9884

iTrader: (3)

Guys... This is COMPLETELY normal.. It's the most basic form of science. The exhaust is cooling and shrinking.

aj0415

This is NOT normal when a car is at full temp and the engine is ON and IDLING. It is normal when the car is OFF. There should not be that much cooling while idling to cause it to make this sound.

lostOne

iTrader: (2)

I too have this issue... This is like the 5th car I've owned and the g37 is by far the loudest haha

RMB5190

iTrader: (2)

I think those experiencing the noise are car savvy enough to know what normal metal popping sounds like as it cools.

More than likely, it's one of three things:

VVEL tick (completely normal with these cars). Sometimes using ester oil alleviates this.

Heat shield is loose and knocking around

Cats are crumbling from the inside which is the rattling / popping sound

Kris9884

iTrader: (3)

Oh, your car is still running while ticking?.. I didn't see that part, my bad

lostOne

iTrader: (2)

Yeah I hear it when I am in a drive thru .. I have yet to get under the car and see whats making the noise

Kris9884

iTrader: (3)

Well, if you're certain its not the exhaust ticking, maybe try and mount a go pro underneath? Or, let the car run while on jack stands and turn it off and immediately track it down underneath?

PNW_IPL

iTrader: (5)

If it aint broke dont fix it. Turn the radio up or buy an exhaust