hey guys, i have a popping sound coming from under the car when it is idling/off, just wondering what it is. i assume that this might be the exhaust cooling off and the metal contracting?

 

I get the same noise, and your assumption is correct.

 

im pretty sure if u replace the cats... the sound will go away.

 

Pretty sure it's the Cat

 

thanks alot!

 

oh and a little off topic, does anyoune here by chance attend la costa canyon high school? Because i'v seen 3 sc400 in the parking lot.

 

i get the same noise

 

Are you sure? My car does the same thing, and it has only 50k miles on it.
I shouldn't have to replace my Cats yet?

 

The sounds are normal. Don't replace anything unless they are excessive. Every Lexus/Toyota we've owned does this. Our 2006 Avalon has 4k on the clock and it does it too after a hard drive.

 

There are a lot of threads on this, it's 100% normal, all of our cars do it no need to worry, it's not your cats going bad.

 

Im just gonna restate the obvious. When something heats up it expands, such as metal, but then when it cools back down, it contracts to its original form. Thereby causing you to hear the crackling sound.

 

Every vehicle I have owned did this- its all natural

 

hha, ive never even thought twice about that ticking/poping sound you hear when the car is off.. i guess its from hearing it from a young age it was there and kinda just ablivious to it.. haha cool, i learned something new today