Originally Posted by AK370Z

I have NO ticking noise from engine area. But, after driving more than half hour (meaning cats are fully warmed up), I get a little ticking noise. I am certain it's NOT engine or injector related. It's coming from cat or exhaust area. Camera was placed RIGHT under left cat, car idling.

VIDEO
YouTube - MOV01759

Originally Posted by wstar

Wow, I don't know wtf that is. Can you hear that just standing next to the car, without shoving a camera up by the cat?

The sounds I've been talking about are just subtle repetitive ticks, like a metronome synchronized click-track, that are completely stable (at a given rpm). What you've recorded is something very scratchy and erratic...

Originally Posted by AK370Z

It's the EXACT ticking sound you get when you park your car in the garage after driving for a while (engine off). But this one is audible with the engine on, right under the cats. if it helps, tomorrow I can take two videos at the same time with one camera under Left and one under right cat. Next time drive your car for a while. When you come home, instead of turning the car off, go outside and look under the cats. See if you hear anything and report back please. thanks.

To answer your question, YES you can hear it up to 2 feet away from car(if it's really quiet out) . Am I overreacting?

Originally Posted by wstar

Re: after the car is turned off, you're talking about the usual ticking from metal contracting as the car cools off? That video doesn't sound anything like that to me. But metal contracting/expanding and making that characteristic sound is normal even when the engine is running as the temps of the components change.

Originally Posted by Lyndo

the only thing i can think of is when you let the engine idle it starts to cool down the converter due to less exaust passing through(obviously lol) and then maybe the components inside and the heat sheild maybe contracting a bit, i don't get how this would make the sound on your video but thats the only explanation i could come up with, i did a search on google and wikipedia and other sites and read some stuff of catalytic converters (i'm kinda bored at the moment) but came up empty handed other than a thread on a cadillac forum of a guy describing the exact same thign as you and they seemed to think it was just the cooling off of the components as well but no one could say for sure so who knows.

edit: wstar beat me to it and said basically the same thing lol

Originally Posted by AK370Z

Thank you both. I think it makes sense. It's probably cats cooling down as there's less hot air passing through them. BTW, I just realized this thread is for ticking noise from the engine. Sorry OP if I cluttered this thread up .

Originally Posted by spearfish25

Those are normal sounds AK. My car does it as well. Don't worry about it.

Originally Posted by AK370Z

it's most likely exhaust/cat converter cooling and contracting.

Originally Posted by cave vulture

I get the exact same sound after the car has warmed up and it is clearly audible from inside the Z while driving if you listen for it.

Originally Posted by Lyndo

popcorn?