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...

:icon17:

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?

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.

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 :rolleyes:

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 :o.

That sounds more like something is rattling or something metalic rubbing against something, not ticking.

My cousins g37 does it. My 08 altima 3.5 does it. My sister in laws maxima does it.
So I just think its most likely a VQ characteristic.

If it makes you feel any better, I have exactly the same sound coming from the under side of my Z. I'm going to have it checked at my next service along with my intermittent trunk not opening and condensation in the tail light.

Rudi.

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

heatshield from headers maybe? lol it's just a guess

Nothing to worry about its either the lifters ticking or the injectors and if you hear it after you have driven it and parked it is the exhaust cooling and contracting.

Wow that is weird, it could be anything, I would take it in to your dealer ASAP.

My opinion would be, it sounds like leaky exhaust system, because my old 280zx
made similar sounds, I had it check out & the muffler guy found a small hole in exhaust pipe after the cat. In you case it could be either defective seals or if you ran over something it may have puncture a small hole somewhere in the syst.
Let us know the updates,

Znism11

time bomb?
call the bomb squad!

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

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.