Noise after shutting car off

[blizz81]

Forgive me for not searching before posting this, as there's probably threads out there addressing the issue already...but I wanted to ask if anyone had noticed their 3 making noises after shutting the car off. I've noticed this a few times, most recently last night after my car had been off for a couple of minutes. The noise sounds like an electric...well, "squeal" wouldn't be the word, but I can't really describe it any better. It was definitely not an exhaust-related noise, and was definitely coming from somewhere down in the engine bay, tranny side if I had to guess (alternator?)

I think I noticed a similar noise on my last car, and had it rationally explained to me once before, but I was kind of curious since I noticed it happen at least two minutes since the car had been running. I'm not worried - I'm just curious as to an explanation. Any thoughts?

 

[goldwing2000]

Fuel vapor pressure building up/bleeding off? Power steering pressure bleeding back to the reservoir? It's really a tough call without actually hearing the noise.

 

[wongpres]

It's a fan to help cool off the car - I've heard it many times and I know the RX-8 has it as well.

Also moved to engine & performance.

 

[mobomelter]

theres something beyond the fan that "clicks" off or something shortly after the car is off. because i've popped the hood right after i've shut the car off, heard it, and noticed the fans weren't running.

 

[uclap5]

time bomb.

 

[Shane5425]

maybe a relay shuting off??

 

[KpaBap]

is this with the key in the ignition or out?

 

[jer3]

Ya, my car does this randomly after it's been shut off. It's normal, I'm not sure where it's coming from either, but it sounds more like pressure being let off from something. I think it may be related to the AC/defrost.

 

[tgv121281]

This may be a shotr in the dark, but I've noticied the noise too...for me it happens about 20seconds after shutting the car off(key out)...and I've heard it w/ the hood open standing in front of it....I dont claim to know anything about engines, BUT I was thinking it may be the electric throttle resetting itself??? Or something to that effect. It sounds like its coming right from the throttle body, and w/ my limited knowledge thats all I can come up with....If anyone wants to completely blow this theory out of the water, please do...at least I'll learn something??

 

[blizz81]

I've heard a lot of fans (and used to own an Acura, so know all about radiator fans operating after the car has been shut off) and that doesn't sound like a fan at all, but I should probably check and see if I can open the hood quickly the next time I notice it.

This is with the key out of the ignition.

It doesn't really sound like something releasing pressure - more electric than a 'pssssshhhhhh'.


I think time bomb is the best explanation as of yet.

 

[solid_snake]

All cars do that. That clicking noise are the valves opening and closing. This does not indicate abnormality. Hope this helps

 

[curacer1]

YOU KNOW I HAVE ALWAYS SUSPECTED THE TIME BOMB, I COULD SEE THEM PUTTING A BOMB THAT WAS SET TO GO OFF ONE DAY OR 1 MILE AFTER THE WARRENTY EXPIRED. THEN BOOOOOM (upyours)

 

[mobomelter]

ha ha. all the more reason to turbo it when the 100k engine explodes.

 

[Brian MP5T]

Flux- Capasitor

 

[Shane5425]

Flux- Capasitor

yeah, its powering down from 5 gigawatts, so it will make noises..

 

[Mazda3ofKent]

YOU KNOW I HAVE ALWAYS SUSPECTED THE TIME BOMB, I COULD SEE THEM PUTTING A BOMB THAT WAS SET TO GO OFF ONE DAY OR 1 MILE AFTER THE WARRENTY EXPIRED. THEN BOOOOOM (upyours)

that would explain the ticking nosie and the red light

 

[Geeshik]

I heard that noise tonight as well on our '07 Mazda5. It sounded like it was coming from near the air box, by the MAF sensor maybe? Do your cars have the switch on the wheel to always have the cruise control on, so you just need to push the 'set' button? I wonder if turning ours off would make the noise stop. We leave ours on almost all the time, it is a little strange to see the light on the dash though when you are driving around. When we first bought it, I thought there was something wrong with the car, like a check engine light.