Noise after CX-5 is turned off..?

[nickswhip24]

Hearing a "whirring" noise for about a minute after turning car off-nothing seems to be running...happens all times-engine warm or cool
anyone else have this? Thanks!

 

[BoomerZoomr]

My Mazdas do that… the sound is very low. Fuel pump maybe… I don’t know.

 

[N7turbo]

Fuel pump. They all do it, even my Pontiacs from 20 years ago did it.

 

[nickswhip24]

fuel pump....huh...ok...strange...so it needs to be ready for the next cycle or something-sorry ...first car with a high pressure fuel system....i saw some videos online and most were headlight issue's...i would love to repost the small video i saw on this site....at the very end of it...you get a 2 second soundbite of what i hear-guess i could do my own little video as well

 

[N7turbo]

Yes, the headlight is also a possibility and is known issue. I've so far been lucky that my 2023 doesn't have it (knock on wood), even as I see several other 2023's failing. Make sure it's not coming from a headlight and if it is, take it in for a warranty replacement asap.

 

[cz5gt]

Fuel pump. They all do it, even my Pontiacs from 20 years ago did it.

its not the fuel pump.
Its the throttle body as far as I know. Hear a final "flap/click" sound after 40-50sec and the noise is gone.

Yea the Headlight issue/noise is a warranty item. Separate type of noise.

 

[N7turbo]

Its the throttle body as far as I know. Hear a final "flap/click" sound after 40-50sec and the noise is gone.

We're talking about the whine, I thought?

 

[cz5gt]

I was referring to the whirring/buzzin noise from the engine compartment upon engine shutdown. For about 1 minute, then a click/flap closing and no more buzzing. My Turbo CX5 does that.

 

[RL911]

It’s the fan to cool the headlights.

 

[N7turbo]

Even our V6 Turbo Diesel Mercedes has the fuel pump sound.

This is really easy to hear if you're in a garage.

 

[cz5gt]

Which fuel pump are you talking about?
Only the one in the fuel tank is electric. The buzzing noise is in the engine compartment.

 

[nickswhip24]

its not the fuel pump.
Its the throttle body as far as I know. Hear a final "flap/click" sound after 40-50sec and the noise is gone.

Yea the Headlight issue/noise is a warranty item. Separate type of noise.

i think you are correct-i am putting my cupped hands over hpfp and pitch changes,then in series i hear 1 click,then 1 click near throttle body then 1 more click from relay box and its gone-just strange because i am around a few other cx-5's and i dont hear it-last nite i heard sounds like the pump was still running-grabbed a little screwdriver to put on top of solenoid but i guess the voltage was to low to feel the magnetism,if i really want to get nuts i could get tools to check fuel rail pressure or back probe the solenoid-still under warranty so this is why i am on the hunt,thanks
of course my ocd is strong on this so i will keep learning and get back if i get the answer

 

[RattleCanAR]

It's not the fuel pump. My CX50 H and my CX5 NA both make the noise. I think it's headlight fans. I don't see why it's a warranty issue, it's normal and they all do it for 5 seconds or so after you turn off the car.

 

[N7turbo]

And they run even if you don't use the headlights?

 

[nickswhip24]

It's not the fuel pump. My CX50 H and my CX5 NA both make the noise. I think it's headlight fans. I don't see why it's a warranty issue, it's normal and they all do it for 5 seconds or so after you turn off the car.

ok,i need to do a deepdive-headlites with fans? thats crazy....do they really cost 2k each?

 

[Mazdiod2]

Mine does this noise for a bit every time I turn off the ignition, even if I hadn't started the engine.

 

[SimpleCanuck]

ok,i need to do a deepdive-headlites with fans? thats crazy....do they really cost 2k each?

Yes, the headlight assemblies do cost upwards of that amount. I had to have both headlight assemblies replaced on my '22 due to excessive rattling and buzzing (there is a TSB for this).

The left one was replaced a year and a half ago while it was still under the base 3 year warranty. The right one was replaced 2 months ago, but my warranty had already expired. That one cost $1800 CDN, and that is mostly the part (labour is less than an hour).

With that said, it is normal for the headlights to give a very low hum when they are on. However, in this case, the sound you originally described is not from the headlights because my car has always made this sound even after the headlight assemblies were replaced. It originates from somewhere in the engine area.

 

[zx10guy]

As stated, yes, headlight assemblies can cost $2k or more depending on the manufacturer. My 2013 BMW 135i had to have both headlight assemblies replaced when I hit a deer. If I recall correctly, the headlight assemblies were about $2500 each. The headlight assemblies have a ballast for the HID bulb and electronics/motors for the adaptive headlight system. This was a few years ago. Who knows how much they're going for now.

As to fan noise or similar with the factory LED headlights, I don't know. I haven't heard anything but I haven't been focused on looking for the noise either. When I had my 2019 C-HR, I replaced the halogen blubs with some drop in LED units. The LED assemblies had a fan on the back which was used to keep the LED emitters cool. The fans being on was very noticeable. I also had prior an HID retrofit kit that didn't have a fan. Nor does the HID system in my BMW.

 

[N7turbo]

I build PCs and have worked with electronics most of my life.

I don't hear anything that sounds like fans. Just an electronic/pump kind of noise.