Buzzing sound coming from under hood after turning off car? Please help me out.

B

BB33

Member
Hello all,

I am new to the site, and have a question. I recently purchased a 2014 Mazda CX5 and I noticed something today I wanted to run by you all to see if it is normal. I was driving today like normal and came home and parked my car in my garage, my garage was shut and after I turned the engine off by pressing engine start stop button I got out of the car and I heard this buzzing sound that lasted maybe 30 seconds and then sounded like something shut off, sounded like sommething under the hood. Is that normal? I have never heard it before because usually my garage is open when I get out of the vehicle or I am outside and you can hear all the background noise such as other cars so I could not hear it before. Is that normal operation for the vehicle? Maybe it supposed to make that sound when you shut it off I just didnt notice it. If someone could please help me out here that would be great. Thank you. sounds like a buzzing sound under the engine area but it shut off after about 30 seconds. I was in the garage with the door closed so maybe it echos differently because usually I am outside. Thanks.
 
Yes, normal. Haven't seen a post yet that tells us reason for sure.
 
Yes, normal. It's the fan on intercooler running. Every car I've owned did this.
 
As I said before, its a sound of motor attached to the EPS. When you turned of your engine, the electrical motor will shut off and lock the steering. It will produce some kind of buzzing sound and its normal.
 
Thank you everyone I appreciate the fast responses. the buzzing sound I here isnt the fuel pump is it? It seems like its electrical. Anyone else have a cx 5 that has done this and how did you notice it?
 
BB33 said:
Thank you everyone I appreciate the fast responses. the buzzing sound I here isnt the fuel pump is it? It seems like its electrical. Anyone else have a cx 5 that has done this and how did you notice it?
Click to expand...

Mine does it all the time. I notice it because I can hear and feel. It's one of the few mechanical/electronic features of the car I don't have any complaints about.
 
Same Here

BB33 said:
Thank you everyone I appreciate the fast responses. the buzzing sound I here isnt the fuel pump is it? It seems like its electrical. Anyone else have a cx 5 that has done this and how did you notice it?
Click to expand...

My 2.5L CX-5 (build July 2013) makes the same sound for about 20 seconds after the igntion is switched off - even if the engine isn't started. There's no intercooler so it isn' that. No fans running either. Doesn't sound like a motor - more like a relay buzzing. Noticed it from day 1 but still can't figure it out.
 
I think the sound this thread is referring to is the variable valve timing motor:
The following is copied from the service manual (see how-to section to get the manual):

The PCM divides the electric variable valve timing motor drive range modes according to the engine operation conditions, and determines the output duty ratio to the electric variable valve timing actuator in each mode.
Mode name

Control description

Control conditions


Feedback mode

Continuously monitors the intake valve timing if it matches the target intake valve timing determined according to the engine operation condition, and controls the output duty ratio based on the result.
Except for energization cut mode and phase holding mode



Energization cut mode
If there is any malfunction in the electric variable valve timing driver, the intake valve timing is held at the maximum retard position to stabilize the engine speed.
Electric variable valve timing driver malfunction



Phase holding mode
To improve the startability, the phase of the electric variable valve timing actuator is held at the intermediate position after the engine is stopped.
Applied VIN (assumed): JM3 KE2*E*D# 100001−148106
After the engine is stopped (within a specified time)
Applied VIN (assumed): JM3 KE2*E*D# 148107−
After the engine is stopped (Depending on the engine coolant temperature, operates after a certain period has elapsed from when the engine was stopped to suppress heating of the electrical variable valve timing motor.)
 
piotrek91 said:
I think the sound this thread is referring to is the variable valve timing motor:
The following is copied from the service manual (see how-to section to get the manual):

The PCM divides the electric variable valve timing motor drive range modes according to the engine operation conditions, and determines the output duty ratio to the electric variable valve timing actuator in each mode.
Mode name

Control description

Control conditions


Feedback mode

Continuously monitors the intake valve timing if it matches the target intake valve timing determined according to the engine operation condition, and controls the output duty ratio based on the result.
Except for energization cut mode and phase holding mode



Energization cut mode
If there is any malfunction in the electric variable valve timing driver, the intake valve timing is held at the maximum retard position to stabilize the engine speed.
Electric variable valve timing driver malfunction



Phase holding mode
To improve the startability, the phase of the electric variable valve timing actuator is held at the intermediate position after the engine is stopped.
Applied VIN (assumed): JM3 KE2*E*D# 100001−148106
After the engine is stopped (within a specified time)
Applied VIN (assumed): JM3 KE2*E*D# 148107−
After the engine is stopped (Depending on the engine coolant temperature, operates after a certain period has elapsed from when the engine was stopped to suppress heating of the electrical variable valve timing motor.)
Click to expand...

That could be it. The sound seems to be front and centre - not sure if that is where the valve timing actuator is located. It makes sense that the VVT needs to be positioned after the engine is stopped but it seems to take a long time (20-30 seconds). Also, without starting the engine, cycling the ignition on/off starts the sound over again. Weird.
 
Hi.
I know this is a old thread but i am having a similar noise with my wifes Mazda 5 Sport,
except the car develops the noise whilst driving. It sounds like a motor has clicked in the after
a couple of seconds you hear a click as it stops. I am assuming the click is from a relay?
the noise seems to be coming from under the hood infront of the drivers position.
 
If the car is under warranty I'd take it back to the dealer and have them replicate the issue and figure out what it is. I can't think of anything that would create such a noise while driving aside from a faulty AC compressor a very loud radiator fan. If you have auto climate control, possibly that could be the culprit?
 
arioch said:
Hi.
I know this is a old thread but i am having a similar noise with my wifes Mazda 5 Sport,
except the car develops the noise whilst driving. It sounds like a motor has clicked in the after
a couple of seconds you hear a click as it stops. I am assuming the click is from a relay?
the noise seems to be coming from under the hood infront of the drivers position.
Click to expand...

5 or CX-5? Different vehicles.
 
Hi Craigo, it's the 5.
I have found the 5 section and posyed in there so please ignore me.
I only reopened the thread as it sounds like a similar problem that my wifes car is having.
 
jeisensc said:
Yes, normal. It's the fan on intercooler running. Every car I've owned did this.
Click to expand...

what on earth are you talking about?

the CX-5 is an NA motor. it doesnt have an intercooler.

this buzzing sound can be audible if you've been driving the car aggressively and then park. it is the radiator fan extracting heat out of the coolant. if you open the engine bay and it's not that, then it's some sort of other electrical component. it's perfectly normal.
 
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