Short screeching sound right after the engine start

[murick]

I have one sound which I do not remember when it appeared, or if it was there from the beginning (though I do not think so as I remember starting the car the first time at the dealership and hearing only the pure rumble), which manifests right after the engine start, and takes approx. only 1 sec. then it does not reappear, at least for the periods I let the engine running on neutral. I believe I do not hear it in different vids on YT, so got some doubts.

It is clearly audible in the cabin, the best recording I got (which I included here) was from the spot under the windshield. When I tried to record it from the outside, my phone did not capture it. It sounds like something is priming up or resonating, cannot really tell if it comes from the engine/drivetrain or from some other device.
Anyone has any idea what it might be?

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[sakman84]

I have heard this exact noise before on GTs and on M1s at track attack in Charlotte. While I can't identify it, I definitely can say its a common noise, as long as you are oiled I wouldn't be worried. Does it happen even on starts after you are fully warmed up?

As with everything, If it bugs you, take it to Ford to alteast get it documented for warranty purposes.

BTW excellent sound clip.


I will listen for this on my own car especially during a cold start and report back.....

 

[murick]

Does it happen even on starts after you are fully warmed up?

Good question! I will need to check as I usually only drive somewhere and then stop . I can however confirm it is on each cold start (or several in a row, if I try few more).

 

[Esset]

maybe for better separation of the noise might be to start with silent mode? or better start with windows down, so you don't hear anything else

 

[CrackedHorn]

I can't hear much bc of the rumble but....screech on startup means bearing or belt 9/10 times. Sometimes, the throw-out bearing (manual trans) can make this noise with clutch pushed in as well.

Mine squealed a bit on startup and it progressively became worse. Never very loud though. Ended up being the water pump.

 

[murick]

I can't hear much bc of the rumble

Try with headphones if you can. This is very subtle in the recording, but clearly distinguishable, if you can hear it. In the car it is more pronounced but I guess my phone has limited recording skills .

Sometimes, the throw-out bearing (manual trans) can make this noise with clutch pushed in as well.

While it happens when starting the car (with the clutch pedal pushed), it is not tight to the clutch pedal. It starts a short while after the starter, and only takes around 1 sec, regardless how long one keeps the clutch disengaged. So it should not be throw-out bearing (if I understood correctly what throw-out bearing does).

For the belt I have no idea, but the water pump, or some other devices, which is priming itself, is something which crossed my mind (not the pump in particular, but some device as in "not the engine or the drivetrain").

 

[shogun32]

I couldn't make out the noise you were fingering (with headphones). Sounded perfectly normal. Try dry-cranking the engine for a few seconds and then do a real start.

 

[murick]

I couldn't make out the noise you were fingering (with headphones). Sounded perfectly normal. Try dry-cranking the engine for a few seconds and then do a real start.

How do you dry-crank the engine? And what would be the goal of this exercise? To check if it is an oil pump?

 

[shogun32]

How do you dry-crank the engine? And what would be the goal of this exercise? To check if it is an oil pump?

plant your gas pedal to the floor and hold the start button. The point would be to see if the sound comes back after said dry-crank, or if it's an artifact of say moisture on the belt that causes an initial slip when the sudden torque of turning over the engine is applied.

Is the belt tensioner also oil-driven in addition to static spring? Since in a cold start oil pressure has bled down at various points in the system, if the tensioner needs oil pressure "help" it may be that the belt is not quite tight enough on it's own to prevent minor slip and once oil pressure is up the tension is enough to stop the slipping.

 

[sakman84]

My car sat for a week, I did not hear this sound at start up. Though this isn't saying much as I have heard other Mustangs with that sound. Wish I could be of more help, if I ever hear it in mine I will report it.

 

[sakman84]

Thinking about this more, and I don't know why this would make a difference, but when I start my car, I push the button once with a quick press, this starts the electronics. I let the car do its boot up procedures, I do not attempt to start it until that process is done. Once all the beeps are done ect. I start the car by clutching in fully and long pressing the button.

This is the same for starting a car with a traditional rotating key assembly. Insert key, turn it to the "on" position, let the car boot up, after beeps and the dash warning lights extinguish, then turn the key to "start" to crank the engine. This is the proper way to start any car.

See if this makes a difference as opposed to an immediate long press of the start button. I doubt it will change anything.

 

[Cobra Jet]

The way you can tell if it's a belt issue is by this very simple trick:

Before starting the car, spray the belt down with Windex. Then start the car - if the squeal is gone, it's a belt issue.

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If it was a drive pulley bearing going bad, the sound would be persistent and won't go away with a Windex test.

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This is worse case - but on the 2003-2010 Explorer V6's - that squelch was normally heard upon start up when the harmonic balancer was failing... It was caused by the inner rubber elastomer slowly separating allowing the outer harmonic balancer pulley to slightly rotate (thus the brief squelch). Eventually the harmonic balancer would just separate, causing damage to the belt and anything else it deflected off of - if it didn't ruin the engine at speed too.

I'm NOT saying this is your issue, but when you start the car, at idle with the hood up, watch the harmonic balancer - make sure it has absolutely no wobble to it. If there is the slightest wobble, the inner elastomer is failing.

 

[Bulutt]

engine belt squealing?

 

[First Stang]

Sounds like a snake. Do you park near a bayou?

 

[murick]

Just a few comments (as I am not able to run the live tests at the moment).

when I start my car, I push the button once with a quick press, this starts the electronics. I let the car do its boot up procedures, I do not attempt to start it until that process is done. Once all the beeps are done ect. I start the car by clutching in fully and long pressing the button.

I do it the same way. The recording is from this type of start. I believe though it happens on a "cold" start as well.

Before starting the car, spray the belt down with Windex. Then start the car - if the squeal is gone, it's a belt issue.

Just to make sure I understand it right. Windex is for a windows cleaning, what is the purpose of spraying it on the rubber/metal? (I found a few references on the internet to use WD40, which I kind of understand.)

If it was a drive pulley bearing going bad, the sound would be persistent and won't go away with a Windex test.

Could you hear the recording? I would expect that if the pulley bearing was bad, the screeching will be heard all the time, no? The sound I experience is just a short burst with articulate beginning and end.

This is worse case - but on the 2003-2010 Explorer V6's - that squelch was normally heard upon start up when the harmonic balancer was failing... It was caused by the inner rubber elastomer slowly separating allowing the outer harmonic balancer pulley to slightly rotate (thus the brief squelch).

Are the harmonic balancer and the belt drive pulley the same thing? (I am new to both the Coyote details and the English nomenclature, was trying to find some reference, but still not clear on the subject. :()

Sounds like a snake.

Never thought about it this way, but you are right. There are no snakes in our parking lot though .

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