Clunk noise after startup, sporadically.

[deepimpact]

2021 AT: When I start the motor, there is a short clunk noise which is coming below, front of the car.

You can here it here, it's in German but the noise has no language .


It does happen sporadically. I could not really get a pattern when it is happening and when not. Did you ever experienced something similar? Or is there any explanation for that? It seems to be the drive shaft? Transmission?

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[Jaymar]

Could be the AGS system, does your car have those?

 

[sk47]

Hello; This is just a wild guess. Have you checked the engine mounts ( motor mounts)?

 

[deepimpact]

Could be the AGS system, does your car have those?

What's an AGS system? Everything is stock.

 

[deepimpact]

Hello; This is just a wild guess. Have you checked the engine mounts ( motor mounts)?

Hmm, I don't think so. It does happen very sporadically. Like 1 in 20 starts. Sometimes very loud, sometimes not so loud, and most of the time there is no noise. Just the noise of the start of the motor.

I will let it check by dealer start of next year.

 

[Jaymar]

What's an AGS system? Everything is stock.

AGS is the active grille shutter system, it closes shutters over the radiator at startup and under certain other conditions trying to maximize fuel economy. I don't know if the V6 had it but if you look through your grille to your radiator you'll see some black shutters if you have it. They snap close on startup sometimes and can make a noise like that.

 

[Soulja4187]

By any chance do you happen to have active exhaust?

 

[deepimpact]

I have the stock exhaust from 2021 AT GT.

I don't think it is coming from AGS. It's more a mechanical clunky noise which is coming below the car, from the front area. As far as I can remember it never happens on first start. When it happens, it happens when engine has run already for some time. Very weird. Maybe the dealer will find the reason.

 

[Soulja4187]

It’s your throttle body! There was a youtuber that had the same issue and it was replaced under warranty. You might have gotten a bad one.

 

[Soulja4187]

Here is a video

 

[deepimpact]

Here is a video

Wow.. Is very similar. U are right. Thx for the hint

 

[deepimpact]

Wow.. Is very similar. U are right. Thx for the hint

But why is it repeated on the video? Does he something special to provoke it? In my case this happens just in 5% of starts, when the engine is already warm.

 

[velocityblue5.0]

AGS is the active grille shutter system, it closes shutters over the radiator at startup and under certain other conditions trying to maximize fuel economy. I don't know if the V6 had it but if you look through your grille to your radiator you'll see some black shutters if you have it. They snap close on startup sometimes and can make a noise like that.

Wtf!? That’s a thing!? Wouldn’t you always want air flow though?

 

[Mike Pfeifer]

Wtf!? That’s a thing!? Wouldn’t you always want air flow though?

Depends. On a cold start, they can close to help get the temp up faster. If temp is not too high, can close to add mpg (this is more for CAFE stuff I think). Can open when needed otherwise. I think PP1 cars do not have them.

 

[Soulja4187]

Depends. On a cold start, they can close to help get the temp up faster. If temp is not too high, can close to add mpg (this is more for CAFE stuff I think). Can open when needed otherwise. I think PP1 cars do not have them.

As far I know only the ecoboost mustangs have the active shutter

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