Random knock with low RPM slow accellerating

[cgc9550]

Something I noticed here recently and somewhat random.
Car is a 2021 M1 6pd with an ESS G3 18K on the clock. Car runs completely normal and doesn't give any symptoms of a problem while driving....except....
When slowly accelerating, you get what sounds like a slight knock like someone was taping on the firewall with a pencil or something. Not super loud, only once around 13 - 1500 RPM or so but nothing else as you climb RPMs. It'll do it occasionally on the rev matching downshift, but primarily with the initial upshift with normal driving.

Heard it a couple of times a few weeks ago...went away, then noticed it late yesterday/this mooring.

Haven't had any time to get the hood popped a look around real good (quick glance only).

There anyone here who's had some think like this? Like I said...zero driving issues....just a little annoying knock.

Greatly appreciate any feedback.

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[accel]

maybe you should check this forum for a "bbq tick" term.

 

[ice445]

Do you have the ability to log? Could be the phasers rattling until oil pressure builds up.

 

[cgc9550]

Do you have the ability to log? Could be the phasers rattling until oil pressure builds up.

I do, but not going to even act like I know what the heck I'm looking at when I've datalogged for tuners in the past lol.

now, you may be dead on with what the issue is. But there isn't any rattle. It's literally a single knock. To give you an example of what it sounds like, I thought for a minute the UPR catch can was not secured and slowly rotating to hit the strut tower when accelerating (wasn't the case).

single knock with each gear shift (normal driving) at about 1300-1500 rpm.

 

[ice445]

I do, but not going to even act like I know what the heck I'm looking at when I've datalogged for tuners in the past lol.

now, you may be dead on with what the issue is. But there isn't any rattle. It's literally a single knock. To give you an example of what it sounds like, I thought for a minute the UPR catch can was not secured and slowly rotating to hit the strut tower when accelerating (wasn't the case).

single knock with each gear shift (normal driving) at about 1300-1500 rpm.

Hmm, that's an unusual one. Can't think of anything that wouldn't be worse at higher rpm too lol

 

[cgc9550]

Hmm, that's an unusual one. Can't think of anything that wouldn't be worse at higher rpm too lol

Yeah, it's weird as crap. I need to make time to get in there and get my wife or sone to slowly press the gas as I look around...but it seems to mostly do it under load (but not always smh)

I hate weird stuff like this.

 

[Snakebyte]

Single knock when changing at each gear would make me suspect a broken motor mount. I had that happen on my wife's T-bird years ago. (The engine would rotate up off the broken mount and contact the engine compartment structure.)

 

[cgc9550]

Single knock when changing at each gear would make me suspect a broken motor mount. I had that happen on my wife's T-bird years ago. (The engine would rotate up off the broken mount and contact the engine compartment structure.)

I thought that too, at first. But, it happens with slight acceleration, doesn't get louder/harder with hard acceleration. Something I can look at when I get in there but with what it's doing and what I've heard/felt with other broken motor mounts, not sure.
We'll see. I greatly appreciate the input.

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