Acceleration Buzzing Sound (CT4-V Blackwing)

[ngoni]

Yeah definitely something metallic is loose. If it was a BMW, I'd say you had a loud variable valve (VANOS) system which for many cars is pretty normal. But definitely not normal for a 4BW.

 

[Seth]

it almost seems like something internal (engine, transmission) to me. It seems directly related to RPM speed and particularly happens under load.

Things we’ve tried and ruled out are ANC (active noise cancelling) interference, and fuel pump / fuel lines.

Thank you guys for confirming I’m not crazy though. I think it’s getting louder over time, which is annoying but almost a good thing because it becomes harder for the dealership to ignore.

 

[NewCaddy]

@Seth Is sound evident, regardless of what drive/traction mode you are in?

 

[Seth]

@Seth Is sound evident, regardless of what drive/traction mode you are in?

Yep, it’s the same in tour and V and all different traction modes. I have an appointment at a different dealership this Thursday.

 

[jonny_77]

Not normal. It was the first thing I noticed on my 2022 CT4-V Blackwing 6MT. I purchased the vehicle with 1900ish original miles on 5/27/25. I hear the buzzing in all gears but is especially prominent in 3rd and 4th at highway speed. I can attenuate the noise by grabbing (hard) the shifter. I had the dealership service manager do some non-invasive troubleshooting before a long cross-country trip. He heard the noise and ran acoustic tests with his team. They reached a stopping point and think the best thing to do is escalate it to a Cadillac field engineer. I have another appointment with a Cadillac dealer out west to look into this and I am appreciative of this forum to work a solution. I will attempt to post my video with sound shortly.

 

[jonny_77]

 

[DCV]

I'd take apart the whole center console check for loose things then put back together. The shifter too. Since once you dampen it with your hand, it goes away....must be something loose in there...a clip or washer or something. Dealers generally don't want to do things like that, cause it's not in the repair book the service writer looks at.

 

[jonny_77]

Not normal. It was the first thing I noticed on my 2022 CT4-V Blackwing 6MT. I purchased the vehicle with 1900ish original miles on 5/27/25. I hear the buzzing in all gears but is especially prominent in 3rd and 4th at highway speed. I can attenuate the noise by grabbing (hard) the shifter. I had the dealership service manager do some non-invasive troubleshooting before a long cross-country trip. He heard the noise and ran acoustic tests with his team. They reached a stopping point and think the best thing to do is escalate it to a Cadillac field engineer. I have another appointment with a Cadillac dealer out west to look into this and I am appreciative of this forum to work a solution. I will attempt to post my video with sound shortly.

@Seth

 

[jonny_77]

The prognosis given back by the Cadillac service shop is a defective throw out bearing. The repair is scheduled for late September. I will keep the forum posted.

 

[DCV]

Given that when you press down the noise goes away, I'm not sure why they think it's a throwout bearing, as I don't see how pressing on the shifter can in any way, affect the throwout bearing. They are not connected in any way.

 

[jonny_77]

The Cadillac service center in Hamilton, MT had my Blackwing from Tuesday morning through Friday morning and returned my vehicle with a replaced throw out bearing after confirmation that the original had failed. The bearing and all of the work on the transmission to get to it was performed under warranty (no cost). There is no longer a buzzing sound after 100 mi of driving. I'll check in periodically but am heartened by the fact that the sound is gone.

 

[jonny_77]

Given that when you press down the noise goes away, I'm not sure why they think it's a throwout bearing, as I don't see how pressing on the shifter can in any way, affect the throwout bearing. They are not connected in any way.

I'm not an expert but that is the diagnosis provided and the fix (at least for the first 100 mi) seems to have remedied the issue.

 

[jonny_77]

Yep, it’s the same in tour and V and all different traction modes. I have an appointment at a different dealership this Thursday.

See update below.