CT5-V 5BW humming/whirring noise - engine related

[FISH22]

Hey everyone; first off, the last week in my '23 5BW has been incredible. Aboslutely cannot get enough of this car, and every commute is a blast. Coming from a '21 BMW M3, a lot of the 5BW stuff is a nice change: engine, manual, size/comfort. Glad to be here. To provide some context, this is my first GM product.. I've been spoiled by German build quality for quite some time now. I have come across a few things on the 5BW that are subpar - but that's ok, I bought this car for other reasons.

I know these "noise" threads can get confusing or become pointless. Since new/about 10'ish miles, I've picked up on a sound from the front of the car. Heard from inside the cabin. Seems to coincide with RPM. The sound can be best described as a humming, almost soft buzzing, like a computer fan or fuel pump... if that makes sense. At idle, sitting, no sound. With slight revving or pulling away from a stop, the sound will come online. I'm positive it is not tire noise, and it stays a constant frequency (does not get louder as speed or RPM increases). Takes a few miles, warming up, for it to be noticed.

I guess I'm more curious on what pumps might be utilized for the LT4; is there any sort of intercooler pump or possibly differential pump (I understand that it is cooled?). Anyways, shot in the dark here. Car is at 400 miles now, sound hasn't gotten worse, but I notice it. Thanks for any feedback!

 

[Sphinx]

Power steering whine? Try turning the wheel while stationary and see if you hear anything.

 

[668LT4]

Welcome here! I will look forward to your inputs on the Cadillac. I wish I could be more helpful to your specific question about the noise and various pumps. We have some good gearheads here who might have some insight.

I owned a 2022 M4 Competition xDrive for about 2000 miles before my CT5-V Blackwing arrived. I loved the looks, inside and out. Loved the paint, the carbon fiber, all the high end materials. The interior was so cool, but honestly I found myself playing with the infotainment all the time. In my Blackwing, I hardly ever do. It is so much more about "driving".

In my honest opinion, the drive experience of the Cadillac is so much more visceral and engaging than the M4. The M4 would crush it to 60, no doubt there, if you care about that. But the car is otherwise bland to drive. Vague on the front end. The engine sound is not appealing to me, and with that ridiculous BMW enhanced sound feature, downright deplorable (literally that was my biggest complaint about the car).

I could not be happier to have dumped mine and not lose too much on a basically brand new car. I hope and expect you will find your Blackwing as enjoyable as I do mine.

 

[shbox]

Power steering whine? Try turning the wheel while stationary and see if you hear anything.

With electric power steering?

 

[Sphinx]

With electric power steering?

Good point. No idea how an electric PS system works.

 

[TheShark]

Hey everyone; first off, the last week in my '23 5BW has been incredible. Aboslutely cannot get enough of this car, and every commute is a blast. Coming from a '21 BMW M3, a lot of the 5BW stuff is a nice change: engine, manual, size/comfort. Glad to be here. To provide some context, this is my first GM product.. I've been spoiled by German build quality for quite some time now. I have come across a few things on the 5BW that are subpar - but that's ok, I bought this car for other reasons.

I know these "noise" threads can get confusing or become pointless. Since new/about 10'ish miles, I've picked up on a sound from the front of the car. Heard from inside the cabin. Seems to coincide with RPM. The sound can be best described as a humming, almost soft buzzing, like a computer fan or fuel pump... if that makes sense. At idle, sitting, no sound. With slight revving or pulling away from a stop, the sound will come online. I'm positive it is not tire noise, and it stays a constant frequency (does not get louder as speed or RPM increases). Takes a few miles, warming up, for it to be noticed.

I guess I'm more curious on what pumps might be utilized for the LT4; is there any sort of intercooler pump or possibly differential pump (I understand that it is cooled?). Anyways, shot in the dark here. Car is at 400 miles now, sound hasn't gotten worse, but I notice it. Thanks for any feedback!

5BW 6M, 6,000 miles here. We are experiencing something similar during highway cruising. Our description is a constant thrumming sound with the exhaust in it's quietest setting. At 80+ it really ramps up.... to the point where the wife is like I cannot road trip in this thing. And after an hour of it, I agree. Here is the interesting part - it is interior height based. On throttle, constant speed, say 60-70.... if you lower your head towards the steering wheel, your brain is immediately hit with a humming/thrumming sound that reverberates like a bad headache at a horrible pitch/frequency. As speeds approach 80+, you can literally feel/hear the noise raising towards the car ceiling and into your head. I doesn't sound like tire noise. Maybe a stuck exhaust valve?

 

[FISH22]

Welcome here! I will look forward to your inputs on the Cadillac. I wish I could be more helpful to your specific question about the noise and various pumps. We have some good gearheads here who might have some insight.

I owned a 2022 M4 Competition xDrive for about 2000 miles before my CT5-V Blackwing arrived. I loved the looks, inside and out. Loved the paint, the carbon fiber, all the high end materials. The interior was so cool, but honestly I found myself playing with the infotainment all the time. In my Blackwing, I hardly ever do. It is so much more about "driving".

In my honest opinion, the drive experience of the Cadillac is so much more visceral and engaging than the M4. The M4 would crush it to 60, no doubt there, if you care about that. But the car is otherwise bland to drive. Vague on the front end. The engine sound is not appealing to me, and with that ridiculous BMW enhanced sound feature, downright deplorable (literally that was my biggest complaint about the car).

I could not be happier to have dumped mine and not lose too much on a basically brand new car. I hope and expect you will find your Blackwing as enjoyable as I do mine.

Thanks for the welcome! And you hit the nail on the head; the 5BW is a MUCH better drivers car. After 2 years with the M3, which I truly loved, it seemed to be missing something. It was just too sanitized, and dare I say "boring"? Years ago, I had a manual E90 M3 (4.0L N/A V8), and the 5BW is very reminiscent of that vehicle. Never really thought I'd be saying this, but after 20+ years of different sports car, the 5BW is easily my favorite vehicle. The satisfaction and fun it provides is just unmatched in this price point.

5BW 6M, 6,000 miles here. We are experiencing something similar during highway cruising. Our description is a constant thrumming sound with the exhaust in it's quietest setting. At 80+ it really ramps up.... to the point where the wife is like I cannot road trip in this thing. And after an hour of it, I agree. Here is the interesting part - it is interior height based. On throttle, constant speed, say 60-70.... if you lower your head towards the steering wheel, your brain is immediately hit with a humming/thrumming sound that reverberates like a bad headache at a horrible pitch/frequency. As speeds approach 80+, you can literally feel/hear the noise raising towards the car ceiling and into your head. I doesn't sound like tire noise. Maybe a stuck exhaust valve?

Thanks for the feedback! While yours seems a bit different from mine, it does sound like an NVH issue like mine. I usually won't bring the car into the dealer for something like this, as it usually ends up being a "sorry, we couldn't reproduce the noise". I'll likely just live with it until it either gets worse, or I just get over it.

 

[rdollie]

I too find modern BMWs lacking in engagement (we have a twin-turbo V8 X5 and missing engagement on that one isn't a big deal.) Still have an e90 M3 but the CT5-V BW is definitely my favorite modern sedan for driving experience.

 

[dbonebre]

I picked up a '23 6MT 5BW two weeks ago and I have a similar issue. I believe it is from the speakers as there was a loud crack from the right front passenger speaker (I thought the sound was coming from the right front passenger wheel the first few times it occurred) and it went away. It does not occur at idle or if revving the engine at idle, just when in motion. It returns after a harder acceleration but does not begin until then. When the speaker made the cracking sound and it went away it makes me lean towards the artificial noise and noise cancellation theory. The dealership had no feedback from the video I sent which is attached.

 

[dbonebre]

I picked up a '23 6MT 5BW two weeks ago and I have a similar issue. I believe it is from the speakers as there was a loud crack from the right front passenger speaker (I thought the sound was coming from the right front passenger wheel the first few times it occurred) and it went away. It does not occur at idle or if revving the engine at idle, just when in motion. It returns after a harder acceleration but does not begin until then. When the speaker made the cracking sound and it went away it makes me lean towards the artificial noise and noise cancellation theory. The dealership had no feedback from the video I sent which is attached.

 

[Head Hunter]

I picked up a '23 6MT 5BW two weeks ago and I have a similar issue. I believe it is from the speakers as there was a loud crack from the right front passenger speaker (I thought the sound was coming from the right front passenger wheel the first few times it occurred) and it went away. It does not occur at idle or if revving the engine at idle, just when in motion. It returns after a harder acceleration but does not begin until then. When the speaker made the cracking sound and it went away it makes me lean towards the artificial noise and noise cancellation theory. The dealership had no feedback from the video I sent which is attached.

Easy way to test would be pull the 40A F26(?) fuse in the rear fuse box for the audio system. If it goes away then it’s related to the ANC or engine audio-feed.

 

[BlueBird]

Hey everyone; first off, the last week in my '23 5BW has been incredible. Aboslutely cannot get enough of this car, and every commute is a blast. Coming from a '21 BMW M3, a lot of the 5BW stuff is a nice change: engine, manual, size/comfort. Glad to be here. To provide some context, this is my first GM product.. I've been spoiled by German build quality for quite some time now. I have come across a few things on the 5BW that are subpar - but that's ok, I bought this car for other reasons.

I know these "noise" threads can get confusing or become pointless. Since new/about 10'ish miles, I've picked up on a sound from the front of the car. Heard from inside the cabin. Seems to coincide with RPM. The sound can be best described as a humming, almost soft buzzing, like a computer fan or fuel pump... if that makes sense. At idle, sitting, no sound. With slight revving or pulling away from a stop, the sound will come online. I'm positive it is not tire noise, and it stays a constant frequency (does not get louder as speed or RPM increases). Takes a few miles, warming up, for it to be noticed.

I guess I'm more curious on what pumps might be utilized for the LT4; is there any sort of intercooler pump or possibly differential pump (I understand that it is cooled?). Anyways, shot in the dark here. Car is at 400 miles now, sound hasn't gotten worse, but I notice it. Thanks for any feedback!

Yesterday was the first time I heard this. It sounds like an electric "hum" that changes with acceleration. It was hot out and I had the A/C cranked up and no radio on. Maybe it is engine fan noise related? I pick up on this kind of stuff and wish I didn't Never heard it before until now, so it seems like something that suddenly happens? I had the exhaust in track mode all day. The sound, while probably not noticeable to anyone else, was really irking me.

 

[FLYARMY]

GM Engineers state that the fix for that "noise" .....is to crank some cool driving music. Joe Satriani highly recommended !

On a serious note.....I've heard guys say that the radiator fans can be a bit loud when the temps are hot. Could it be that ?

 

[BlueBird]

GM Engineers state that the fix for that "noise" .....is to crank some cool driving music. Joe Satriani highly recommended !

On a serious note.....I've heard guys say that the radiator fans can be a bit loud when the temps are hot. Could it be that ?

That was my guess, but does fan speed and vehicle speed affect one another? It sounds kinda like when I shut off my Abarth when hot and the fan and cooling system continue to run for a bit afterwards, but I dunno.

 

[FISH22]

Definitely a fan-like sound. What I noticed with mine, is that it doesn't come on immediately after start up. About 15 minutes into each drive is when I hear it come on.

 

[d0wnShifT]

Might sound crazy but have you verified it's not your ventilated seats? The fans for both seats are noticeable with the music off.

 

[FISH22]

Might sound crazy but have you verified it's not your ventilated seats? The fans for both seats are noticeable with the music off.

Definitely coming from the front dash area. And yes, the ventilated seats are obnoxiously loud haha.