CT4-V 4BW issues the dealer can’t figure out

[Sjobr57]

Hey everyone, I’m looking for some help here and wondering if other people have run into these issues as well.

My ‘24 4BW has two obnoxious issues the dealer is struggling to diagnose but also doing a terrible job even trying to duplicate the concern. First off, the AC will blow ice cold for a few minutes then fluctuate in temperature as if I’ve turned off the AC button and left the HVAC in LO, then the cold ac will start again. Vehicle speed, blower speed, ambient temperature, set to auto, nothing effects this and it is fully intermittent. Dealer evacuated and recharged AC (no leaks), reprogrammed the BCM and are now saying they can’t duplicate it.

Second is intermittent clunk from the rear. I’ve seen a couple other guys with a rear clunk fixed with replacement rear shocks, which my dealer did, but the clunk is still there. Happens 10-30mph, louder in sport or track suspension modes. I’ve checked torque on every nut and bolt in the rear suspension and nothing was loose, no visual damage or wear.

These issues are driving me crazy and making me consider trying to get the car bought back, which I don’t want to do because I love this car. But I’m really hoping for someone with similar concerns on their 4BW and any advice is welcome. Thanks in advance.

 

[1Evil55]

Can't help with the A/C issue but the clunk could be a bad shock? How many miles? Any leakage shown on the shocks?

 

[Sjobr57]

Car has 9000 miles on it. The dealer actually replaced both rear shocks yesterday, said the noise was gone, and I heard it almost immediately on the way home. New shocks look good, no leaks at all.

 

[DonD]

Good luck, beyond aggravating. Don

 

[BklynUSA]

Hey everyone, I’m looking for some help here and wondering if other people have run into these issues as well.

My ‘24 4BW has two obnoxious issues the dealer is struggling to diagnose but also doing a terrible job even trying to duplicate the concern. First off, the AC will blow ice cold for a few minutes then fluctuate in temperature as if I’ve turned off the AC button and left the HVAC in LO, then the cold ac will start again. Vehicle speed, blower speed, ambient temperature, set to auto, nothing effects this and it is fully intermittent. Dealer evacuated and recharged AC (no leaks), reprogrammed the BCM and are now saying they can’t duplicate it.

Second is intermittent clunk from the rear. I’ve seen a couple other guys with a rear clunk fixed with replacement rear shocks, which my dealer did, but the clunk is still there. Happens 10-30mph, louder in sport or track suspension modes. I’ve checked torque on every nut and bolt in the rear suspension and nothing was loose, no visual damage or wear.

These issues are driving me crazy and making me consider trying to get the car bought back, which I don’t want to do because I love this car. But I’m really hoping for someone with similar concerns on their 4BW and any advice is welcome. Thanks in advance.

Hey everyone, I’m looking for some help here and wondering if other people have run into these issues as well.

My ‘24 4BW has two obnoxious issues the dealer is struggling to diagnose but also doing a terrible job even trying to duplicate the concern. First off, the AC will blow ice cold for a few minutes then fluctuate in temperature as if I’ve turned off the AC button and left the HVAC in LO, then the cold ac will start again. Vehicle speed, blower speed, ambient temperature, set to auto, nothing effects this and it is fully intermittent. Dealer evacuated and recharged AC (no leaks), reprogrammed the BCM and are now saying they can’t duplicate it.

Second is intermittent clunk from the rear. I’ve seen a couple other guys with a rear clunk fixed with replacement rear shocks, which my dealer did, but the clunk is still there. Happens 10-30mph, louder in sport or track suspension modes. I’ve checked torque on every nut and bolt in the rear suspension and nothing was loose, no visual damage or wear.

These issues are driving me crazy and making me consider trying to get the car bought back, which I don’t want to do because I love this car. But I’m really hoping for someone with similar concerns on their 4BW and any advice is welcome. Thanks in advance.

 

[BklynUSA]

My previous ct5v non Blackwing had a similar problem with the a/c where it would start blowing warm air after about 15 minutes of driving no matter what setting and would work again only after the car sat for hours. The dealer changed a temperature sensor behind the dash/glovebox area and all was well afterwards. My current Ct4V Blackwing has the same noise at the right rear, they changed the shock twice, clunk is still there, all is tight. I may have them change the sway bar link next. It's annoying.

 

[Sjobr57]

My previous ct5v non Blackwing had a similar problem with the a/c where it would start blowing warm air after about 15 minutes of driving no matter what setting and would work again only after the car sat for hours. The dealer changed a temperature sensor behind the dash/glovebox area and all was well afterwards. My current Ct4V Blackwing has the same noise at the right rear, they changed the shock twice, clunk is still there, all is tight. I may have them change the sway bar link next. It's annoying.

Thanks for the reply. I’m hoping my AC fix is something simple like that. I agree the clunk is infuriating, mine is way louder in sport or track suspension modes, not sure if yours is the same?

I have an appointment next Tuesday so I will update you if I have any positive results!

 

[Blackwing16]

Rear clunk could maybe be an issue with the parking brake not being calibrated properly. Basically there might be too much space between the rotor and parking brake pad, which allows for movement and will create a thudding sound. Easy way to test is to turn the parking brake off and the try to pull on the parking brake calipers and see if it separates easily with hand pressure. Will make a similar noise to the attached video.

 

[DCV]

It could be the parts of the shock assembly that mount it to the chassis. There is some sort of shock bushing on top that usually gets transferred over with a new shock. I had a clunk like that and it was the left rear shock. Also I’d check to make sure the battery is properly secured. It’s in the trunk and if the clamp that holds it down is loose, you might get a clunk. Also could be rear cradle bushings or loose bolts, or as said rear sway bar links loose. They should put it on a rack and literally start grabbing things and shake to find it.

 

[BklynUSA]

Thanks for the reply. I’m hoping my AC fix is something simple like that. I agree the clunk is infuriating, mine is way louder in sport or track suspension modes, not sure if yours is the same?

I have an appointment next Tuesday so I will update you if I have any positive results!

Yes, mine is much louder in sport and track mode.

 

[Sergio]

On another car I had a clunk, thought it was the sway bar links and changed them. Didn’t fix it. Changed the sway bar bushings and the clunk was gone.

Don’t know how they could be bad on yours with only 9000 miles.

Is there another dealer you can have look at it?