CT4-V Squeaking and stumbling from idle (2024 4BW)

[jadis192]

And your 100% it’s that exact part making the noise vs the TB? It’s my understanding that even when in service mode, the only part that moves is the TB. Not the WG.

You can see the arm move on the wastegate aligned with the noise. Here is a picture of a wastegate and it's arm.

The arm clearly moved during diagnostic startup. The TB is under the intercoolers, your have to remove the top of the engine to see them.

Photo of a sample wastegate attached.

LF4 engine, you can see passenger side wastegate in this photo:

 

[jadis192]

Additional video of the chirp on throttle tip-in.

 

[Weveeee]

Additional video of the chirp on throttle tip-in.

OMG. Have you basically figured out this whole thing without having to replace your TB nor Turbo!? I have an appointment setup but is this the true fix! How could it have been this simple and no dealer figured it out?

 

[ngoni]

How could it have been this simple and no dealer figured it out?

I think you give the average dealer service department far too much credit. The real sad fact is I'm sure GMs support engineers have been called in to assist a bunch of times with this and none of them have taken the time to actually figure out the problem. They just tell the dealer to keep replacing parts until the noise goes away.

 

[jadis192]

OMG. Have you basically figured out this whole thing without having to replace your TB nor Turbo!? I have an appointment setup but is this the true fix! How could it have been this simple and no dealer figured it out?

I don't want to speak for dealers, but I've documented the noise with the wastegate arm. GM should have a TSB for this, replacing turbos and TBs seems pointless.

 

[jadis192]

OMG. Have you basically figured out this whole thing without having to replace your TB nor Turbo!? I have an appointment setup but is this the true fix! How could it have been this simple and no dealer figured it out?

Let us know what the dealer does. I am editing my response as I learn more. The Arm and "bell" that I am showing in the pictures is the wastegate ACTUATOR and arm for an internal wastegate in the turbo. Now, with this being said, it is entirely possible that the wastegate within the turbo, is the problem. Which would explain why they replaced turbos for some people.

Ok, I don't want to act like a mechanic, I am really just an owner solutioning. Either way, my videos do show the noise coming when the actuator arm moves, whether the noise is from the actuator arm and bell, or from the actual wastegate itself inside the turbo who knows. Report back your findings!

 

[Weveeee]

Let us know what the dealer does. I am editing my response as I learn more. The Arm and "bell" that I am showing in the pictures is the wastegate ACTUATOR and arm for an internal wastegate in the turbo. Now, with this being said, it is entirely possible that the wastegate within the turbo, is the problem. Which would explain why they replaced turbos for some people.

Ok, I don't want to act like a mechanic, I am really just an owner solutioning. Either way, my videos do show the noise coming when the actuator arm moves, whether the noise is from the actuator arm and bell, or from the actual wastegate itself inside the turbo who knows. Report back your findings!

So of course. This week, 4.5k miles in. The noise has gone away. On its own… It was extremely prevalent during winter. I now can’t replicate it. lol. I guess this is a good thing!?

 

[CT4-Venom]

Just called to make an appointment and was told since I didn't buy the car through them, I wouldn't be able to get a loaner.

Dealership experience is as bad as people chock it up to it seems lol.

I had a similar experience with some warranty work I needed done. I had a squeak from my left front wheel every time I turned or hit a bump. They kept telling me it was the tires but after many calls to the service advisor they finally let me bring it in. I brought the car in, and they said they would need it for at least a day. I asked for a loaner and all they could offer me was to order me an uber at my cost.

They ended up having the car for a day before they could get to it and the whole ordeal two days. Not sure why I had an appointment if it took a day to get to. Turns out all three bolts holding the steering rack/gear bolts were not tight.

Man, I love the car but the service leaves something to be desired!

 

[jadis192]

On to dealer #2. Dealer #1 replaced the actuator and the sound did not disappear. I brought back in and they refused to work on the car any further until it throws a code. Total bullshit! Love this car as well, but I am looking at something else in case dealer #2 fails as well.

 

[Eww_Euros]

I have the EXACT same sound in my 25. 3300 miles on it. i noticed the sound at mile 200. took it to the dealer at 1k miles, they said that it's a normal mechanical sound, I called bullshit and still left. the car does not make the sound on cold startups. it only makes the sound after I have driven for a few miles. I want to get this issue resolved. I originally thought it was a wastegate. as I am very familiar with cars and sounds. i mentioned it to the dealer. and they said no. they even stated that they don't/haven't seen blackwings in the shop so they are unfamiliar with it. i think i am going to ask to get the blackwing master tech down here. i bet that would lit a fire under their ass.

i have a lift in my garage. so i will put the car in diagnostic mode. and see what i can see. ill report back