jonathan358

Anyone else experience rattling or vibrations around ~3rd/4th gear when hitting the turbo at medium throttle?

I hear the rattling when my windows are down coming from the engine bay.

Doesn't seem normal. Never occurs at very low or high gears either.

Gungaslow

ItalianJoe1

Using good gas? That sounds like detonation to me.

There is a bulletin about updated software for wastegate noises on certain 400/450 cars, but your 2018 has to have the newer software already.

jonathan358

Thanks for the responses, it does sound like wastegate flutter. Idk if it is a problem but ill have my dealer check for updates.

Also, it does not sound nearly as loud as the WRX "wastegate flutter" youtube videos. More like this: (EDIT: NOT LIKE THIS)
where it slowly builds up as boost increases.

Gungaslow

jonathan358

Still have not taken it to a dealer just yet though I think I may have pinpoint the exact timing of the rattling, it seems to happen JUST before each upshift; particularly in Sport mode.

I don't know if it is the wastegate flutter anymore...

Any new clues as to the problem? Thanks in advance.

jonathan358

Sorry to revive an old thread but the service manager at my local MB dealership speculates that the noise is coming from the wastegate valve being slightly loose when almost closed. Apparently it is causing the gate to vibrate.

As the weather gets cooler, I can hear it quite audibly and it happens basically every drive. Quite annoying but the SM states that the bulletin does not recommend any fixes or replacing of parts.

I bought the car and don't want to have problems down the line so I am still concerned, not to mention the noise is a bit embarrassing...

Having something vibrate will cause it to erode eventually and the sanded-down particles would enter the turbos and into the cylinders.

On a side note, I want to thank Gunga and Joe for helping me diagnose the problem and bringing this up with service in the first place!

Shrief

Hello Johnathan, I have a very similar problem to yours. Took my car in for service but I got "the car sounds normal to us" response. I'm taking it in to another dealer on Monday to see what they have to say.

Have you eventually got yours fixed?

Cheers,
Shrief

jonathan358

No, I've taken it to 2 dealers so far. None can fix...

Sivryn

Is this what you are hearing? Only here it on cold starts for ten minutes at low RPMs. Sounds like a card on bike spokes. You can really hear it in the last 5 minutes of this video.

jonathan358

Not at all, the problem is confirmed to be wastegate-related.

Your problem sounds more like a fan motor rattling, which I also have...

alexasa

iTrader: (1)

that is normal Sivryn - although not sure why you can hear it. i could only hear this when removing the engine bay seal.

GuardianVA

Is this close to the sound you're hearing?


You compared it to the sound in a video early in this thread, and hearing it I immediately thought of wastegate rattle.

jonathan358

Yeah this is a great video, nearly identical. It has been confirmed to be the wastegate rattle.

I have yet to find a dealer who will help me fix it but with this video hopefully they can pinpoint exactly what sound to look for and what to start fixing right away. To be honest, I was just going to get a tuner shop to help me take out the engine to get to the turbos and have them extend the preload. But that will cost me $$$.

Muskokamarc

Has anyone had this resolved by their dealership? What were the steps taken? I've noticed my C43 makes a similar rattle sound to the video of that 3 series video above. It always seems worse in the summer.

I did a road test with a tech from the dealership, and he said it has to do with the turbo. Last summer they replaced the passenger side turbo but the noise remained. When i went back this past week we did a road test and when we revved the car we could the rattle sound loud and clear. He adjusted the actuator on the driver side turbo while we were pulled over during the road test and the noise stopped when we revved the car. He said it was just a temporary switch and then had to put it back.

Dave992

I’ve just purchased a 2017 C43 and noticed a metallic rattle 1 day in. I’ve put 500 miles on the car since and the rattle has got worse and all I can think is play in the wastegate, there’s a also a strong smell of fumes in the engine bay when in idle which could be the wastegate failing to seal. Hoping to get a full diagnostic report in the next week.