Dramonx

Hello all -

Recently I purchased a 2023 C63s (Brand New),
I have not driven the car hard yet due to the break in period… However, temptation finally hit me once surpassed 600 miles thinking all should be “ok”
And I have gradually started pushing the gas.

Now straight to the point - I have noticed every time when the exhaust valves are open (Either overriding manual with Comfort mode, or Sport+ mode) - When I go to accelerate or hit the gas hard I hear a clicking / grinding noise. Not sure if anyone has had this problem? — Everything else has been running great with no issues just this.

I will note again, this only happens when the exhaust valves are open.

I had a couple friends tell me that it’s just the exhaust airflow and combustion chamber working within and that it’s ok.

Below YT short link - The sound is a little faint, but you can hear it with volume up.

https://youtube.com/shorts/8Z-wissNldA?si=dwZXe_dbZh2cZnqn

Any input in regards to this? // Is it normal?

superswiss

Well, the break in instructions say explicitly not to do this until you hit 1000 miles, but your car and your decision. Where exactly do you hear this coming from? If I accelerate hard I don't hear much other than the engine and the exhaust roar, so if it's a clicking or grinding it has to be somewhat loud to be heard over the engine/exhaust noise. The exhaust valves are a common source of noise, though, and they open at various degrees depending on rpm, so if you accelerate hard they will open fully, but are only open partially for moderate driving even if you open them. Can't say I have a clicking/grinding noise when going WOT. I had mine greased at one point, because they made noise when turning off the engine when they closed. That's the common issue, but they can make noise at any point. Wouldn't necessarily expect it on a brand new car, though, unless the factory forgot to grease them.