merc-c300

Hello, need some help trying to figure out a noise in my car.

2015 Mercedes c300 4matic

I had the wrist pin issue done months ago. And after that I been having a little taping / tick noise. In the morning when the engine is cold and ONLY WHEN I DRIVE IT medium Medium throttle. Around 1500 rpm to 2500. Goes away if do hard acceleration or go over 3000rpm also goes away when car is warm up little. I use Mobil 1 04-40. And she’ll 91 gas. Car is under warranty for 20k more miles. Took it to the dealer they said it’s normal. It’s turbo flap or something that make noise when cold and goes away when warmed up. I feel like it’s nonsense. My car has 53k miles the wrist pin job was done around 48k miles. I can’t record it cuz it’s really not noticeable in video. The camera doesn’t pick it up. Any help will be appreciated.

Sivryn

Mine does this too under the exact same conditions. On the phone the dealer said it was DI fuel noise. Sounds like cards on a bike wheel for a couple minutes in the morning. It seems loud to me so I’m going to take it in. I’ve had DI cars for years now and have never heard this noise.

diamondsilver16

Same here as well. Took mine into the dealer also and was told it was just noise from the turbo wastegate. My warranty ran out last month so hopefully it doesn't progress into something worse.

Sivryn

I recorded my noise on a drive this morning. You can hear it the whole time but it’s much more noticeable when I let my foot off the throttle in the last 5 seconds. I actually took it to the dealership and left it overnight. The mechanic said he didn’t hear it, but everyone noticed it in the recording. Sounds like the Jetsons vehicle. They couldn’t figure it out from the recording.