Start it in the Morning, for two seconds she sounds like a diesel

Welcome to 2CarPros.

A cam phaser is designed to allow the computer to control valve timing. On your vehicle, they are referred to as cam adjusters. To replace these is very involved and yes they can make a chattering sound. I attached a picture and circled the parts you questioned.

I will also tell you there is a technical service bulletin (TSB) regarding start up noise from the timing chain area which I believe what you have. The test to identify the source requires a special program/computer scanner.

Here is the TSB

2013 Mercedes Benz C 250 Sedan (204.047) L4-1.8L Turbo (271.860)
Engine noises (rattling) after engine start
Vehicle Engine, Cooling and Exhaust Engine Timing Components Timing Chain Technical Service Bulletins Engine noises (rattling) after engine start
ENGINE NOISES (RATTLING) AFTER ENGINE START

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- Engine noises (rattling) after engine start -
Topic number
LI05.10-P-058758
Version
3
Design group
05.10 Timing chain drive, toothed belt drive
Date
12-07-2016
Validity
ENGINE 271.8 EVO
Reason for change
Amended step 3 instructions of "Remedy" field.
Complaint
Noise:

A rattling noise may be heard from the area of the chain drive for approx. 2-5 seconds after engine start.

Cause
The noise can have various root causes. Refer to Remedy to perform diagnosis / repairs.

Remedy
Xentry Diagnostics provides a guided test for systematic troubleshooting:

1. Connect XENTRY/DAS

2. Work through the guided test. To do this, call up menu item "Control unit view †Type of drive - ME motor electronics - Tests - Check chain drive and engine oil level.".

3. Perform repair according to findings and WIS AR documents in DG05.

Symptoms

Symptom
Power generation / Engine noise / Chattering
Power generation / Engine noise / Clanking
Power generation / Engine noise / Rattling
Power generation / Engine noise / Clattering
Power generation / Engine noise / Pounding
Power generation / Engine management / Indicator lamp / Engine diagnosis / lit

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Let me know if this helps answer your question and if the TSB seems to match the symptoms.

Take care,
Joe

Welcome back:

First, you need to confirm that is the issue and determine which one it is. Do you have access to the scan tool mentioned in the aforementioned link? Let me know. I can provide directions for chain replacement and actuator if it is determined that is the issue. It's a lot of work and I would hate to see you do it and have the same problem.

Let me know.

Joe

Is the scanner configured for Xentry? That is Mercedes software? If it is, then you need to hook it up and follow the directions listed in my first post.

Let me know if I can help.

Take care,
Joe