kmccarthy16

My 08 R350 makes a load rattle only when I start the car for the first time, subsequent starts the same day it does not rattle. The sound last for just a couple seconds. Thoughts?

BlackML550

The first thing that will come to everyone's mind will be a stretched timing chain. Rattle on first start is the classic symptom. Assume you car is gas and not diesel?

Search the forums including W164 and X164 and even W211. All used the same engines. The M272 is well known for this issue prior to mid 2008. See the attached bulletin from MB that specifies the engine number ranges of engines that are impacted by the balance shaft issue.

Ihor

The rubber ring needs to be replaced
GENUINE MERCEDES Engine Oil Pump O-Ring 0149973148 / A0149973148 | eBay