MrGreedy
MB Enthusiast
I have a 2010 E350 CDI W207. So it should be the same engine.
I cleaned the mixing duct last week when I replaced the intake swirl flap actuator and the oil cooler seals.
It was quite dirty even with EGR delete by map.
Hi Tommy
I would have a guess that if you have an EGR delete, but it's still getting dirty, then the EGR valve isn't seating correctly and remains open a tiny fraction. A blanking plate might be an option to solve this (not usually necessary with a part that operates correctly i.e. remains closed).
If you have iCarsoft or similar, you might be able to interrogate to see if it is recording a position error.