NHTSA Complaint #11515411 — 2017 MERCEDES-BENZ C350E

I have a 2017 C350E with 69K miles. Dealer wants $2900 to fix the Crankcase Ventilation Valve. The part that needs to be replaced costs about $600 with lot of labor time involved (~$2500). The part number is 274090560084. The C350E has a 15 year emissions control warranty in California that is supposed to cover "all" emissions control related parts, but Mercedes Benz USA doesn't seem to think this is part of the emission control system. I have done some research and it appears that "crankcase ventilation" is a necessary function of the engine because "blow-by" fumes would build up in the crankcase if it were not ventilated. These "blow-by" fumes used to be vented straight to the exhaust in older cars, but in the 1960's they started to recirculate them with the PCV system back into the intake manifold to limit the emissions. The function of this part seems to do the same thing a PCV system.