W213 E63s RMS Leak
Just recently installed the E63 motorsports dual catch can in hopes of preventing any RMS leaks in the future. Time will tell.
Does anyone know if the majority of RMS failures are due to excessive positive crankcase pressure or negative (vaccuum) pressure.
I recently measured my crankcase vaccuum at warm idle of ~16 in of water (~1 in of Hg) which from what I have researched is within normal engine parameters. Curious if anyone has seen or measured or is aware of RMS failure due to excessive crankcase negative (vaccuum) pressure. If so, what values would be considered excessive and be at risk sucking in oil seals vs pushing them out.
-5” Hg is normal on the current gen EA839 2.9TT Porsche engine. Quite high crankcase vacuum at idle measured at the oil fill cap. The fill cap is sucked onto the fitting and idle speed at idle speed is unstable with the fill cap removed while the engine is running.
The entire crankcase ventilation situation with modern engines is not figured out yet by car companies.
Current gen German engine oil-vapor separators have a more sophisticated operating principle than in the past but, as usual, the car companies are tying to solve a NASA-level problem using $0.79 parts. The result is failed rear main seals on $180k AMGs because of the use of crummy cheap oil-vapor separators.
Last edited by chassis; Aug 23, 2024 at 09:00 PM.
not pushed out given the theory that clogged oil separators cause RMS to blow out.
-5” Hg is normal on the current gen EA839 2.9TT Porsche engine. Quite high crankcase vacuum at idle measured at the oil fill cap. The fill cap is sucked onto the fitting and idle speed at idle speed is unstable with the fill cap removed while the engine is running.
The entire crankcase ventilation situation with modern engines is not figured out yet by car companies.
Current gen German engine oil-vapor separators have a more sophisticated operating principle than in the past but, as usual, the car companies are tying to solve a NASA-level problem using $0.79 parts. The result is failed rear main seals on $180k AMGs because of the use of crummy cheap oil-vapor separators.
blown out (away from the engine side) or sucked in (towards the engine side). I saw one picture "the leaky seal" that appeared to
show a sucked in RMS.
The Best of Mercedes & AMG
https://mbworld.org/forums/w213-amg/...ml#post9023470
Last edited by PeterUbers; Sep 1, 2024 at 12:49 PM.
OVS replacement would be "easy" if the engine is removed. I don't believe engine-out is required for RMS replacement.
OVS location at the front of a V8 engine generally means difficult access relative to radiator and intercoolers. DIY-able but time consuming. OVS parts are relatively cheap in the big picture, the cost for this job is related to the time for disassembly and reassembly of the many parts in a tight space.




but separators were just shy of 5k for mine









