It’s been a journey, but finally, the replacement tube arrived, allowing me to restore my Mercedes Air Filter system as closely as possible to its original design. I wanted to share an update on this process, especially regarding the mercedes air filter and its crucial role in engine health. With the system now fully operational, the oil-filled air filter is no longer experiencing oil overflow. The engine oil level remains consistent – a welcome change from before when it was diminishing as oil ended up in the air filter’s oil bath. Similarly, the oil level within the oil bath air filter itself is stable. Interestingly, I haven’t noticed any significant change in engine performance. I believe this is because the previously installed, incorrect breather hose was positioned too deeply into the T-piece on the air inlet, effectively obstructing the secondary entrance.
I’ve attempted to illustrate this blockage in Photo 1.
Photo 2 displays the currently configured system. ‘A’ denotes the connection at the top of the crankcase, ‘B’ is the T-piece situated on the air inlet, and ‘C’ represents the line leading to the “dirty” side of the mercedes air filter.
Photos 3 and 4 showcase the system after installation in the vehicle.
I’ve sealed off the additional tubing connection that was present in the oil filler cap on the crankcase, as it’s no longer needed with the corrected system.
The only deviation from the original setup I can identify is that the connection from the T-piece should ideally route to the “clean” side of the inlet air system. It should be connected in close proximity to the throttle control on the air inlet. Instead, in my current configuration, it’s directed back to the base of the oil bath mercedes air filter housing, specifically on the “dirty” side, although positioned considerably above the oil level. My understanding is that the engine’s suction force draws air through this tube, moving outwards from the crankcase. Initially, I was concerned that this setup might allow unfiltered air to enter the crankcase. However, the suction is so powerful in the opposite direction that this scenario seems highly improbable. I would greatly appreciate any insights or opinions on this aspect, especially if anyone believes my understanding is flawed.
Since completing this work, I’ve undertaken several drives of around 1.5 hours each, and everything appears to be functioning correctly. There’s no noticeable oil consumption, no exhaust smoke (except a minimal puff at startup, which was present before), and the engine power and overall performance remain consistent. My oil pressure gauge consistently reads a solid 3 bar during driving. At idle and in neutral (when stopped at traffic lights), it stabilizes just below 2 bar. Therefore, I am confident that the system is operating as intended, even if it’s not an absolutely perfect 100% replication of the original factory configuration.
Many thanks to everyone who offered their valuable advice and suggestions throughout this process!
