Crankcase Vent Hose, Rein - E46 M3 01-04, MZ3 S54

This part is listed by BMW as BMW part number 11157831311 (11 15 7 831 311) and is described as a crankcase oil vent hose from the valve cover to the intake manifold on 2001-2004 E46 M3 and MZ3 (S54). The oil separator and vent tube may be cleaned but a complete replacement is the only sure way of getting the S54 oil vent system back to normal operation.

This plastic vent hose carries oil vapor from the cylinder head/valve cover to the intake manifold where it is then mixed with the intake air and burned in the engine. This is how the S54 crankcase vent system is supposed to work. But over tens of thousands of miles, the oil separator in the valve cover and this vent tube on top of the engine get clogged with oil and carbon and this reduces its effectiveness. A clogged or malfunctioning crankcase vent on the S54 will lead to excessive oil consumption (too much oil is getting burned), fault codes for fuel trim, misfires, and rough running.

This is a S54 oil vent hose manufactured by Rein Automotive (CRP) - a front-line supplier of original equipment, private label, and in-house engineered replacement parts. Rein replacement products meet or exceed all of BMW's original design, fitment, and performance requirements and they carry out testing with ISO and German TUV for quality control. Rein parts are the best alternative to more expensive Original BMW parts because they are virtually identical without the inflated price tag. This part has a two year warranty.