Oiling System

If your M50, M52, or M54 engine takes a few seconds to build oil pressure after sitting, there's a good chance that your factory oil filter housing drain back valve has failed. Over time, the factory plastic check valve degrades, allowing oil to drain completely out of the housing and back into the oil pan while sitting. Every cold start essentially becomes a dry start, resulting in a loud ticking noise and causing unnecessary wear on your engine's internals.

Unfortunately, BMW does not offer this check valve as a standalone part, forcing you to purchase a costly, complete oil filter housing assembly just to fix one failed plastic component. Thankfully, our team of BMW enthusiasts took note of this common failure mode and designed a permanent, cost-effective fix.

Our Billet Oil Filter Housing Drain-Back Valve is designed as a direct-fit upgrade for your factory oil filter housing. CNC-machined from high-strength billet aluminum, this upgraded valve restores positive sealing to keep the oil filter housing fully primed. Maintaining this hydraulic prime ensures rapid oil pressure stabilization upon startup, directly mitigating dry-start bearing wear and top-end lifter starvation without requiring the purchase of a complete OEM housing assembly.

On the twin-turbocharged M57, all the oil that reaches the turbos goes through this line first. It carries pressurized oil from the engine block to the oil distribution piece, which feeds both the high- and low-pressure turbos. When the factory line’s rubber sections age and its crimped fittings start to leak, the oil spreads across the block and exhaust. The leak also puts the oil supply to both turbos at risk. This line sits deep in the engine and is hard to reach, so it’s a job you only want to do once. We built our braided distribution line to be the last one you install.

The factory line uses rubber hose sections that harden and crack with heat and age. Our version uses a PTFE inner hose wrapped in stainless steel braid, so it stays flexible and leak-free through countless heat cycles. On top of that, a black PVC shell protects the braid in the tight space around the block and keeps the factory look under the hood. Our line comes with new banjo bolts and copper crush washers. It fits in the factory location with no modifications. While you have this area apart, it’s a good time to replace our high-pressure (11427795971) and low-pressure (11427795972) supply lines too.

BMW’s M57 twin-turbo diesel uses its two turbos in stages. A small high-pressure turbo gives quick response at low RPM, and a larger low-pressure turbo takes over for top-end power. The oil line that feeds the high-pressure turbo runs right next to the exhaust manifold, which makes it one of the hottest places on the engine. After enough heat cycles, the factory rubber hose sections get brittle and crack, and the crimped fittings start to leak. You may see oil dripping onto hot exhaust parts, smell burning oil inside the car, or notice smoke from under the hood. If the leak is left alone, the turbo bearings can run short on oil and fail. Our braided supply line fixes this weak spot with a tough PTFE stainless steel line built to take the heat for good.

From the factory, this line is steel tubing joined by rubber flex sections, with an aluminum heat sleeve that holds onto oil once a leak starts. We replace the rubber with a PTFE inner hose wrapped in stainless steel braid. PTFE holds up to heat and oil far better than rubber, and the braid protects against bursts and abrasion. On top of that, a black PVC shell keeps the braid from rubbing against nearby lines and wiring, and it keeps the factory look under the hood. Our line comes with new banjo bolts and copper crush washers. It fits in the factory location with no modifications required.