The BMW B58 is one of the most beloved modern engines — smooth, responsive, and capable of high power levels while still being reliable. However, a known issue affects many B58 engines built roughly between 2018 and 2022: the engine’s variable-pressure oil pump contains a plastic internal ring that can crack or degrade over time. When that part fails, the oil pump can no longer regulate pressure correctly, which can trigger oil pressure warnings and even put the engine at risk if not addressed.

🔍 What Happens and Why It Matters

The oil pump on affected B58 engines uses a plastic component in its internal mechanism that, under certain conditions, can become brittle and crack. This often shows up as:
Oil pressure warning light on the dash
Unstable or incorrect oil pressure readings
Failed oil level measurements
Engine entering limp mode due to low pressure detection

Without proper oil pressure, critical components like bearings and camshafts can be starved of lubrication, leading to expensive damage. The issue tends to surface more often in colder climates, extended high-load operation, or when the wrong oil viscosity (thicker than OEM spec) is used.
⚙️ Who’s Affected and What’s Been Changed

This oil pump issue is most common on B58 engines produced from about 2018 until a design update around 2022. BMW revised the internal pump design during this period, replacing the problematic plastic part with a metal component that significantly reduces the risk of failure. If your engine is from after this update, it’s far less likely to suffer from this issue — but it’s still worth checking the part number to be certain.

💡 What You Can Do

If your B58 falls into the affected build years, here are practical steps you can take:
Watch for warning signs — never ignore an oil pressure light.
Use the correct oil — BMW specifies 0W-20 for most B58 applications; thicker oils can mask pressure changes and stress pump components.
Check your pump part code — ask a shop or dealer to confirm whether your car has the updated metal-internal pump or the older plastic version.
Upgrade early if needed — performance shops and specialists offer upgraded oil pumps that use stronger internals and often improve high-RPM stability.

Below you will find a video of someone who takes it apart to check why it fails.