BMW's B38/B48/B58 modular engine family — found across everything from the 1.5T three-cylinder to the 3.0T inline-six in current 1/2/3/4/5 Series, X1/X3/X5, Z4, and Supra/Toyota applications — uses a VANOS variable valve timing system with a central retaining valve inside each camshaft sprocket. That valve uses an unusual 22mm 16-point pattern that a standard socket won't grip properly, and it's the gatekeeper for VANOS actuator service, camshaft removal, and timing chain work on these engines.
Tool You'll Need
- BMW VANOS Camshaft Socket, 22mm 16-Point — matches the central valve's unique drive pattern for clean removal and installation
You'll also need a camshaft locking/holding tool appropriate for your specific B-series variant, a torque wrench, and standard hand tools for the covers and accessory drive in the way.
Why the Socket Pattern Matters Here
The central VANOS valve inside the sprocket is under spring tension and has to be held square while breaking it loose — a standard hex or a worn socket that doesn't fully engage the 16-point pattern will slip and round it off, at which point you're looking at extraction rather than removal. This is a case where the specialty socket isn't a convenience, it's the only way to do the job without damaging the part.
Step 1: Establish Correct Camshaft Position
Before touching the central valve, confirm the camshaft is in the position specified for your engine code and job (timing chain service, VANOS actuator replacement, or camshaft removal each may call for a slightly different reference position) using the appropriate camshaft locking or holding tool for your engine.
Step 2: Access the Sprocket
Remove whatever covers, mounts, or accessories stand between you and the camshaft sprockets — access varies meaningfully between the 3- and 4-cylinder B38/B48 and the inline-six B58, so confirm your specific procedure before starting.
Step 3: Fit the VANOS Socket
Seat the 22mm 16-point socket fully onto the central valve, confirming it sits flush and square before applying any turning force.
Step 4: Break the Valve Loose Carefully
This valve is spring-loaded internally. Apply steady, controlled force rather than a sharp jerk, and be ready for it to release under some internal spring pressure once it breaks free — keep the socket square to the valve through the entire process.
Step 5: Service What You're There For
With the central valve out, proceed with your actual job — VANOS actuator replacement, camshaft sprocket service, or timing chain work — following the specific procedure for your engine code and camshaft locking method.
Step 6: Reinstall and Torque
Reinstall the central valve using the same socket, torqued to the factory spec for your engine code, and confirm the camshaft locking tool still shows correct position before releasing it.
Step 7: Reassemble and Verify
Reinstall covers and accessories, rotate the engine through its normal check procedure, and confirm no cam-correlation or VANOS fault codes appear on startup.
Common Mistakes
- Using a standard hex or worn socket — rounds off the central valve fast; this is exactly the scenario the correct 16-point socket exists to prevent
- Not accounting for spring pressure — keep control of the tool as the valve releases
- Skipping engine-specific camshaft position confirmation — B38, B48, and B58 have real procedural differences; don't assume one covers all three
- Rushing reassembly without a startup fault-code check — catch a timing issue before you've driven it, not after
See our full BMW tool lineup for more modern BMW engine service essentials.