Timing E30/E36 Camshafts and Installing VANOS: A Step-by-Step Guide
Step 1: Set Engine to Top Dead Center (TDC)
- Ensure the engine is at TDC.
- Install the TDC pin into the locking position to hold the flywheel steady.
- Lock the camshafts using the camshaft locking tool for proper alignment and timing of the camshafts and VANOS.
Step 2: Inspect Exhaust Camshaft Sprocket
- Check the sprocket for wear or damage, especially on the gear teeth and inner mounting slots.
Step 3: Install the Exhaust Camshaft Sprocket
- Mount the sprocket onto the exhaust camshaft.
- Ensure the mounting holes on the camshaft flange are visible through the sprocket slots.
- Position the holes toward the left side of the slots.
- Adjust the sprocket as needed, as it may take multiple attempts to get the correct alignment.
Step 4: Replace the Lower Chain Tensioner
- Locate the lower chain tensioner on the lower right side of the engine block.
- Remove the tensioner and replace it with a tensioner tool to keep the chain tight while timing the cams.
Step 5: Install the Tensioner Tool
- Replace the spring-loaded tensioner with the tensioner tool. This tool provides the proper tension needed for accurate camshaft timing. Hand-tighten the tool for now.
Step 6: Remove the Old Chain Tensioner
- Use a socket to remove the tensioner. Be aware that it is spring-loaded and will pop out when released.
Step 7: Inspect the Tensioner Assembly
- The tensioner assembly consists of a plunger, spring, cap, and sealing ring. Remove and inspect all parts.
Step 8: Install the Chain Guide
- Install the center plastic chain guide.
- Torque the bolts to 10 Nm. Avoid over-torquing as it could break the bolts.
Step 9: Reinstall the Top Chain Tensioner
- Reinstall the top chain tensioner and tighten the bolts to 10 Nm. Replace the tensioner if your engine has more than 80,000 miles.
Step 10: Install the Camshaft Sensor Cap
- Place the camshaft sensor cap onto the intake camshaft. This cap triggers the camshaft position sensor.
Step 11: Install the Thrust Washer on the Intake Camshaft
- Install the thrust washer onto the intake camshaft using the special studs.
- Torque the studs to 20 Nm.
Step 12: Attach the Intake Sprockets and Chain
- Attach both intake sprockets and the chain.
- Ensure the exhaust sprocketโs cup faces outwards and the intake sprocketโs cup faces inwards. Both sprockets should be mounted flush.
Step 13: Install the Sprocket and Thrust Washer
- Tighten the nuts on the intake camshaft to 10 Nm. Verify that the inside sprocket rotates freely by about 20 degrees.
Step 14: Secure the Exhaust Camshaft Sprocket
- Hand-tighten the screws onto the exhaust camshaft sprocket for now.
Step 15: Prepare for VANOS Installation
- Ensure the camshafts, chain, and sprockets are installed properly before installing the VANOS unit.
Step 16: Test the VANOS Unit
- Pull out the gear plunger of the VANOS unit. It should extend smoothly and retract without resistance.
Step 17: Apply Sealant to VANOS Mounting Points
- Apply silicone sealant around the alignment pins for the front VANOS seal on both sides of the engine.
Step 18: Install the VANOS Unit
- Install a new seal onto the front of the cylinder head.
- Rotate the front sprocket/chain assembly clockwise and ensure the VANOS plunger is fully retracted before placing the VANOS unit onto the cylinder head.
Step 19: Engage the VANOS Gear
- Rotate the spline shaft on the VANOS unit until the gears engage with the sprocket.
- Rotate the sprocket/chain assembly counterclockwise while pushing the VANOS unit onto the cylinder head.
Step 20: Secure the VANOS Unit
- Reinstall the main mounting bolt and engine lift ring.
- Tighten the VANOS housing and clean off any excess sealant.
Step 21: Adjust Chain Tension
- Pull out the retaining pins and reapply tension to the chain.
- If the tensioner is sluggish, replace it.
Step 22: Tighten the Chain and Sprockets
- Tighten the tensioner tool to 1.3 Nm to remove slack from the chain.
- With the tool still in place, tighten the four nuts on the exhaust sprocket to 15 Nm.
Step 23: Replace the Tensioner Tool
- Remove the tensioner tool and install the real chain tensioner, ensuring correct alignment with the ramp inside the engine.
Step 24: Final Adjustments
- Remove the camshaft holding tool and the flywheel locking tool.
Step 25: Complete the Installation
- Connect the VANOS oil line and electrical control line.
- Reinstall the valve cover with a new seal and reinstall the ignition coils.
Your camshafts are now timed, and the VANOS unit is installed correctly!