Disconnect the negative battery cable, ensuring to read the battery disconnection cautions beforehand. Remove the upper engine cover and air filter housing, then use BMW special tools to loosen and remove the cooling fan and clutch from the coolant pump, noting that the 32 mm cooling fan nut has left-hand threads. Remove the fan cowl from the radiator, and with the engine fully cooled, take off both cylinder head covers and remove the spark plugs, plugging the bores to prevent debris from entering the engine. Loosen and remove the primary timing chain tensioner from the right upper Timing Cover, raise the car safely, and remove the lower engine cover. Drain the engine coolant, catching any dripping coolant with shop towels to avoid contamination of accessory belts. Detach the coolant hoses from the coolant pump and thermostat assembly, and working at the left upper Timing Cover, remove the left camshaft sensor and left VANOS solenoid, ensuring to catch any dripping oil. Use a deep socket to remove the left VANOS solenoid and set it aside, then repeat the process for the right camshaft sensor and right VANOS solenoid. Detach the air duct to the secondary air injection check valve, remove the manifold mounting bolts, and lift out the manifold. Unbolt the dipstick tube and remove both upper Timing Covers. For installation, clean the gasket residue from the upper Timing Covers and cylinder head covers, applying sealant to the joints. Install the left Timing Cover with a new gasket, tightening the fasteners finger tight, and use a spacer tool in place of the left cylinder head cover gasket. Tighten the left cylinder head cover fasteners uniformly, then reinstall the cover using new gaskets and additional sealant at the half-moon cutout corners. Replace the sealing O-ring in the right cylinder head, apply sealant to the joints, and position the right upper Timing Cover with a new gasket, tightening the fasteners finger tight. Use a spacer tool for the right cylinder head cover gasket, install the cover, and tighten the fasteners uniformly. Reinstall the cylinder head cover with new gaskets and additional sealant, then reinstall the VANOS solenoids, clean the sealing surfaces, lightly oil the sealing lip, and reattach the electrical harness. Reinstall the left and right camshaft sensors, install the primary timing chain tensioner with a new sealing washer, and complete the installation in reverse order of removal, ensuring to use new sealing O-rings for the secondary air injection manifold and reattach the cooling system hoses before filling and bleeding the cooling system.
Posted by BMWPartsDeal Specialist 
