Genuine 2005 BMW X3 Cylinder Head

2005 BMW X3 Cylinder Head Parts Questions & Experts Answers

• Q: How to clean and reassemble the engine block and cylinder head in N52 six sylinder engine on 2005 BMW X3?

  A: Before cleaning the engine block sealing surface, insert plugs into oil passages. Note the cylinder head gasket ID at the right front edge of the gasket. Clean the cylinder head and gasket surfaces of the engine block and timing chain housing. Remove foreign matter and liquid from bolt holes, as trapped oil or coolant can cause damage. Avoid using a metal scraper or wire brush; instead, use a hard wooden or plastic scraper or abrasive discs with an electric drill. Inspect the cylinder head for visible cracks or defects, and remove the intake and exhaust camshafts and intermediate intake levers to check for warpage using a straightedge in both longitudinal and transverse directions. Have the cylinder head tested for coolant leaks and cracks. If warped but otherwise sound, machine a maximum of 0.3 mm off the sealing surface. Reassemble the cylinder head or use a reconditioned BMW cylinder head. Ensure the two cylinder head aligning sleeves are correctly positioned and not damaged, then replace the cylinder head gasket. If the cylinder head is machined, use a special thicker gasket available from an authorized BMW dealer. Place the cylinder head on the engine block, fitting it to the aligning sleeves, and insert new aluminum cylinder head bolts of specified lengths. Use the appropriate BMW special tools to tighten the bolts in the correct sequence. Stage 3 applies to M10 bolts only, and new aluminum bolts should be used to attach the cylinder head to the timing chain housing. Use a mechanical gripper to prevent lower bolts from falling into the crankcase and ensure different bolt lengths are placed in the correct bores. Reinstall the eccentric shaft stop screw, replace the eccentric shaft magnet wheel, and reinstall the eccentric shaft sensor. Retrieve the timing chain from inside the timing chain housing, place it over the chain module, and clip the module to the lower chain rail, then reinstall the chain module mounting bolts. Use new bolts to reattach the camshaft adjustment units, noting the differences between exhaust and intake units. Lock down the camshafts with special tools, install the chain tensioner, and set the camshaft timing. If reusing the chain tensioner, drain its oil chamber and compress it slowly. No sealing ring is fitted to the chain tensioner at the factory, so use a new sealing O-ring during reassembly. The remainder of the installation is the reverse of removal, ensuring to remove locking tools, assemble the cylinder head cover with a new gasket, reattach and tighten any ground cables, reassemble the fuel rail with new O-ring seals, change the engine oil and filter, and fill and bleed the cooling system.