TorqFix

Timing chain replacement: BMW E90 N46, N42 (N42B18, N42B20, N46B18, N46B20, …)

Step-by-step timing chain replacement for the BMW E90 N46, N42: 131 steps. What to remove, in what order, and what to check after.

Workshop procedure for BMW — the exact step sequence and torque figures, straight from real workshop data.

131 steps 6 engine codes

🧭 Before you start

Fits: platform codes 118I, |, 120I, 2.0I, 316I, 316TI, 318, CI, 318I, 318TI, 320I

  • Timing position: the crankshaft or camshaft is set and locked during this job
  • Special tools named: locking pin, locking tool
  • Renewed: bolt

🔧 Engine codes this applies to

N42B18N42B20N46B18N46B20N46B20BN46B20TU2OL

📋 Procedure

Preparation and removal

  1. Balance shaft tensioning tool:
  2. Remove the spark plugs
  3. Disconnect the breather hose from the camshaft cover
  4. Lock both balance shafts
  5. Balance shaft tensioning tool:
N42B18? Steps differ between engine variants — check this job against your exact car before you commit to it. Check my car — free →
  1. Older type:
  2. Newer type:
  3. Lock the tensioner; use a locking pin
  4. Remove the ancillary drive belt
  5. Use the special tools
  6. Disconnect the connector(s) from the solenoid valve
  7. Remove the gearbox lower cover
  8. Remove the oil sump
  9. Check the position of the camshafts
  10. Inlet:
  11. Exhaust:
  12. Fit the adjustment tool
  13. Use the special tool
  14. Use the special tool
  15. Remove the flywheel locking tool
  16. Use the special tool
  17. Turn the crankshaft to TDC for cylinder 1
  18. Fit the flywheel locking tool
  19. Check that the camshafts are locked
  20. Use the special tool
  21. Remove the flywheel locking tool
  22. Remove the chain tensioner piston
  23. Remove the camshaft adjuster
  24. Remove the access plug
  25. Remove the access plug
  26. Remove the timing chain guide bolts from the cylinder head
  27. Use the special tool

Installation and checks

  1. Camshaft locking tool:
  2. Camshaft locking tool:
  3. Refit the access plug
  4. Refit the crankshaft hub
  5. Check the condition and renew if necessary
  6. Fit the centre bolt of the crankshaft gearwheel/vibration damper
  7. Refit the chain guide rail
  8. Refit the access plug
  9. Refit the inlet camshaft adjuster
  10. Renew the bolt and tighten
  11. Fit the camshaft locking tools
  12. Turn the crankshaft to TDC for cylinder 1
  13. Check the timing
  14. Refit the eccentric shaft actuator
  15. Refit the cylinder head cover
  16. Refit the spark plugs
  17. Remove the locking pin
  18. Refit the oil sump
  19. Renew the bolts
  20. Fit the ancillary drive belt pulley
  21. Refit the gearbox lower cover
  22. Refit the dipstick tube
  23. Fit the vibration damper
  24. Refit the ancillary drive belt
  25. Remove the tensioner locking tool
  26. Refit the air filter housing
  27. Refit the mass airflow meter
  28. Refill the engine oil
  29. Reconnect the battery earth cable

Other BMW procedures

Who makes these pages, and how

TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com

The story behind TorqFix →

Workshop data on this page last updated 20 Sep 2026.