11 31 051 Replacing timing chain (N20)

WARNING: This page is about a different variant/trim than selected.

Special tools required:

11 4 120
11 9 260
11 0 300
11 8 180
11 8 660
83 30 2 212 831
2 212 825

Necessary preliminary tasks:

Remove CYLINDER HEAD COVER .
Remove all SPARK PLUGS .
Remove TENSIONING DEVICE for drive belt.
Remove VIBRATION DAMPER .
Remove CRANKSHAFT RADIAL SEAL at front.
Check TIMING .
Removing OIL SUMP .

Push back the chain tensioner with the tensioning rail (1).

Secure chain tensioner using special tool 11 4 120 .

Fig 1: Pushing Back Chain Tensioner With Tensioning Rail

Engine removed:

Block crankshaft at flywheel with special tool 11 9 260 .

Attention!

To release central bolt (1), remove special tool 11 0 300.

Fig 2: Identifying Central Bolt And Special Tool (11 9 260)

Vehicles with manual gearbox:

Attach special tool 11 8 180 to manual transmission with existing transmission bolts (1).

Block crankshaft in direction of arrow with special tool.

Fig 3: Attaching Special Tool (11 8 180) To Manual Transmission

Vehicles with automatic transmission:

Block crankshaft with special tool 11 8 660.

Feed in special tool, slide screw forward and tighten.

Fig 4: Identifying Special Tool (2 222 742)

Attention!

Breakaway torque of central bolt > 600 Nm.

A 3/4 inch tool is needed to release the central bolt.

Release central bolt (1).

Tightening torque 11 21 1AZ .

Fig 5: Releasing Central Bolt

Attention!

Remove special tool (1) to release the central bolts on the intake and exhaust camshaft adjusters.

Remove INTAKE AND EXHAUST CAMSHAFT ADJUSTERS .

Order number:83 30 2 212 831

Fig 6: Identifying Special Tool

Remove CHAIN TENSIONER .

Screw in vibration absorber screws (1).

Pull out hub (2) on crankshaft forward in direction of arrow.

Fig 7: Pulling Crankshaft Hub

Open screw plug (1).

Tightening torque 11 31 8AZ .

Fig 8: Identifying Screw Plug

Release bearing journal (1) from timing chain module on cylinder head.

Tightening torque 11 31 6AZ .

Fig 9: Identifying Bearing Journal

Release screw plugs (1 and 2).

Tightening torque 11 11 7AZ .

Fig 10: Identifying Screw Plugs

Release bearing journal (1) on left and right of timing chain module for timing chain on crankcase.

Installation note:

Rinse thread of the bearing journal with brake cleaner.

Fig 11: Identifying Bearing Journal

Tightening torque 11 31 5AZ .

Release bolts (1) from timing chain module on cylinder head.

Tightening torque 11 31 4AZ .

Remove chain module with timing chain and camshaft sprocket upwards.

Fig 12: Identifying Bolts

Remove timing chain module (1) upward.

Fig 13: Removing Timing Chain Module

Attention!

Note direction of installation of camshaft sprocket (2).

Collar (see arrow) on sprocket (2) points to engine .

Incorrect assembly will result in engine damage .

Fig 14: Locating Sprocket Collar

Pull timing chain upwards until camshaft sprocket engages chain guide (1).

Install timing chain and camshaft sprocket in this position.

Installation note:

Permanently hold timing chain under tension. Timing chain may jam on chain guide (1).

Fig 15: Locating Chain Guide

Loosen sealing cap using a screwdriver.

Fig 16: Loosening Sealing Cap Using Screwdriver

Installation note:

Turn engine at central bolt until special tool 2 212 825 can be positioned in counterbalance shaft.

Secure special tool 2 212 825 to oil pump housing with screw (1).

Fig 17: Positioning Counterbalance Shaft With Special Tool (2 212 825)

Fit hub and central bolt (1).

Fig 18: Identifying Central Bolt

Remove special tool 11 4 120 .

Fig 19: Removing Special Tool (11 4 120)

Insert central bolt (1) with hub for crankshaft.

Tighten down central bolt (1).

Tightening torque 11 21 1AZ .

Install INTAKE AND EXHAUST CAMSHAFT ADJUSTERS .

Fig 20: Tightening Central Bolt

Remove all special tools.

Crank engine twice.

Check TIMING .

Replace front CRANKSHAFT SEAL .

Assemble engine.