Remove/install cylinder head

AR01.30-P-5800MSC

Remove/install cylinder head

30.03.2020

Engine

256.9 in model 167

Modification notes

23.08.2019

Note added.

Operation step 15

27.02.2020

Screw, cylinder head to crankcase/timing case

BA01.30-P-1004-01MRT

1

Cylinder head

5

Bracket

2

Support plate

6

Chain tensioner

3

Coolant feed pipe

8

Gear

4

Screw

1

Cylinder head

10

Cylinder head bolts

9

Bolts

 Caution

Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil

Wear protective gloves, protective clothing and safety glasses.
Do not fill engine oil into beverage containers.

AS18.00-Z-0001-01A

 Warning

Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.

Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers.
Wear protective gloves, protective clothing and safety glasses.

AS20.00-Z-0001-01A

Topical note

Notes on threaded connections fastened using a tightening angle-based tightening process

AH00.00-P-0020-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

 

Remove/install

1

Remove camshaft housing.

AR05.20-P-6997MSC

 Installation: Only install upper engine cover and lower engine compartment paneling after the performing a leak test.

2

Remove exhaust gas turbocharger with exhaust manifold.

AR09.40-P-6036MSC

3

Remove coolant return flow line for exhaust gas turbocharger.

AR20.20-P-1050MSC

4

Release and disconnect electrical connector at coolant temperature sensor (B11/4).

AR15.60-P-2712MSC

5

Remove bracket (5) from cylinder head (1).

 Screw, electrical connector bracket to cylinder head

*BA15.18-P-1004-01MRT

6

Remove support plate (2).

 Screw, shield to fuel high-pressure pump housing/support plate

*BA07.02-P-1006-01MRT

 Screw, support plate above fuel high-pressure pump to cylinder head

*BA07.02-P-1004-01MRT

7

Remove coolant feed pipe (3).

 Installation: Replace sealing ring.

 Screw, coolant feed pipe to cylinder head/crankcase

*BA20.20-P-1001-02MRT

8

Remove screw (4).

 Screw/bolt, thermostat coolant connection pipe to cylinder head

*BA01.30-P-1010-01MRT

9

Remove spark plugs.



AP15.10-P-1580E

10

Remove chain tensioner(6).

AR05.10-P-7800MSC

11

Remove gearwheel (8).

AR05.10-P-7760MSC

12

Remove top slide rail.

AR05.10-P-8421MSC

13

Remove screws (9) in reverse order of tightening procedure.

Tightening procedure for cylinder head bolts

AR01.30-P-5800-01MRT

 Screw, cylinder head to crankcase/timing case

*BA01.30-P-1004-01MRT

14

Remove cylinder head bolts (10) in reverse order of the tightening procedure.

Tightening procedure for cylinder head bolts

AR01.30-P-5800-01MRT

 Screw, cylinder head to crankcase/timing case

*BA01.30-P-1004-01MRT

15

Remove cylinder head (1).

General information on checking valves, valve seats and valve guides

AH05.30-P-1000-02SZ

 Aid of helper required.

16

Remove cylinder head gasket.

 Installation: Replace cylinder head gasket.

17

Remove hydraulic valve play compensation elements.

AR05.00-P-2013MSC

18

Remove valves.

When replacing the cylinder head (1).

AR05.30-P-3511MSC

19

Remove terminal strips of the exhaust manifold.

When replacing the cylinder head (1).

Tightening pattern for turbocharger

AR09.40-P-6020-10MRT

 Screw, exhaust manifold (exhaust gas turbocharger) strip clamp to cylinder head

*BA14.10-P-1002-02MRT

20

Remove coolant temperature sensor (B11/4).

When replacing the cylinder head (1).

AR15.60-P-2712MSC

21

Remove engine lifting lugs.

When replacing the cylinder head (1).

 Bolt, lifting eye to cylinder head

*BA01.30-P-1009-01MRT



Clean

22

Clean sealing surfaces of cylinder head (1), timing case cover, and crankcase.


Do not use any sharp-edged tools or abrasive paper.
Sealing surfaces will otherwise be damaged.

Loctite 7063 (400 ml) cleaning spray

*BR00.45-Z-1046-04A

Loctite 7200

*BR00.45-Z-1038-04A

23

Cover threaded holes of cylinder head bolts (10) and bolts (9) in crankcase with a rag and blow out with compressed air.



Check

24

Check sealing surfaces of cylinder head (1), timing case cover and crankcase for cracks and unevennesses.


Do not rework cylinder head (1) and crankcase (surface grinding).
The permissible production tolerances will otherwise be exceeded.

 Tightening of the cylinder head bolts (10) compensates a slight distortion of the cylinder head (1) in the longitudinal or transverse direction.

If cracks or unevenness are present,



Replace corresponding component.

25

Check cylinder head bolts (10).

AR01.30-P-5800-03MRT

Cylinder head bolt

*BE01.30-P-1001-04B

26

Install in the reverse order.

27

Change engine oil and oil filter element.



AP18.00-P-0101MRT

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

28

Carry out engine test run and check engine for proper operation and leak tightness.

29

Install upper engine cover.

AR01.10-P-2405MSC

30

Install lower engine compartment lining.

AR61.20-P-1105ME

Cylinder head/cylinder head bolts

Number

Designation

Engine 256

BE01.30-P-1001-04B

Cylinder head bolt

Thread diameter

M

11

Length (L) when new

mm

158 0,5

Length (L)

mm

159,5

For picture, see

-

 Cylinder head

Number

Designation

Engine 256.9

BA01.30-P-1004-01MRT

Screw, cylinder head to crankcase/timing case

M8

Nm

20

M11

Stage 1

Nm

10

Stage 2

Nm

40

Stage 3

°

90

Stage 4

°

90

Stage 5

°

90

 Cylinder head

Number

Designation

Engine 256.9

BA01.30-P-1009-01MRT

Bolt, lifting eye to cylinder head

Nm

29

 Cylinder head

Number

Designation

Engine 256.9

BA01.30-P-1010-01MRT

Screw/bolt, thermostat coolant connection pipe to cylinder head

Nm

8

 High pressure fuel pump, high pressure fuel pump housing

Number

Designation

Engine 256.9

BA07.02-P-1004-01MRT

Screw, support plate above fuel high-pressure pump to cylinder head

Nm

8

 High pressure fuel pump, high pressure fuel pump housing

Number

Designation

Engine 256.9

BA07.02-P-1006-01MRT

Screw, shield to fuel high-pressure pump housing/support plate

Nm

8

 Exhaust manifold

Number

Designation

Engine 256.9

BA14.10-P-1002-02MRT

Screw, exhaust manifold (exhaust gas turbocharger) strip clamp to cylinder head

Nm

20

 12 V on-board electrical system engine wiring harness

Number

Designation

Engine 256

BA15.18-P-1004-01MRT

Screw, electrical connector bracket to cylinder head

Nm

8

 Engine radiator, coolant hoses and lines

Number

Designation

Engine 256

BA20.20-P-1001-02MRT

Screw, coolant feed pipe to cylinder head/crankcase

Nm

8

Repair materials

Number

Designation

Order number

BR00.45-Z-1038-04A

Loctite 7200

Henkel AG & Co. KGaA
http://www.loctite.de

BR00.45-Z-1046-04A

Loctite 7063 (400 ml) cleaning spray

A 001 986 71 71 09