Remove/install cylinder head

AR01.30-P-5800MT

Remove/install cylinder head

26.08.2020

Engine

270 in model 117, 156, 176, 242, 246.2

Modification notes

12.08.2020

Note deleted.

Operation step 14.

26.08.2020

Seal openings using lint-free rags or suitable protective covers.

Operation step 10.

1

Cylinder head cover

2a

Camshaft

2e

Camshaft

4

Compensating element

5a

Camshaft bearing bridge

5b

Camshaft bearing bridge

6

Cylinder head bolt

7

Cylinder head

8a

Slide rail pins

8b

Slide rail pins

9

Cylinder head seal

11

Crankcase

12s

Bolts

13s

Screw

16

Coolant line

13

Charge air pipe

15

Turbocharger

16s

Screw

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 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

 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

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

Topical note

Notes on coolant

AH20.00-N-2080-01A

 

Remove/install

1

Remove gas distribution rail.

Engine 270 in model 242
with code 924 (Bivalent natural gas drive)

AR07.03-P-0001NKB

2

Disconnect ground line from battery.

AR54.10-P-0003NKB

3

Remove the cylinder head cover (1).

AR01.20-P-5014MT

4

Remove all detachable parts and lines from the exhaust gas turbocharger (15).

AR09.40-P-6025MT

 All operation steps in the reference document must be carried out, but the exhaust gas turbocharger (15) remains on the cylinder head (7).

5

Remove screws (12s).

6

Unscrew screw (16s) for the coolant line (16).

7

Remove screw (13s).

8

Remove charge air hose from charge air pipe (13) and seal openings with suitable protective covers.

AR09.41-P-1311-01AL

 Set of protective covers

*001589019100

9

Remove charge-air distributor from the cylinder head (7) and place to one side with attached throttle valve actuator and charge air pipe (13).

AR09.41-P-1310MT

10

Seal openings using lint-free rags or suitable protective covers.

 Set of protective covers

*001589019100

11

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

12

Remove camshafts (2a, 2e).

AR05.20-P-6992MT

13

Remove camshaft bearing bridges (5a, 5b).

General information on checking camshafts and bearing points of camshafts

AH05.20-P-1000-09SZ

14

Remove slide rail pins (8a, 8b).

 Installation: The threads of the slide rail pins (8a,  8b) must point outwards.

 Puller

*270589013300

 Puller

*605589003300

15

Remove spark plugs.



AP15.10-P-1580NK

16

Loosen cylinder head bolts (6) in stages in the reverse order of the tightening procedure and remove.

AR01.30-P-5800-01MT


Only loosen the cylinder head bolts (6) for a cooled off engine.
Otherwise, damage to the cylinder head (7) will occur.

 Installation: Replace cylinder head bolts (6).

 Bolt, cylinder head to crankcase

*BA01.30-P-1001-01Y

 Bolt, cylinder head to timing case cover

*BA01.30-P-1002-01Y

17

Remove cylinder head (7) from crankcase (11).

General information on checking valves, valve seats and valve guides

AH05.30-P-1000-02SZ

 Installation: Pay attention to the pilot bushing of the cylinder head (7).

18

Remove cylinder head gasket (9) from crankcase (11).

19

Remove compensating elements (4).

When replacing cylinder head (7).

AR05.00-P-2011MT

20

Remove coolant temperature sensor (B11/4).

When replacing cylinder head (7).

AR15.60-P-2711MT

21

Remove exhaust gas turbocharger (15) with exhaust manifold.

When replacing cylinder head (7).

AR09.40-P-6025MT

22

Remove valves.

When replacing cylinder head (7).

AR05.30-P-3511MT

23

Remove valve stem seals.

When replacing cylinder head (7).

AR05.30-P-3500MT



Clean

24

Clean sealing surfaces on the cylinder head (7), timing case cover, and crankcase (11).

AR01.00-P-0050-01A


Do not use any sharp-edged tools or abrasive paper.
The sealing surfaces can be damaged otherwise.

Loctite 7200

*BR00.45-Z-1038-04A

Loctite 7063 (400 ml) cleaning spray

*BR00.45-Z-1046-04A

25

Blow out threaded holes of the cylinder head bolts (6) in the crankcase (11) with compressed air and clean off engine oil and coolant.

26

Check sealing surfaces on the cylinder head (7), timing case cover, and crankcase (11) for cracks, unevenness, and other damage.


The cylinder head (7) and crankcase (11) may not be reworked (surface grinding).
The permissible machining tolerances will be exceeded otherwise.

 Any distortion of cylinder head (7) in the longitudinal or transverse direction will be balanced out again during assembly through tightening of cylinder head bolts (6).

If cracks, unevenness, or other damage are present,



replace cylinder head (7), timing case cover, and crankcase (11).

Timing case cover

AR01.40-P-8000MT

Crankcase

AR01.10-P-2401MT

27

Install in the reverse order.

28

Change engine oil and oil filter element.



Engine 270.910 in model 117, 156, 176, 246.2

AP18.00-P-0101NK



Engine 270.920 in model 117, 156, 176, 242, 246.2

AP18.00-P-0101NL

 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

29

Check leak tightness of natural gas system with the engine running.

Engine 270 in model 242
with code 924 (Bivalent natural gas drive)

AR07.54-P-0001NKB

 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

30

Perform engine test run and check engine and fuel system for leak tightness.

 Cylinder head

Number

Designation

Engine 270

BA01.30-P-1001-01Y

Bolt, cylinder head to crankcase

M11

Stage 1

Nm

10

Stage 2

Nm

40

Stage 3

°

90

Stage 4

°

90

Stage 5

°

90

 Cylinder head

Number

Designation

Engine 270

BA01.30-P-1002-01Y

Bolt, cylinder head to timing case cover

M8

Nm

20

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