Remove/Install Cylinder Head
Remove/install cylinder head
Shown On Model 220 With Engine 112, Part 1:
Shown On Model 220 With Engine 112, Part 2:
DANGER:
- Risk of explosion from hydrogen gas. Risk of poisoning and caustic burns from swallowing battery electrolyte. Risk of injury glasses to eyes and skin suffering caustic burns from battery electrolyte or from contact with damaged lead acid batteries.
- No fire, sparks, open flames or smoking. Wear acid-resistant gloves, clothing and glasses. Pour battery electrolyte only into suitable and appropriately marked containers.
1 Disconnect ground cable of battery.
NOTE:
- Turn key in electronic ignition switch EIS into position "0". Key cannot be withdrawn.
- Vehicle fitted with code (889) Keyless-Go: Switch off engine, remove Keyless-Go cards from the vehicle and store outside of transmitter range.
- Installation: After connecting, read out fault memory, set the time in the instrument cluster, code radio, normalize power windows and sliding/tilting roof and activate steering angle sensor.
- Vehicles with stationary heater: adjust time display on stationary heater.
2 Remove engine compartment paneling.
DANGER:
- Risk of injury to skin and eyes suffering scalding from contact with hot coolant spray. Risk of poisoning from swallowing coolant.
- Do not open cooling system unless coolant temperature is below 90 degrees C. Open cap slowly and release the pressure. Do not pour coolant into beverage bottles.
- Wear protective gloves, protective clothing and eye protection.
3 Drain coolant.
NOTE: At radiator.
4 Remove engine trim panel or cleaner
NOTE:
- Model 211, 215, 220, 230.475: Unclip cover on face end of engine.
- On model 220, 170.465, 230.475 the air cleaner is integrated in the engine trim panel. Remove engine cover or air cleaner by lifting vertically up and off the cylinder head covers.
5 Remove fan shroud (2) together with electric fan
NOTE: Before removing the fan shroud, separate the plug connection of the suction fan.
6 Attach guard plate for radiator/condenser.
- All except Model 230.474 /475.
7 Remove resonance pipe (5) together with resonance body (6)
- Separate plug connection of hot film mass air flow sensor (HFM-SFI) for this step and Unbolt resonance pipe at cylinder head cover.
NOTE:
- The resonance pipe is attached at the rear at the intake manifold with a plastic plate.
- DO not damage the plastic strap.
8 Remove hot film mass air flow sensor (HFM-SFI)
DANGER:
- Risk of explosion if ignition takes place, risk of poisoning caused by inhaling fuel vapors or swallowing fuel as well as risk of injury to skin and eyes exposed to fuel.
- Fire, sparks, open flames or smoking forbidden. Pour fuels only into suitable and appropriately marked containers. Wear protective clothing when handling fuel.
9 Disconnect fuel line at fuel rail.
NOTE: Release fuel pressure through service valve!
- Collect fuel!
10 Remove ignition coils (8,10).
11 Remove cylinder head covers (7, 9).
12 Remove poly V-belt of supercharger. Service and Repair
13.1 Remove compressor, install
13.2 Remove intake manifold (13). Service and Repair
NOTE:
- Remove intake manifold together with fuel rail.
- The intake manifold system must not be disassembled.
CAUTION: Installation: On vehicles with engine damage, the intake manifold must be examined for swarf before being installed and any swarf present must be removed, otherwise the next engine damage will be preprogrammed.
14 Remove camshaft position sensor (14)
NOTE: Only necessary if the right cylinder head is removed.
15 Unbolt dipstick guide tube from bracket at cylinder head.
16 Remove poly V-belt (3).
NOTE: Installation: Lock tensioning device with a drift or pin (diameter 5 mm).
17 Detach coolant line (15) at left cylinder head.
NOTE:
- On model 202.093/033 an additional coolant line is attached at the right cylinder head.
- The coolant line of the right cylinder head runs to an external transmission oil cooler which is located on the right behind the front molding.
18 Disconnect exhaust system from exhaust manifold.
CAUTION: Installation: On vehicles with engine damage, the exhaust system must be examined for swarf before being installed and any swarf present must be removed, otherwise damage will occur to the three way catalytic converter.
19 Position crankshaft to 40 degrees after ignition TDC of cylinder 1.
CAUTION: The engine must not be turned back; otherwise the timing chain can jump.
NOTE:
- Rotate engine at crankshaft in direction of rotation until 40 degrees marking on belt pulley/vibration damper is aligned with marking on timing case cover.
- The grooves on the camshafts must be pointing toward the inner V.
- If no valve timing index marks on the camshaft exist, the locating plate is used for adjusting valve timing.
20 Lock camshafts with locating plates.
21.1 Remove oil filter housing with oil-water heat exchanger (18).
21.2 Remove oil filter housing.
22 Remove chain tensioner (12). [1][2]Procedures
23 Unbolt camshaft sprockets (16).
NOTE:
- All except model 230.474/475. Right-hand camshaft sprocket:
- Tie timing chain tight on camshaft sprocket with cable strap.
- Left-hand camshaft sprocket: Mark camshaft sprocket to timing chain and remove camshaft sprocket.
- Model 230.474/ 475: Tie timing chain tight on both camshaft sprockets with cable straps.
- It is not possible for the timing chain to jump across at the crankshaft and balancing shaft.
CAUTION: If the camshaft sprockets are removed, the engine must no longer be cranked otherwise the timing chain might jam.
NOTE:
- After installing, Inspect basic position of camshafts.
- After inspecting, if necessary, Set the basic position of camshafts.
24 Remove camshaft bearing bridges (17)
25 Unscrew bolts (20) of cylinder head to timing case cover.
26 Take off locating plates and remove camshafts.
27 Slacken cylinder head bolts (21) in stages, unscrew.
CAUTION:
- Slacken cylinder head bolts on cooled off engine according to loosening pattern, otherwise the bolts would be over-tensioned.
- Installation: Observe tightening pattern and tightening instructions of cylinder head bolts.
- Oil thread and head contact surface of cylinder head bolts.
28 Remove cylinder head.
CAUTION:
- Installation: On Engine 113 it is necessary to apply sealing compound on the cylinder head gasket because of porous points in the left cylinder head, otherwise leakage could occur in the left cylinder bank.
- Information on applying sealant to cylinder head gasket.
- Loctite 5900 sealant.
NOTE:
- The sealant must be applied within 10 minutes.
- See Information on cylinder head contact surface.
29 Inspect version of cylinder head gasket
- See Assignment of cylinder head gasket
30 Check cylinder head bolts (21)
31 Clean sealing surfaces, inspect for cracks, shrink holes and flatness, clean threaded holes.
NOTE:
- Sealing surfaces of crankcase and cylinder head are provided with an 0.8 mm thick silicone layer during series production. Silicone sealant is applied in the gasket area when carrying out repairs only if shrink holes are present.
- The sealant must be applied within 10 minutes.
CAUTION: Observe fitted sleeves (26) for fixing of cylinder head, otherwise it may lead to a jamming of the cylinder head.
32 Install in the reverse order
DANGER:
- Risk of accident. Accidents may result if the vehicle starts off unintentionally with the engine running. Risk of injury as working around the engine during start-up or while running may result in contusions and burns.
- Secure vehicle to prevent it from moving. Wear closed and snug-fitting work clothes. Do not grasp hot or rotating parts.
33 Run engine and inspect for leaks.
34 Inspect cooling system for leaks
NOTE: Warm up engine to operating temperature and then inspect cooling system for leaks.
35.1 Read diagnostic trouble code memory and erase
NOTE: Stored faults which can result from cables being disconnected or from simulation during removal and installation or test work, have to be processed and erased in the fault memories after completing the work.
35.2 Read diagnostic trouble code memory and erase.