Refitting

CAMSHAFT HOUSING

1. Position the camshaft housing (1a) in a vice using the tool (1b).

1. Undo the screws (1a) and remove the engine oil filler (1b).

- Remove the gasket.

2. Undo the screws (2a) and remove the vacuum unit (2b).

- Remove the gasket.

1. Undo the bolt (1a) and remove the cam angle sensor (1b).

1. Remove the plugs (1a) and fit the camshaft timing tools (1b) on the camshaft housing.

Check that the tools are correctly fitted in the housings in the camshafts.

1. Undo the bolts securing the camshaft gears.

1. Undo the bolt (1a) and remove the exhaust side camshaft toothed drive pulley (1b).

- Remove the camshaft timing tools from the camshaft housing.

1. Withdraw the camshafts (1a) as far as necessary and remove the camshaft gears (1b).

1. Using a suitable drift, extract the inlet side camshaft (1a) and the plug (1b).

2. Using a suitable drift, extract the exhaust side camshaft (2a) and the oil seal (2b).

1. Undo and remove the engine oil lubrication duct plugs.

1. Position the cylinder head (1a) in a vice using the tool (1b).

2. Remove the tappet assemblies.

1. Unscrew and remove the heater plugs using the tool.

1. Open the bands (1a), disconnect the pressure signal pipes (1b) and remove the differential pressure sensor (1c) complete with bracket and hoses.

1. Undo the air chamber fixing screws (1a) and the EGR valve fixing screws (1b) and remove the exhaust gas supply pipe to the air chamber (1c) complete with O-ring and gasket.

1. Undo the screws (1a) and remove the throttle body (1b).

1. Undo the fixing screws (1a) and nuts (1b) and remove the thermostat/EGR valve/EGR heat exchanger assembly (1c).

1. Remove the thermostat/EGR valve/EGR heat exchanger assembly gasket.

1. Undo the fixing nuts (1a) and remove the air chamber (1b).

1. Undo the screws (1a) and remove the water pump return connector (1b).

1. Undo the bolts (1a) and remove the water pump (1b).

2. Open the retaining tabs and remove the gasket.

1. Fit a wooden stand on the cylinder head surface to support the valves, and secure it using suitable bolts.

1. Remove half-cones (1a) using tools (1b) and (1c).

2. Remove the valve upper shim.

3. Remove the valve spring.

4. Remove the shim (for exhaust valves only).

5. Remove the valve guide oil seal ring with built-in lower valve shim.

- Carry out the same operations on the other valves.

- Remove the wooden stand and keep the valves.

- Remove the lower cylinder head from the support tool.

- Replace the valve guides

    Op. 1016E14 VALVE GUIDES FOR SINGLE CYLINDER HEAD - REPLACE DURING OP.1016E10

Removing

- Clean any residues from the old gasket from the lower cylinder head plane.

- Check that the flatness of the lower cylinder head lower plane corresponds to the prescribed values with reference to

   Op. 1016E38 SINGLE CYLINDER HEAD OR (ONE) LEFT OR RIGHT, REMOVED - GRINDING

- Check that the valves do not show signs of grooves or meshing.

- Check that the diameter of the valve stems corresponds to the recommended figures; if not, replace the worn valves.

- Check that the length of the valve springs released is within the prescribed values.

- Using a torque wrench, check that the valve spring specifications correspond to the prescribed figures; if not, replace the worn components.

- Check that the diameter of the camshaft journals corresponds to the recommended figures; if not, replace the worn camshaft.

- Check that the nominal camshaft cam lift corresponds to the recommended figures; if not, replace the worn camshaft.

1. Check that the diameter of the camshaft supports corresponds to the prescribed figures; if not, replace the upper camshaft housing.

- The outer diameter of the valve housings is as follows.

1. Grind the valve seats to the prescribed size.

- Grind the valve seats using a suitable tool.

LOWER CYLINDER HEAD

- Position the lower cylinder head in the vice using the tool.

- Fit the valves in the seats, then support them using the wooden stand and secure it using suitable bolts.

1. Place the valve guide oil seal (1a) in position using the tool (1b).

- Place the shim in position (for exhaust valves only).

- Fit the valve spring in its seat.

- Refit the upper valve shim.

- Place the cotters in their seats with the lever and chamber used for the removal.

- Carry out the same operations on the other valves.

- Remove the wooden stand for supporting the valves from the cylinder head plane.

- Place a new gasket on the water pump and fold the retaining tabs over.

- Refit the water pump, complete with gasket, in its housing and secure it by tightening the screws to the prescribed torque.

- Place the water pump return connector, complete with new gasket, in position and tighten the screws to the prescribed torque.

1. Replace the air chamber (1a) in its housing and tighten the nuts (1b) to the prescribed torque.

1. Place the thermostat/EGR valve/EGR heat exchanger assembly (1a) complete with new gasket in its housing and tighten the fixing screws (1b) and nuts (1c) to the prescribed torque.

1. Place the throttle body (1a) in its housing and tighten the screws (1b) to the prescribed torque.

- Place the air chamber exhaust gas supply pipe in position complete with new O-ring and tighten the screws.

Before fitting the pipe, bathe the rubber gasket in soapy water and tighten all the fixing screws before their definitive tightening.

- Refit the differential pressure sensor complete with bracket and hoses, connect them and close the bands.

1. Refit the heater plugs in their housing using the tool and tighten them to the prescribed torque.

- Place the hydraulic tappets complete with rocker arms in their housings.

- Remove the lower cylinder head from the support tool.

CAMSHAFT HOUSING

1. Position the camshaft housing (1a) in a vice using the tool (1b).

- Tighten the engine oil lubrication duct plugs.

- Place the camshafts in their housings.

- Refit the camshaft gears in their housings and secure them without tightening the bolts.

1. Fit the camshaft timing tools.

Check that the tools are correctly fitted in the housings in the camshafts.

1. Tighten the camshaft gear bolts to the prescribed torque.

1. Fit the exhaust side camshaft front oil seal (1a) using the tool (1b).

- Fit the inlet side camshaft plug.

- Place the exhaust side camshaft toothed drive pulley in its housing and secure it without tightening the bolt.

1. Position the cam angle sensor (1a) in its housing and secure it by tightening the screw (1b) to the prescribed torque.

1. Fit the vacuum pump (1a), complete with gasket (1b), back in its housing and secure it by tightening the screws (1c) to the prescribed torque.

2. Place the engine oil filler fitting (2a) in its housing complete with gasket and secure it by tightening the screws (2b) to the prescribed torque.

- Remove the support tool complete with camshaft housing from the vice and separate them.