R CYLINDER HEAD - OVERHAUL

Operation 1016E22 · CYLINDER HEAD/S - VARIOUS OPERATIONS

3.0 24V V6

Dismantling

1. Fit the cylinder head support tool (1a) tightening the fixing nuts (1b).

2. Position the cylinder head in the vice.

1. Rotate the camshaft pullies so that the opening (1a) in the actual pulley is aligned with the opening (1b) in the head; insert the retaining/timing pins (1c) through the openings.

2. Undo the bolt (2a) fixing the exhaust camshaft pulley (2b), then remove it from the cylinder head.

3. Undo the bolt (3a) fixing the inlet side camshaft pulley (3b), then remove it from the cylinder head.

1. Undo the bolts (1a) fixing the timing drive belt rear guard (1b), then remove it from the cylinder head.

1. Undo the bolts (1a) and remove the inlet and exhaust side camshaft bearing caps (1b) single covers.

Gradually loosen the bolts in a spiral formation fixing the camshaft single covers starting from the outside.

2. Remove the camshafts.

3. Remove the camshaft front oil seals.

4. Remove the hydraulic tappets.

1. Remove the cotters (1a) using the tools (1b), (1c), (1d), (1e) and (1f).

2. Remove the upper valve shim.

3. Remove the valve spring.

- Remove the tools used for dismantling the valves.

4. Remove the valve.

- Carry out the same operations for removing the remaining valves.

1. Remove the valve guide oil seal (1a) using the tool (1b).

1.870.894.000, Valve guide oil seal extraction2. Remove the lower valve shim.

- Remove the cylinder head from the support tools and place it on a special workbench.

- Turn the cylinder head upsidedown on the workbench.

1. Remove the valve guides (1a) using the tool (1b).

Reassembly

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

- Clean any residues of sealant from the upper cylinder head planes without using cutting tools that can damage the surface of the head.

1. Check that the flatness of the lower cylinder head plane corresponds to the recommended values.

1. If the planarity of the lower cylinder head plane does not correspond to the recommended figures, regrind it without exceeding the minimum permitted height.

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

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

- Check that the thickness of the cylindrical section of the valve head is within the recommended values.

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

- Check that the diameter of the hydraulic tappet housings corresponds to the recommended figures; if not, replace the cylinder head.

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

- Using a torque wrench, check that the spring specifications correspond to the recommended figures; if not, replace the components that do not comply.

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

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

1. Fit the single covers with the function of camshaft caps and tighten the fixing bolts following the procedure described below and bearing in mind that the order for each tightening stage is the one illustrated in the diagram.

- Pre-tighten the tappet cover fixing bolts to the value given in the table.

- Tighten the tappet cover head cover fixing bolts definitively to the recommended torque.

1. Check that the diameter of the camshaft supports corresponds to the recommended figures; if not, replace the cylinder head.

- Measure the valve guide bore and check that it is within the recommended values.

- If necessary, ream the valve seat.

- Check the measurement of the new valve guide.

- Check the measurement of the new valve guide. - Make a note of the measurement of the valve seat after reaming.

- Valve guides are available as spares with the following diameters.

- The interference between the valve guides and the seats in the cylinder head is as follows.

- Before fitting the new valve guides the cylinder head must be heated to a temperature of around 80° - 100 °C.

1. Fit the new valve guides (1a) using the tool (1b).

- If the valve guides have become slightly distorted during fitting, ream the inner surface using a suitable sized diameter reamer.

- Measure the valve guide inner diameter after refacing and the clearance with the valve; check that it is within the recommended values.

- Grind the valve seats if the valves and the valve guides are being replaced.

- When the operation is completed, clean the valve seats thoroughly.

- Fit the cylinder head on the support tools and fasten it using the nuts.

- Fit the valve spring lower plate.

- Fit the valve spring lower plate.1. Place the oil seal on the valve guides (1a) positioning the drift (1b) on the valve stem temporarily inserted in its housing.

2. Fit the oil seal in its housing using the special drift.

1. Fit the valves (1a) for the cylinder in question and support it using the tools (1b) and (1c).

2. Fit the valve spring.

3. Fit the upper valve shims.

4. Fit the cotters (4a) using the tools (4b), (4c), and (4d).

- Carry out the same operations to refit the remaining valves.

- Remove the tools used for fitting the valves.

1. Fit the hydraulic tappets.

Before refitting the components removed, lubricate them with engine oil. Make sure that the tappets are refitted in the original housings, then check that the tappets rotate freely in the head.

2. Fit the camshafts.

3. Check that the centering pins for the camshaft cover single covers are present.

4. Apply a bead of sealant continuously to the contact surface with the camshaft single covers.

5. Position the camshaft cap single covers (5a) using the fixing bolts (5b).

1. Tighten the bolts fixing the camshaft cap single covers, following the procedure described below and following the tightening order illustrated in the diagram for each stage (different for the left and right sides).

When positioning the camshaft covers, avoid extensive horizontal movements that could remove sealant.

- Pre-tighten the bolts fixing the single covers with a camshaft cam function to the value given in the table.

- Tighten the bolts fixing the single covers with a camshaft cap function to the recommended torque.

1. Fit the camshaft front oil seals (1a) using the tool (1b).

- Fit the timing belt rear guard and secure it using the bolts.

1. Position the inlet side camshaft pulley (1a) inserting the centering pin (1b), in the pulley, in the splining (1c) in the camshaft; bear in mind that the pulley should be fitted with the reference (1d) facing the outside of the engine.

2. Screw in the bolt fixing the inlet side pulley to the camshaft without tightening it.

3. Position the exhaust side camshaft pulley (3a) inserting the centering key (3b), in the pulley, in the splining (3c) in the camshaft; bear in mind that the pulley should be fitted with the reference (3d) facing the inside of the engine.

4. Screw in the bolt fixing the exhaust side pulley to the camshaft without tightening it.

1. Rotate the camshaft pullies so that the opening (1a) in the actual pulley is aligned with the opening in the head; insert the retaining/timing pins (1b) through the openings.

2. Tighten the bolts (2a) fixing the inlet and exhaust side camshaft pullies to torque using the special angular tightening tool (2b).

3. Tighten the plugs for the inlet and exhaust side camshaft pulley.

- Undo the fixing nuts and remove the cylinder head support.