Disassembly And Assembly: Overhaul: Disassembly
- Remove the cylinder head. Refer to CYLINDER HEAD, REMOVAL AND INSTALLATION
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- Install the Cylinder Head Overhaul Support 1860470000 (1b) to the turbocharger mounting studs on the cylinder head (1a).
- Remove the bolts (1a) and the thermostat (1b) with O-ring.
- Remove the bolt (1a) and the camshaft position (CMP) sensor heat shield (1b).
- Remove the CMP sensor (2).
- Remove the Multiair actuator oil supply filter (1).
- Remove the bolts (1a) and remove the high pressure fuel pump (1b).
- Install the 2032400091 valve retaining tool (1).
- Compress the valve springs using 1860790000, 2000026800 (1a), 1860788000 (1b) and remove the valve spring retainer locks (1c).
- Remove the valve spring retainers (1).
- Remove the valve springs (2).
- Use the 1870894000 tool (1a) to remove the valve guide seals (2b) from the valve guides.
- Remove the tools from the cylinder head.
- Remove the intake and exhaust valves.
- Remove deposits and clean the valve seats and ports.
- Clean any gasket residue from the lower cylinder head surface.
- Check the flatness of the cylinder head surface. Refer to SPECIFICATIONS .
- If necessary, refinish the lower cylinder head surface; 0.1 mm of material can be removed from the minimum cylinder head height. Refer to SPECIFICATIONS
.
- Check that the resurfacing has not changed any of the combustion chambers in the areas shown in the figure (1); otherwise the cylinder head must be replaced.
- Also check all the combustion chamber volumes as described below:
- Temporarily install the valves and spark plugs. Fill a graduated burette (1) with a known amount of engine oil.
- Rest a glass plate (2) on the cylinder head with holes corresponding to the combustion chambers.
- Fill the combustion chamber completely (3), taking care not to pour oil outside of the combustion chamber.
- Wait about 10 minutes to allow the oil to settle.
- Measure the amount of oil remaining in the burette and then calculate the difference between this and the amount of oil used initially with the burette full. The difference is the volume of the combustion chamber.
- Check that this value is within the specified values; if it is not, replace the cylinder head. Refer to SPECIFICATIONS .
- Check that the valve stem does not show signs of grooves or seizing.
- Check that the diameter of the valve stems is within the specified values; if not, replace the worn valves. Refer to SPECIFICATIONS .
- Check that the diameter of the valve head is within the specified values; if not, replace the valves. Refer to SPECIFICATIONS .
- Check that the inner diameter of the valve guide and the clearance between it and the valve are within the specified values, otherwise replace the valve guide. Refer to SPECIFICATIONS .
- If required, replace the valve guides
Refer to VALVE GUIDES, REMOVAL AND INSTALLATION .
- Using a suitable tool, check that the valve springs are within specifications; if not, replace the worn springs. Refer to SPECIFICATIONS .