If your car's radio is equipped with an anti-theft system, make sure you have entered the correct code before disconnecting the battery.
If, after connecting the battery, the inscriptions on the instrument panel appear in the wrong language, refer to Section Anti-theft audio system and instrument panel language, for instructions on how to set the desired language.
Withdrawal
1. Disconnect the negative battery cable.
2. Disconnect the breather hose from the cylinder head cover.
3. On M20 engines, unbolt and remove the intake manifold support bracket and, if available, the bracket for engine sensors or idle speed stabilizer (it will probably be necessary to disconnect the electrical connectors of the sensors and the stabilizer).
4. On M30 engines, disconnect the electrical connector for the airflow meter. Remove the clamps from the electrical wiring and take it to the side.
5. Where necessary on M30 engines, disconnect the hoses and fittings from the air intake hose, then release the clamp and remove the hose from the throttle body. Give nuts of fastening of a casing of an air cleaner and remove a casing together with a hose and a measuring instrument of an air stream.
6. Give fixing nuts and washers of a cover of a head of cylinders.
Location of cylinder head cover bolts (indicated by arrows) on four-cylinder M10 engines.
Location of cylinder head cover bolts (indicated by arrows) on six-cylinder M20 engines.
7. Where necessary, disconnect the spark plug wire clip or cap from the gap adjustment screw and set it aside. There is usually no need to disconnect the spark plug wires.
8. Remove the cylinder head cover and gasket. Throw away the old gasket. On M40 engines, also remove the camshaft cover.
9. Remove the cylinder head cover from the M40 engine.
10. Remove the camshaft cover from the M40 engine.
11. Remove the cylinder head cover gasket from the M40 engine.
12. If provided, remove the semicircular seal from the valve on the front of the cylinder head.
Installation
1. Using a scraper, remove all traces of the old gasket material from the surfaces of the cover and cylinder head.
Be extremely careful not to damage the soft aluminum surfaces. There are commercially available, and may be useful, special solvents for removing gaskets. Once the gasket material has been completely removed, the gasket surfaces can be cleaned of grease using a cloth soaked in a suitable solvent.
2. If provided, install a semi-circular seal on the valve at the front of the cylinder head, then apply RTV Gasket Sealant to the joints between the seal and the corresponding cylinder head cover gasket surface.
After applying the sealant, install the cylinder head cover and tighten the nuts within ten minutes or less.
3. Install the camshaft cover (M40 engines), cylinder head cover and a new gasket. Fit washers and nuts; tighten the nuts securely and evenly. Do not overtighten them - they should be tight enough to prevent oil from leaking through the gasket, but not too tight so as not to deform the cover.
4. The rest of the installation procedure corresponds to the removal in reverse order.