Cylinder head — assembly (Opel Astra F)

After cleaning, install the valve parts as required.

Insert the appropriate valve into its guide (if new valves are being installed, insert each one into the specific position in which it was ground), making sure that the valve stem is well lubricated with clean engine oil. If these are old parts, they must be put back in their original position.



Install the valve seat.



New valve stem seals should come with a bushing that fits over the keeper groove in the valve stem to prevent damage to the seal. If there is no bushing, wrap a short piece of tape around the top of the valve stem to cover the keeper groove.

Lubricate the valve stem seal with clean engine oil, then pull the seal down the valve stem using a suitable tube or ring until the seal is fully seated on the spring seat. Remove the installed sleeve or band from the valve stem.



Install the valve spring and spring retainer.

Install the spring compressor, compress the valve spring until the spring retainer passes the cracker groove in the valve stem.

Apply a small amount of grease to the keeper groove, then install the keeper into the groove with the narrow ends closest to the spring. The grease should hold them in the groove.

Slowly release the spring compressor, making sure the spring keepers are not displaced in the groove. Once the mechanism is fully released, lightly tap the top of the valve assembly with a soft hammer to fully seat the parts.

Do the same with the remaining valves (checking, if old parts are used, that they are put back in their original position).

On twin cam engines, install the hydraulic valve lifters into the cylinder head in their original position. Lubricate the bores generously with oil, and if new lifters are being installed, first soak them in a container of clean engine oil and squeeze each one (by hand) several times to fill them.

Install the following components where required:

• a) On twin cam engines, install the camshafts.
• c) Install the thermostat housing (together with the thermostat on 1.4 and 1.6 l engines), using a new seal where required (chapter 3).
• c) Install the spark plugs (chapter 5).
• d) Install the collectors (chapter 4).