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How to remove a cylinder head

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Removing the cylinder head is straightforward on pushrod engines , but more complicated on overhead-camshaft ones because you have to disconnect the timing belt or chain.

Methods vary from one engine to another, so if possible consult a handbook for your make of car to verify all the details.

Buy a new head gasket and a new rocker-cover gasket. Make a sketch of all the connections to the head so that you can refit them correctly.

Disconnect the battery earth terminal and cylinder-head connections. Drain the coolant .

Leave the manifolds and carburettor attached if possible. If you do remove them, fit new gaskets (See Exhaust manifold gasket replacement ).

Removing a pushrod head

Unscrew the rocker-cover nuts or bolts; do not over tighten when refitting. The rocker cover may be fixed by nuts or bolts at the flange.

Undo the nuts or screws holding the rocker cover to the top of the head. Carefully lift off the cover.

If it sticks, tap the side gently with a soft-faced hammer. Set the cover upside-down on clean newspaper to catch oil drips.

You may need to loosen the rocker-shaft support pedestal nuts or bolts gradually in sequence, then remove them. Lift off the rocker shaft and put it on clean newspaper.

Lift out the pushrods one at a time. Number the pushrods so that you can refit them in their original places.

On engines with separately mounted rocker arms , take off the nuts holding the arms and the pivot balls, then remove the arms and set them all in a row on a piece of paper numbered with their correct order, so you can refit them in the same places.

Lift out the pushrods and stick them through numbered holes in a piece of cardboard or plastic foam; they too must go back in the same places. Keep them in a clean place.

Loosen and tighten the rocker shaft nuts or bolts in sequence.

Use a socket and bar to loosen the nuts or bolts securing the head in the reverse of the tightening sequence for the engine (see car handbook). Some engines need a special adaptor tool to fit the bolts.

Carefully lift off the head, complete with manifolds if possible. You may need a helper to lift the head. If it sticks, tap the side gently with a soft-faced hammer.

Every engine has a special sequence and torque setting for the head nuts or bolts.

Set the head right way up on wood blocks to protect its machined undersurface. Remove and discard the head gasket, after checking that the replacement one is the same in every detail.

Take care not to let any dirt or carbon particles fall into the engine while you are working on it.