Cylinder head — cleaning and checking

If the engine has been overheated, the cylinder head may have become deformed.

Clean all traces of sealant and old gaskets from the surface of the cylinder head in contact with the cylinder block, exhaust and intake manifolds. Don't scratch the surface! Use a solvent.

Clean off any deposits in the coolant passages.

Clean all openings with a stiff wire brush to remove deposits that have formed there.

Run an appropriately sized tap through all threaded holes to remove all traces of corrosion and sealant. If there is a compressor, clean all holes with compressed air from small particles formed during this operation.

Clean the threads of the bolts, hinges, rocker arms with a wire brush.

Clean the cylinder head with solvent and dry thoroughly.

Solvent clean the rocker arms, axles, nuts and bolts (without confusing them) and dry thoroughly.

Clean the valve springs with solvent and dry thoroughly. Only work on parts for one valve at a time to avoid mixing them up.

Scrape off any hard deposits that may have formed on the valves, then use a wire brush drill or sandpaper to clean the deposits off the valve heads and stems. Make sure the valves are not reversed.