Cylinder head — cleaning and inspection (BMW 7 Series E32)

If the engine has been overheating significantly, the cylinder head may have become warped.

Clean all traces of sealant and old gaskets from the surface of the cylinder head that contacts the cylinder block, exhaust and intake manifolds. Do not scratch the surface! Use solvent.

Clean out any deposits in the coolant passages.

Clean all holes with a stiff wire brush to remove any deposits that may have built up.

Run a tap of the appropriate size through all threaded holes to remove all traces of corrosion and sealant. If you have a compressor, use compressed air to clean all holes from small particles formed during this operation.

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

Clean the cylinder head with solvent and dry it thoroughly.

Clean rocker arms, axles, nuts and bolts with solvent (without confusing them) and dry thoroughly.

Clean the valve springs with solvent and dry them thoroughly. Work on only 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 drill with a wire brush or sandpaper to clean the deposits off the valve heads and stems. Make sure the valves are not reversed.