Cylinder Head Cleaning

Cleaning

PROCEDURE

1. Thoroughly clean the cylinder head and valve train components, then inspect them in detail. This will help determine the approximate scope of the required repair work.

Severe engine overheating can cause cylinder head distortion and loss of flatness of its mating surfaces.
2. Scrape all traces of old gasket material and sealant from the mating surfaces of the cylinder head, intake manifold and exhaust manifold. Be careful not to damage the surfaces. Using a special softener, applied first to soak the stuck deposits, will greatly simplify this work.
3. Remove all scale deposits from the walls of the coolant passages.
4. Thoroughly clean all accessible cavities and holes with a stiff wire brush. If the passages are heavily contaminated, have the cylinder head cleaned by a specialist.
5. Chase each bolt hole with a tap of suitable size, removing corrosion products, old sealant and restoring damaged threads. If compressed air is available, blow out the holes to remove chips and fine debris.

When using compressed air, always wear safety glasses!
6. Clean the threads of the studs for the intake manifold and exhaust manifold with a wire brush.
7. Wash the cylinder head with solvent and dry it thoroughly. Using compressed air will significantly reduce drying time and ensure that hard-to-reach cavities and holes are properly cleaned.

Various carbon removal compounds, which greatly simplify cleaning, are available at many auto accessory stores. Remember that these products are usually chemically aggressive and must be used with appropriate precautions. Strictly follow the manufacturer's instructions, usually printed on the container label.
8. Wash the rocker arms with solvent, then dry them thoroughly. Using compressed air will make this easier (wear safety glasses).

On VTEC-equipped models, secure the intake valve rocker arms together with rubber bands.
9. Wash the valve springs, spring retainers and split keepers in solvent and dry them thoroughly. Take care not to mix up the components.
10. Scrape off the bulk of the deposits from the valves, then use a wire brush attachment on an electric drill to finish cleaning the valve stems and heads. Make sure the valves do not get mixed up.
11. Remove and thoroughly clean the hydraulic lash adjusters/valve lash adjusters (VTEC). Arrange the removed components in an organized order.

The oil spray jet(s) must be removed and thoroughly cleaned at this stage. On 4-cylinder engines, the jets are located in the upper part of the cylinder head; on V6 engines, they are located in the cylinder block (under the cylinder head).