4.7.6. Cleaning and check of a condition of a head of cylinders

Careful cleaning of a head of cylinders and components of the valvate mechanism with the subsequent detailed check of their state will help to determine the approximate volume of the forthcoming recovery work.

Strong overheats of the engine can lead to deformation of a head of cylinders and violation of planeness of its interfaced surfaces.



  1. Scratch out from the interfaced surfaces of a head of cylinders, all traces of material of old laying and sealant, - try not to damage surfaces.

Application of a special razmyagchitel which should impregnate previously stuck deposits will significantly facilitate work, - ask in shops of automobile accessories.

  1. Remove all traces of a scum from walls of water channels.
  2. Rigid wire brush carefully clean all available cavities and openings. At strong pollution of canals the clearing of a head should be charged to experts.
  3. "Banish" the tap suitable by the size each of bolted openings, having removed corrosion products, traces of old sealant from a carving and having restored the damaged rounds. In the presence of access to a source of compressed air, blow openings, having removed from them shaving and small garbage.

When using compressed air do not forget to put on goggles!

  1. By means of solvent and a brass wire brush clear combustion chambers of a deposit.
  2. Wash out a head solvent and carefully dry it. Use of compressed air will allow to reduce significantly the term of drying and will give a quality assurance of a clearing of badly available cavities and openings.

Different structures for removal of traces of a deposit significantly facilitating implementation of the procedure of cleaning can be got in many shops of automobile accessories. Remember that such means usually are chemically aggressive and have to be applied with observance of the appropriate measures of precaution, - strictly adhere to instructions of the manufacturers who are usually given on the label of a container.

  1. On SOHC engines wash out solvent levers of the drive of valves. Carefully dry components with use of compressed air and put them in an organized order.
  2. Wash out solvent and dry pushers / hydraulic compensators of valvate gaps.

Use of compressed air will significantly facilitate implementation of the procedure (do not forget to put on goggles).

  1. Wash out in solvent and carefully dry valvate springs, their plates and crackers of cutting locks, - try not to mix components.
  2. Scratch out the bulk of the valves of deposits created on surfaces, then a wire nozzle to the electric drill finally smooth out surfaces of cores and plates of valves - you watch that valves were not mixed.

Check of a state

Before making the decision on need of carrying out machining of a head of cylinders, carefully study its state. Having got acquainted with the material stated in the real subsection, make the list of the components needing special attention.

Head of cylinders


  1. Attentively check a head of cylinders for existence of traces of leak of cooling liquid, cracks and other damages. The burst head is subject to replacement without fail. In case of lack of confidence in definition of a condition of a head, it is necessary to send it for check to a workshop of car service. If repair is not possible, replace a defective head.
  2. By means of the measuring instrument of planeness and the probe of lezviyny type check the interfaced head surface for existence of signs of deformation. If not planeness exceeds value, admissible on standards (see Specifications in the Head Dvigateli), the head needs to be sent to a pro-point in a mechanical workshop.

One of working parameters of heads of cylinders is their minimum admissible height (II) (from the interfaced surface to the interfaced surface) which should not be belittled in the course of machining (see Specifications in the Head Dvigateli).

  1. The core of the valve should not act from a head of cylinders at a size more "I" For l OHC 1.2 and 1.4 engines this size has to be no more than 14.4 mm. The valve end face is not subject to processing. If the I size is exceeded, the head of cylinders should be replaced.
Assessment of extent of deformation of a head of cylinders is made on diagonals of each of the interfaced surfaces
Measurement of height of a head of cylinders is performed from the interfaced surface to the interfaced surface
Measurement of height of a ledge of the valve over a head of cylinders
  1. Check a condition of saddles of valves in each of combustion chambers. In case of identification of cavities, cracks, traces of a progar, the head should be subjected to special recovery repair which performance lies outside qualification of the average amateur mechanic and it has to be entrusted to specialists of car service (worn-out guides of the plug of valves have to be replaced previously).

On diesel engines there is a possibility of replacement of saddles of valves.

  1. By means of a special nutromer measure the internal diameter of the directing valve plug. After extraction of the measuring instrument from the plug measurement is made by its micrometer. Measure also outer diameter of a core of the valve. For the purpose of determination of size of a gap of landing of the valve in the plug subtract result of the second from result of the first measurement. Compare the obtained data with requirements of Specifications in the head Dvigateli.

When using of a nutromer enter it to the middle of length of the plug, then move up-down. Unevenness of resistance to movement of the measuring instrument demonstrates existence of conicity of the plug. In the absence of confidence when determining a condition of components do not hesitate to ask for the help experts.

  1. Worn-out plugs are subject to replacement. Old plugs are beaten out in combustion chambers by means of a drift. Before installation new plugs should be cooled in the freezer, then to press in drillings of a head from the camshaft to ordered by norms (see Specifications in the Head Dvigateli) vystupaniye level (if the vystupaniye of the directing plug given on height are not given, address for consultations specialists of company car repair shop of the Opel company).

Sign of weakening of landing of valves in the directing plugs is emergence of blue smoke at the exit of system of production of the fulfilled gases.

  1. On diesel engines check for existence of cracks and progar forkamer. Insignificant defects should not cause concerns. Replacement of cameras is required only in cases of deep progar, losses of an initial form or weakening of landing in casting of a head. In the absence of confidence in definition of a state a forkamer do not hesitate to ask for the help experts.



  1. Attentively check the working surfaces of valves for existence of signs of uneven wear, deformations, cracks, cavities and traces of a progar. Estimate extent of operation of cores of valves. Check whether there are no cracks in necks of cores. By rotation check valves for a bend. Make sure of lack of cavities and signs of excessive wear of end faces Identification of any of the listed defects demands delivery of valves for recovery repair in a workshop of car service.

The sites of valves which are subject to check
1 — End faces (shafts) of cores
2 — Flutes under installation of crackers of cutting locks of plates
3 — Cores
4 — Working facets
5 — the Final valve
6 — the Cylindrical part of a plate (corbel)
7 — the Inlet valve

  1. Measure width of a cylindrical part (corbel) of a plate of each of valves. If width of a corbel appears less than the value stipulated in Specifications in the Head Dvigateli, replace the valve.

Width of a cylindrical part (corbel) of a plate of the valve has to be not lower than the value stipulated in Specifications

Valvate springs


  1. Estimate degree of wear of face parts of each of valvate springs, check springs for existence of cavities. By means of the angular measuring instrument determine free length and check a tortsovka of valvate springs. Compare results of measurements to requirements of Specifications in the Head Dvigateli, - if the spring is shorter than the lower admissible limit, it is sunk and is subject to replacement. Check also for compliance to standard requirements the efforts developed by springs (better to charge performance of this work to experts of a workshop of car service). In the absence of confidence in definition of a condition of springs it will be more correct to replace them.

Measurement of free length and check of a tortsovka of a valvate spring

  1. On petrol SOHC engines of release till September, 1995 saddles of springs of final valves are equipped with the rotators facilitating freedom of rotation of valves in the directing plugs. Turning manually, estimate a condition of rotators, in case of identification of breakthroughs and signs of a zakusyvaniye make replacement of defective components.
  2. Check plates of springs and crackers of their cutting locks for existence of cracks and signs of wear. All details which are in a doubtful state should be replaced new in order to avoid development of defects in the future.

Camshafts, pushers of valves and assembly of yokes with axes

The description of procedures of check of a condition of the listed components is provided in the Section Removal, check of a state and installation of valves. Assessment of a condition of bearing necks of camshafts has to be made before the head is sent a workshop for carrying out service of valves. Existence on necks of scratches, zadir and other mechanical defects a head is subject to replacement regardless of a condition of components of the valvate mechanism. At service of the SOHC engine it is also necessary to check a condition of yokes of the drive of valves with axes.

Replace all revealed defective components.

Grinding in of valves

At considerable degree of wear of components of valves that is quite probable for the engine needing capital repairs, collect valvate assemblies, establish them on the regular places in a head and you pass to performing procedures of service of valves. If the external condition of valves is found by satisfactory, measure by a micrometer diameters of their cores in several points. At identification of an essential difference of results the valve should be replaced.

For reliability of an overshoot valves of accesses to combustion chambers in operating time of the engine, at installation they should be ground in. Besides, grinding in allows to get rid of insignificant defects of the interfaced surfaces. Necessary smoothness of a surface of saddles after carrying out their machining can be reached only when using fine-grained pritirochny pastes. Before use of coarse-grained pastes (in the presence of serious damages or progar of saddles) consult with experts, - it is possible, replacement of a saddle or the valve will be the only acceptable way out.


  1. Before starting grinding of valves establish a head on a workbench by the surface interfaced to the block up.
  2. Apply a small amount of pritirochny paste of the required granularity on a valve saddle surface, then attach a sucker of pritirochny adaptation to an external surface of a plate of the valve. Rotary motions begin to grind in the valve to a saddle, from time to time raising it for the purpose of paste redistribution. Installation under a plate of the valve of a weak spring will help to facilitate a task. When using coarse-grained pastes try to achieve a dim opaque surface of the ground-in details. Having received desirable result, clear surfaces of an abrasive and repeat the procedure of grinding with use of fine-grained paste.
  3. Grinding in can be considered finished when on working surfaces of a saddle and a plate the indissoluble smooth opaque ring appears. As soon as the required result is achieved, grinding in should be stopped.
  4. Having finished grinding in of all valves, remove with kerosene or solvent all traces of an abrasive and pritirochny paste.