Citroen Xantia

1. Scratch out from interfaced surfaces of a head of cylinders all traces of a material of old laying. Be careful, try not to damage components.
2. Scratch out coal deposits from walls of chambers of combustion, and also inlet and final ports of a head. Carefully wash out a head kerosene or other suitable solvent.
3. Scratch out from surfaces of valves the main layer of coal deposits, then manually smooth out plates and cores of valves a wire brush.

1. Attentively check a head of cylinders on existence of cracks, traces of leakages of cooling liquid and other damages. The burst head is subject to replacement without fail. In case of absence of confidence of definition of a condition of a head, it is necessary to address for the corresponding consultations in a car-care center workshop.
2. By means of a planeness measuring instrument (the steel ruler put on an edge) and щупа lezviyny type check an interfaced surface of a head on existence of signs of deformation. If not planeness exceeds admissible value (see.), it is necessary to give to the specification a head to a pro-point in a mechanical workshop, or to replace it (in case the mekhobrabotka leads to reduction of height of a head below an admissible limit).

On diesel engines if at a mekhobrabotka from a head acts in film more than 0.1 mm of height, it will be necessary to pierce also chambers of combustion and a saddle of valves for the purpose of preservation of the proper dimensional correlations when landing plates of valves and directing plugs.

3. Check a condition of saddles of valves in each of combustion chambers. In case of identification of cavities, cracks or traces прогара, it is necessary to subject a head to the special regenerative repair which performance lies outside the limits of qualification of the average amateur mechanic and it should be entrusted to specialists of car-care center. If only insignificant defects are revealed, they can be eliminated in the course of performance of grinding in of valves (see below).
4. In case of wear of the directing plugs which characteristic sign is excessive lateral люфт the valves, being accompanied a dense dark blue smoke on an exhaust at operation of the engine, the plug are subject to replacement. Measure diameters of cores of the cylinders of valves removed from a head (see below), and also internal diameters of directing plugs. From the corresponding results of the second the gap of landing of valves in plugs is defined by a way of subtraction of results of the first measurements. Compare results of calculations to requirements of Specifications. If the size of landing gaps falls outside the limits an admissible range, it is necessary to make replacement of valves / their directing plugs. It will be more correct to charge performance of replacement of plugs to specialists of car-care center, at whose order there are all necessary tools.
5. Restoration of saddles of valves is made only after replacement of directing plugs.

6. On diesel engines check vortical chambers on existence прогаров, cracks and other this sort of damages. Existence of small threadlike cracks in walls of chambers is admissible. Replacement of chambers is made only in cases serious прогаров, deformations or weakening of landing in a head and should be charged to experts of a workshop of car-care center. By means of a tsiferblatny measuring instrument of plunzherny type measure height of a vystupaniye of vortical chambers. Null a measuring instrument, having rested a plunzher against a prokladochny surface of a head, then transfer it to a chamber end face. Compare results of measurements to requirements of Specifications. If the height of a vystupaniye of vortical chambers exceeds admissible value, it is necessary to address for council to experts Citroёn company service center.

1. Check plates of valves on existence of cracks, cavities and traces прогара. Estimate extent of operation of cores of valves. Check, whether there are no cracks in necks of cores. By rotation check valves on a bend of cores. Make sure of lack of cavities and signs of excessive wear of end faces of cores. Identification of any of the listed defects demands replacement of valves.

2. If during carrying out described above check the condition of valves is recognized satisfactory, measure a micrometer diameters of their cores in several points. Any appreciable difference in results made for each of valves of measurements indicates wear of its core and need of carrying out replacement.

3. Recognized suitable for further use valves should be ground in to the saddles for a guarantee of tightness of closing of chambers of combustion. If defects of a surface of saddles are only insignificant, they can be eliminated in the course of performance of such grinding in. Necessary smoothness of polishing of a surface of saddles after their regenerative pro-point can be reached only when using special pritirochny pastes. In case of detection of deep defects or прогаров grew gray a condition of a head of cylinders and valves it should be checked by the expert who then makes the decision on volume of recovery operations or even replacement of valves or their saddles.
4. For performance of grinding in establish a head upside down on a strong workbench.

5. Put a little pritirochny paste of demanded granularity on a surface of a saddle of the valve, then fix a sucker of the special pritirochny adaptation on an external surface of a plate of the valve. Reciprocating rotary motions of the adaptation start to grind in the valve to the saddle, from time to time, raising it for the purpose of paste redistribution. Placement under a plate of the valve of a weak spring will help to facilitate procedure performance essentially.

6. When using coarse-grained pritirochny paste try to achieve dim opaque coloring of ground-in surfaces of the valve and its saddle. Having received satisfactory result, wipe surfaces and repeat procedure with application of more fine-grained paste. It is possible to consider grinding in finished when on working surfaces of a saddle and a plate of the valve there are smooth equal continuous rings of opaque light gray color. It is not necessary to continue grinding in more long, than it is really necessary in order to avoid excessive understating of a working surface of a saddle.
7. Having finished grinding in of all valves, remove with pure rags all traces of paste. Before assembly wipe surfaces kerosene.

1. Check klapanny springs on existence of mechanical damages and overheat traces (coloring change). Whenever possible compare free length of the removed springs to length of the new.
2. Establishing each of springs vertically on a flat surface, check severity of their tortsovka. Springs with tortsovka violation, it is equal as weakened and given, are subject to replacement. Replacement of springs is usually made in a set and, whenever possible, without fail.
3. Replacement of maslootrazhatelny caps of cores of valves is made also without fail, regardless of their condition.