Volkswagen Golf ll, Jetta II

1983-1992 of release

Repair and car operation

After dismantling of a head of the block to wash out all details in gasoline. To clear chambers of combustion and valves of a deposit.

To check by means of a metal ruler and щупов, whether the plane of the head adjacent to the block of cylinders is broken. A ruler put an edge on a head surface lengthways, across and on a diagonal in different places and measure shchupy a gap between it and the head plane. If the gap exceeds 0,1 mm, a head it is necessary прошлифовать.

Measurement of height of a head of the block of cylinders

Minimum admissible height of a head of the block:

 – for MN engines and 2G between the top and bottom planes of 135,6 mm;
 – for other engines between the bottom edge of an opening under an epiploon of a cam-shaft and the bottom plane of 119,3 mm.

If as a result of polishing the height of a head of the block turned out less specified, it is necessary to replace a head.

To check a lateral gap between valves and directing plugs. For this purpose to insert the valve into directing plug so that the end of a core of the valve was aflush with the upper edge of the plug. Then, shaking the valve in the horizontal plane from an emphasis against the stop, to measure by the indicator size of moving of a plate of the valve which will show a gap. If the gap exceeds 1 mm for plugs of inlet valves and 1,3 mm for plugs final, it is necessary to replace plugs. Before выпрессовать the old directing plug, it is necessary to measure, on what size she acts from a block head also to establish the new plug. Выпрессовывать the plug it is necessary through an opravka. Before a press fitting of the new directing plug it is necessary to heat up a block head to 70 ° With, to grease with engine oil an opening in a head and the new plug. To press the new plug follows through an opravka. Maximum admissible effort of a press fitting of 1 t. After a press fitting of the plug to check and if it is necessary, рассверлить an opening under the valve.

Measurement of distance (a) between a torets of a core of the valve and the top plane of a head of the block of cylinders

To check a condition of saddles of valves, on them there should not be wear tracks or an obgoraniye. If necessary it is possible прошлифовать saddles. Polishing make on the special grinder or the special machine. On engines with hydropushers of valves when polishing it is necessary to sustain the minimum size "a" (see fig. Distance measurement between a torets of a core of the valve and the top plane of a head of the block of cylinders). The size "a" for inlet valves of 35,8 mm, for the final – 36,1 mm. If the size "a" is less specified, normal work of hydropushers will be broken. Reduction of a working facet of a saddle of the valve, thus, should not exceed the size equal to a difference between the size "a" before polishing and minimum admissible size of the size "a". If polishing did not possible to restore a saddle of valves, them it is possible профрезеровать with the subsequent grinding in of valves. The sizes of saddles of valves are shown on fig. Sizes of a saddle of the valve.

Sizes of the valve

To check a condition of valves. If on working facets of valves wear tracks or an obgoraniye are appreciable, they need to be ground in to saddles. If damage of a working facet considerable, facets of inlet valves is possible прошлифовать. Working facets of final valves to grind grinding in is forbidden, allowed only. If grinding in did not possible to restore a working facet of the final valve, it is necessary to replace it. If on a working facet of valves there are deep scratches which cannot be deduced polishing or grinding in, and also valves погнуты, burned through or have cracks, valves are subject to replacement. When processing valves it is necessary to sustain the specified sizes (see fig. Sizes of the valve).

Valve grinding in to a saddle

PERFORMANCE ORDER

1. To put on the valve a spring. 2. To put on a working facet of the valve the pritirochny paste representing a mix of a small nazhdachny powder with engine oil. 3. To insert the valve with a spring into a block head, the spring thus should wring out the valve from a saddle. 4. To put on a valve core the adaptation for grinding in or on a plate of the valve a rubber sucker. 5. To turn the valve by means of the adaptation or a sucker in both parties, periodically slightly pressing the valve to a saddle. 6. At grinding in not to remove from a working facet of the valve and a saddle it is too much metal as the possible number of repairs of a saddle and the valve decreases and by that term of their service is reduced. 7. By the end of grinding in it is necessary to reduce quantity of a nazhdachny powder. When the ground-in surfaces become absolutely smooth and will accept equal gray color, message grinding in on pure engine oil. 8. An external sign of satisfactory grinding in is monophonic opaque gray color of a working facet of the valve and a saddle. After grinding in to wipe a saddle and the valve a pure rag. 9. To check tightness of the ground-in valve, it is necessary to establish it in a block head together with a spring and crackers. After that to put a head sideways and to fill in to the canal closed by the valve, kerosene. If during 10 mines kerosene does not filter into the combustion chamber, the valve is considered tight.

To check a condition of springs of valves. The springs having cracks, or broken should be replaced. It is possible to compare spring height to height of a new spring. If the spring which has been removed from the engine, below new, it is necessary to replace it.

To examine levers of valves. If on them wear in a place of contact of the lever with a cam-shaft cam is appreciable, the lever to replace. If on a surface of contact of the lever with the valve the dent is appreciable, a surface of the lever it is necessary прошлифовать.

To examine a camshaft. If on cams and necks there are deep scratches, developments or teases, a shaft to replace. To establish a shaft in bearings of a head of the block and to measure a lateral gap between shaft and a plate of fastening of the distributor of ignition (at MN engines and 2G – between shaft and a bearing No. 3 cover). If the gap exceeds 0,15 mm, to replace a shaft or a plate.

To measure diameters of necks of a cam-shaft which should be equal:

 – a forward neck – 31,45 mm;
 – an average neck – 39,95 mm;
 – a back neck – 40,45 mm.

The most admissible wear of necks of 0,25 mm. The cam-shaft of MN and NU engines has a cast ring between cams of the first cylinder. Diameter of necks of a cam-shaft of MN engines and 2G (with hydropushers of valves) 26,0 mm, the minimum admissible size of necks of 25,75 mm. If the measured diameter less admissible to replace. To check shaft palpation, having established it on prisms, on an average neck. Admissible palpation of a shaft of 0,02 mm. If palpation is more, to replace a shaft. To check and if it is necessary to clean oil channels in shaft necks.

To check a block head on lack of cracks, it is necessary to bring to one of openings of a shirt of cooling a hose for supply of the compressed air. To muffle all openings in a head wooden jams, to lower a head in a bath with water and to submit air. In places where there are cracks, there will be air bubbles. In the same way to check oil channels in a block head.