At rather small expense of fuel the engine shows the best return of capacity only when piston rings provide good tightness. To define, valves and piston rings a manometre are how much tight check a compression of separate cylinders. For the diesel engine the special adapter which is rolled instead of an atomizer in a head of the block of cylinders also is necessary. Recommended Volkswagen the adapter has number 1323/2A. Besides, the minimum one sealing ring of thermal isolation as at compression check it is not necessary to use the established sealing rings is required to you.

The engine should be нагрет to working temperature that piston rings provided the best tightness.

Fig. 450. Check of work of a candle накаливания by means of tester Volkswagen. Instead of a tester the manometre can be twisted in the specified place for a candle накаливания

The compression also can be measured in apertures of candles накаливания. However the corresponding adapter (fig. 450) again is required to you. Such adapter is used Ford (GV2168).

Depending on what adapter will be used, operate as follows.

Compression measurement in apertures of candles накаливания

Take out the relay of the fuel pump from the block of safety locks (a place of the driver, space for feet). The relay is designated R13.

Start the engine. After some time it will stop (fuel receipt) is blocked.

Fig. 391. Removal of a cover of the engine: 1 — a hose of forced air; 2 — заглушка

Uncover the engine as it has already been described at removal of a head of the block of cylinders (see fig. 391).

Disconnect the electric tyre of candles накаливания from штырьковых conclusions.

Turn out candles накаливания and wrap on their place a corresponding adapter. At first twist an adapter in the first cylinder.

Twist a manometre in an adapter.

Ask the assistant to turn the engine a starter. Scroll the engine until while the arrow of a manometre will not show the greatest value, i.e. the arrow will not rise any more.

Check up by turns other cylinders.

In summary again establish all removed details. If the engine is not got, you have for certain forgotten to establish to the place of the relay of the fuel pump.

Compression measurement in apertures of atomizers

Take out the relay as it has been described, and allow to the engine to work until it will not decay. Also it is possible to disconnect a cable from the device of a stopping delivery of fuel on ТНВД and to isolate it. The cable in this case should be unbent aside.

Remove all топливопроводы a high pressure from atomizers and remove atomizers (see the corresponding has undressed). Put atomizers on a pure fabric or a paper.

Fig. 451. The manometre 1 together with an adapter 2 is twisted in an atomizer aperture

Twist an adapter with a sealing ring of thermal isolation in the first aperture of an atomizer and connect it to a manometre (fig. 451).

Ask the assistant to turn the engine a starter. Scroll the engine until while the arrow of a manometre will not show the greatest value, i.e. the arrow will not rise any more.

Check up by turns other cylinders.

It is considered normal if value of a compression in one of cylinders does not fall below 80 % from the best result received at measurement of any cylinder. The low, unequal compression in different cylinders grows out of deterioration of piston rings that it is possible to define also under the raised expense of oil. At a good compression its size should be not less than 19,0 bar. The nominal size of a compression makes 25—30 bar. On the basis of comparison of the sizes received at measurement with rating value of a compression you can easily define degree of deterioration of corresponding details.

If the received result of measurement approximately is equal to size of border of deterioration it is necessary to fill in a few engine oil in the engine through an aperture of a spark plug and to repeat measurement. If the result has appeared now better it is possible to assume that the reason of a low compression are the worn out piston rings or the developed walls of the cylinder. If the received result remained approximately the same the reason of a low compression most likely is one or a little badly working valves. Also there can be not tight a lining of a head of the block of cylinders. In any case it is necessary to remove a head of the block of cylinders and to spend careful check for definition of a cause of defect.

Again remove a manometre and establish atomizers with rings of thermal protection as it is described in corresponding section.