Daewoo Nexia

Since 1994 of release

Repair and car operation

2.30.2. Diagnostics of malfunctions of pushers

THE GENERAL DATA

1) the Temporary raised noise of valves right after engine start is the normal phenomenon. This noise speaks that from a part of pushers which at the idle engine were under loading клапанных springs of open valves, oil has flowed out. Some seconds after engine start that hydrojacks of backlashes have started to work normally Are required.

2) Faltering noise idling the engine, stopping at increase in turns of a shaft, can be a sign of defect of a surface of a ball of the return valve or pollution of the mechanism of the hydrojack.

Elimination

PERFORMANCE ORDER

1. To clear and examine pusher details. 2. To replace the worn out ball of the return valve.

3) the Raised noise at small frequency of idling or on completely heated-up engine. Noise vanishes on the cold engine or at increase in speed of rotation of a cranked shaft. The reason concludes ся in the big leaks of oil in a backlash between плунжером and a pusher. To replace the worn out pusher.

4) the Raised noise at high speeds of movement of the car, vanishing on small speeds, can be caused following reasons:
      – Unduly high level of oil (above a label the MOVE on probeе). Intensive hashing and oil agitation by cranked shaft leads to hit of a peno-air oil mix in hydrojacks of pushers. It causes abnormal work of hydrojacks;
      – Insufficient level of oil (below label MIN on probeе). Leads засасыванию air the oil pump and abnormal work гидрокомпенсато a ditch of backlashes. Elimination to add oil and to finish its level to norm;
      – Will drive the oil pallet, the intaking oil filter or ослабло its fastening has risen. To replace or repair defective details, to tighten fixing bolts.

5) the Raised noise idling the engine, increasing with growth of turns of a cranked shaft to 1500 rpm. This noise is not connected with work of pushers. At low frequency of idling noise can vanish or be shown absolutely, as easy knock of one or several valves. The following can be the possible reasons:
      – Strong deterioration of a tip of the valve or the lever;
      – The big backlashes between cores of valves and directing plugs;
      – Big несоосность the valve and a saddle;
      – непараллельность end faces клапанных springs;
      – The big palpation of a facet of a head of the valve;
      – Contact демпфера клапанной springs with the mechanism of rotation of the valve.

For check of a condition of a spring and backlashes in directing plugs it is necessary to uncover клапанного the mechanism.
Sometimes it is possible to get rid of this noise having turned a spring or the valve a little. To turn a cranked shaft in position at which the suspicious valve will rise from a saddle. To turn a spring. Simultaneously will turn ся and the valve. Similar adjustment to achieve silent work of the valve. If turn of a spring and the valve does not give result, to check up a spring condition. If deformation of a bend of a spring in a free condition exceeds 1,6 mm, to replace a spring.
To check up backlashes between cores and directing plugs of valves. To eliminate the increased backlashes.

6) the Constant noise which is not dependent on frequency of rotation of a cranked shaft. The possible reasons are the increased thermal backlashes in a drive of valves or hit in the mechanism of alien particles. To check up thermal backlashes of valves, having established the piston of the corresponding cylinder in the top dead point on a compression step. In the presence of a backlash the pusher bar freely moves upwards and downwards between a cam and the valve lever. If a backlash normal, it is necessary to clear the pusher hydrojack.