Daewoo Nexia

since 1994 of release

Repair and car operation

1) The temporary increased noise of valves right after start of the engine is the normal phenomenon. This noise speaks that from a part of pushers which at the idle engine were under loading of klapanny springs of open valves, oil flowed out. Some seconds after engine start that hydrojacks of gaps 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 a worn-out ball of the return valve.

3) The increased 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 big leakages of oil in a gap between a plunzher and a pusher. To replace a worn-out pusher.

4) The increased noise at high speeds of movement of the car, vanishing on small speeds, can be caused by the following reasons:
      – unduly high level of oil (labels the MOVE on щупе are higher). Intensive hashing and oil agitation by cranked shaft leads to hit of a peno-air oil mix in hydrojacks of pushers. It causes abnormal operation of hydrojacks;
      – insufficient level of oil (MIN labels on щупе are lower). Leads to an air zasasyvaniye the oil pump and abnormal work гидрокомпенсато a ditch of gaps. Elimination to add oil and to finish its level to norm;
      – will bend the oil pallet, the intaking oil filter rose or weakened its fastening. To replace or repair defective details, to tighten fixing bolts.

5) The increased 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 wear of a tip of the valve or lever;
      – big gaps between cores of valves and directing plugs;
      – big not coaxiality of the valve and saddle;
      – not parallelism of end faces of klapanny springs;
      – big palpation of a facet of a head of the valve;
      – contact of a damper of a klapanny spring to the mechanism of rotation of the valve.

For check of a condition of a spring and gaps in directing plugs it is necessary to uncover the klapanny 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 situation at which the suspicious valve will rise from a saddle. To turn a spring. At the same time will turn ся and the valve. Similar adjustment to achieve silent operation of the valve. If turn of a spring and the valve does not give result, to check 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 gaps between cores and directing plugs of valves. To eliminate the increased gaps.

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