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Check clearance in the valve mechanism in the engine M and M 102,980 102.982

The principle of the hydraulic valve clearance compensation

On engines of 102,980 M and M 102.982 rocker arms have hydraulic tappets.

Hydraulic valve lifters

1 - collection chamber 2 - working chamber 3 - pusher 4 - Rocker	5 - return spring ball valve 6 - a pusher plate 7 - thrust washer pusher

During engine operation in a cumulative 1 and 2 working chamber receives oil under low pressure (less than 3 kg / ^cm 2). This ensures constant contact pusher 3 with the valve stem. When lifting rocker 4 cam follower enters the rocker, the ball valve is closed, which causes an increase in pressure in the working chamber. By virtue of the incompressibility of the oil is provided by the transfer of the pusher and the valve movement of the cam and rocker arm. 5 spring provides constant pressure to the valves and the pusher with the engine stopped.

Check

If there are doubts about the failure of pushers (knock deterioration of the engine), check their condition.

PERFORMANCE ORDER

Remove the cylinder head cover. Rotate the crankshaft by hand, so that his head was turned to the rocker cam camshaft. Measure the progress of the pusher all the way to the yoke. If the stroke exceeds 0,5-2,4 mm, change the thickness of a spherical dish 6 or thrust washer 7 pusher. If one of the pushers is lowered more quickly than others, then it should be discarded and replaced.