Check and adjustment of backlashes of valves
Every year or every 20,000 km
Valve clearances on all engines regulated warmed up, but the engine does not have to work. To set the engine after repair work required valve clearances in the Specifications are given values for the cold state. However, all the gaps need to check valves and, after cooling the engine. If necessary, adjust the valve clearance must be carried out preparatory work, t. E. The cylinder head cover is removed, unscrewed the spark plugs, and so on. D.
Valve clearance is measured between the end of the pusher and cam camshaft. Adjustment is carried out as follows:
- Rotate the crankshaft (if removed candle, it can be done in the V-belt) until the mark on the belt pulley will not coincide with TDC on the plate adjusting ignition. Piston cylinder 1 will be in the TDC position (see. Graphic below). If we now turn the shaft slowly from side to side, you will notice that the pusher of the first or fourth cylinder moves up and down, t. E. Valves overlap. If this occurs in valve cylinder 4, the piston of cylinder 1 is in the TDC position; Otherwise, turn the crankshaft by a half turn.
- Measure the valves of cylinder 1 and all valves are shown in the picture, and write down the clearance of each valve.
Measurement valve inlet camshaft (A) and the exhaust camshaft (B), when the piston of 1st cylinder is at TDC.
- To check the clearance probe must be inserted between the flat surface of the pusher and the cam, as shown in the illustration below. A sign is correctly adjusted gap is that first, the probe is pulled tight, then it is easier.
| || Checking valve clearance feeler gauge at the specified location. |
- Rotate the crankshaft by a half turn to the piston of 4th cylinder is in TDC position. Check that the nozzles of both jaws of the fourth cylinder face up and check valves (illustration below) as described above.
| || Measurement gaps valve when the piston cylinder 4 is located at TDC. |
- If the valve clearances are within an acceptable range, you can install the removed parts. Otherwise, the gap should be adjusted accordingly. It should be noted that, for the replacement of shims in the workshops of Nissan uses two specially adapted. In any case, there must be a strong magnetic rod. Tappet regulating valve must be pushed inward to eject the washer with a magnet.
- Rotate the crankshaft to the nose of the cam controlled valve facing up.
- Use a small screwdriver to turn the push rod to a notch on the edge of the point to the middle of the cylinder head.
- Now press the plunger inside a special tool or screwdriver and use a small screwdriver to move the puck to the side, so it can be removed with a magnetic bar. Assistant should thus hold down the plunger.
- Using a micrometer, measure the thickness of the washer. Although the puck and has the designation (TS 224 denotes the thickness of the washer 2.24 mm), the puck shall be measured, as it can be worn. From the values obtained on the basis of the following formula may be necessary to determine the thickness of the washer:
?«N?» - the thickness of a new washer, ?«R?» - the thickness of the old washers and "M" - the measured valve clearance.
- N = R + (0.37 M), - the intake valves
- N = R + (0.40 M), - the exhaust valves
- There are 50 shims with thicknesses from 2.00 to 2.98 mm and a pitch of 0.02 mm. From this list, select the washer closest to the calculated value of thickness. Designation thickness after installation should be at the bottom. When installing the washer again press the plunger in and install the washer in place with a magnet and a small screwdriver.
- All adjusted valve clearance after setting new goals recheck. As already mentioned, the gap should be checked for a warm engine.
- Install all the removed parts. Do not make a mistake when connecting the cables, ignition, as otherwise the engine will not start.