Service of Nissan Almera from 1995 to 2000 in N15 body
1. General information
2. General requirements to car repairs
3. Operation and maintenance of the car
4. Petrol engines
4.1. Removal and installation of the power unit
4.2. Dismantling and assembly of the engine
4.3. Block of cylinders
4.4. Conrod and piston group
4.5. Bent shaft and flywheel
4.6. Gas distribution mechanism
4.7. Head of the block of cylinders of GA14DE and GA16DE engines
4.8. Head of the block of cylinders of the SR20DE engine
4.8.1. Removal and installation of a cover of a head of the block of cylinders
4.8.2. Removal and installation of a forward cover of the drive of the mechanism of gas distribution
4.8.3. Removal and installation of a chain of the drive of camshafts
4.8.4. Removal of a head of the block of cylinders
4.8.5. Check of technical condition and installation of a head of the block of cylinders
4.8.6. Removal, check of technical condition and installation of camshafts
4.9. Cooling system
4.10. Lubrication system
4.11. System of production of the fulfilled gases
4.12. Power supply system
4.13. Complex Control System of the Engine (CCSE)
5. Diesel engines
6. Transmission
7. Running gear
8. Steering
9. Brake system
10. Electric equipment
11. Body
12. Appendices
13. Schemes of electric equipment
 









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4.8.6. Removal, check of technical condition and installation of camshafts

For removal of camshafts it is necessary to execute operations on removal of a chain and asterisks of the drive of camshafts (see above).
Further it is necessary to start removal of covers of support of camshafts. Be convinced available tags on chains of the drive and asterisks. In the absence of such tags install the piston of the first cylinder in VMT of a step of compression and put with tag paint for combination of a link of a chain and a point on an asterisk. For big reliability it is possible to tie each asterisk a wire to a chain.

Fig. 2.57. An arrow on a camshaft support cover


Mark covers of support before their removal. The arrow not to a cover of a support has to be turned towards a chain of the drive of camshafts (fig. 2.57).
The letter "I" (INLET) is applied on surfaces of covers of support of a shaft of inlet valves.

Fig. 2.58. Order of an inhaling of bolts of fastening of support of camshafts


In the sequence, return shown in fig. 2.58, weaken bolts of fastening of covers of camshafts on one turn, gradually reducing these pressure of springs of valves. Completely turn out and take out fastening bolts. Mark each bolt as they have different length.
Remove the maslootrazhayushchy screen and an oil pipeline. Uncover support and take out camshafts.
Check a condition of details. On the surface of contact of a head of the block of cylinders with covers of support risks, teases and so forth are not allowed.
Examine camshafts. On cams there should not be a facet, step and uneven wear, overheat traces (color of a pobezhalost) and other defects of a surface. Measure height of cams and diameter of necks of shaft. Measure a radial beating of camshafts, having installed them on prisms.
Measurement of a gap in support of shaft is taken by means of the special plastic calibrated wire as it is described for definition of gaps in bearings of a bent shaft.
Compare results of measurements to the values given in the main specifications.

Fig. 2.59. Extraction of the lever of the valve


Fig. 2.60. Extraction of hydropushers from a head of the block of cylinders


At the removed camshafts it is desirable to check technical condition of hydraulic pushers. For this purpose remove the valve lever from a head of the block of cylinders (fig. 2.59) and take out (without resorting to the help of a magnet) a hydropusher from an opening in a head of the block of cylinders (fig. 2.60).
Lay details according to their arrangement in boxes (cells). Remove a washer and the directing plug from a core of the valve and put them together with the lever of the valve. Repeat these operations for all levers of valves, hydropushers, the directing plugs and washers.
Check the basic surfaces of levers of valves, hydropushers, the directing plugs and a head of the block of cylinders; on them there should not be wear tracks and damages (zadir, scratches, забоин). Replace worn-out details.
Before installation of hydropushers check the size of wear of the washers established on an end face of valves. For this purpose install the directing plug on an end face of that valve from which it was removed.

Fig. 2.61. Installation of the indicator of hour type on the basic surface of the directing plug


Fig. 2.62. Turn of the indicator and installation of its head on a valve core end face


Fix the indicator of hour type on a head of the block of cylinders and bring its measuring core to the basic surface of the directing plug (fig. 2.61), i.e. in a guide cut. Establish in this situation an indicator scale on zero. Turn the indicator (having raised a measuring core) so that the measuring core rested against an end face of a core of the next valve of the same cylinder (fig. 2.62). You watch that the indicator support at measurement did not move. Calculate a difference of heights between an end face of a core of the valve and the basic surface of the directing plug and write down result. Return the indicator to initial situation and establish a measuring core on the basic surface of the directing plug. The arrow of the indicator has to show zero.
Execute measurements for each pair of inlet and final valves of each cylinder and write down results. On the basis of results of the specified measurements pick up washers of the necessary thickness for each pair of valves. The admission on thickness of a washer makes ±0,025 mm. Washers release thickness from 2,800 to 3,200 mm with an interval of 0,025 mm. The size is specified on a reverse side of a washer (so, "2875" designates that thickness of a washer of 2,875 mm). For measurement of thickness of the removed washer and definition of its wear it is possible to use a micrometer.

Fig. 2.63. Installation of washers and guides of plugs on valves


Put on washers valves (fig. 2.63). You watch that the marked parties of washers were turned down.
Before installation of hydropushers it is necessary to check them for availability of air in a cavity. Establish a hydropusher vertically and press it. Movement of a plunger of size more than 1 mm means availability of air in a hydropusher. In this case, and also at installation of a new hydropusher it is necessary to pump over it.

Fig. 2.64. Pumping of a hydropusher: 1 — a valve ball; 2 — a core; 3 — a plunger


Insert a metal core of suitable diameter into a hydropusher plunger opening. Place a hydropusher in vertical position in the vessel filled with pure engine oil (fig. 2.64). Having pressed a core, drown a valve ball then slowly several times press a plunger before the termination of an exit of vials of air. Repeat this operation several times and be convinced of lack of air in a hydropusher. Establish hydropushers in openings in a head of the block of cylinders. Install washers and the directing plugs on valves. Install levers of valves.

Fig. 2.65. Installation of camshafts in a head of the block of cylinders. Shooters showed adjusting pins


Fig. 2.66. Putting sealant on a cover of a support of the camshaft of final valves (the shaded area)


Oil pure engine support of camshafts and install camshafts. Make sure that the piston of the first cylinder of the engine is in compression step VMT. Install camshafts so that ledges of cams of the first cylinder were directed up. The adjusting pin on distributive to a shaft of inlet valves has to be in situation "10 hours" whereas an adjusting pin of the camshaft of final valves — in situation "12 hours" (fig. 2.65). To apply a sealant layer on the surface of interface of a cover of a support on the back end of the camshaft of final valves (fig. 2.66). On the tags made before removal establish covers of support on the places. Make sure that shooters on covers are directed towards a drive chain. Install the screen on a cover of the bearing No. 2 of the camshaft of final valves. Establish an oil pipeline and bolts of fastening of covers of support on the places and tighten them by hand. Tighten on one turn bolts of fastening of covers of support of the camshaft of inlet valves in the sequence specified fig. 2.58. At the same time covers have to concern a surface of a head of the block of cylinders. Tighten the set moment all bolts of fastening of covers. In the same way tighten bolts of fastening of covers of the camshaft of final valves. Establish a chain of the drive of camshafts and an asterisk. Be convinced of the correct arrangement of tags on asterisks and a chain of the drive. Establish bolts and washers of fastening of asterisks and tighten bolts the set moment. Install the ignition distributor. Attach a wire to the minus rechargeable battery.

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4.8.5. Check of technical condition and installation of a head of the block of cylinders
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4.9. Cooling system







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