On engines hydraulic pushers which automatically compensate a gap between cams of a camshaft and the corresponding rods of valves are established. Check and adjustment of klapanny (thermal) gaps on such engines are not required. However for no-failure operation of pushers it is necessary to use the engine oil recommended by manufacturer, and to replace it through demanded intervals of operation. At start-up of the cold engine there can be a knock of valves which lasts about 10 with until pressure of oil in system of greasing will not rise to necessary size and hydraulic pushers do not liquidate gaps. If the engine did not start up within several days, knock of valves can proceed and more long. Thus it is necessary to avoid sharp change of frequency of rotation of a cranked shaft not to damage hydraulic pushers. At engine warming up the maximum frequency of rotation of a cranked shaft should not exceed 2000–2500 mines-1 during 10–15 mines or before the termination of knock of valves.

Removal of a camshaft and hydraulic pushers

If knock does not stop, it is necessary to check serviceability of pushers. For this purpose it is necessary to execute the following operations:

– disconnect and remove elements of system of injection of fuel;

Fig. 3.8. Head of the block of cylinders of SOHC engines: 1–head of the block of cylinders; 2–laying of a head of the block of cylinders; 3–the directing plug of the valve; 4–maslootrazhatel; 5–laying of a cover of a head of the block of cylinders; 6–cover of a head of the block of cylinders; 7–power strip; 8–stopper of a maslonalivny mouth; 9–bolt of fastening of a head of the block of cylinders; 10-hairpin of fastening of a cover of a head of the block of cylinders; 11-nut of fastening of a cover of a head of the block of cylinders; 12-forward laying of a cover of a head of the block of cylinders; 13-cap

Fig. 3.9. Head of the block of cylinders of DOHC engines: 1–head of the block of cylinders; 2–laying of a head of the block of cylinders; 3–the directing plug of the valve; 4–a bolt 5, 6 – laying of a cover of a head of the block of cylinders; 7–bolts of fastening of a cover of a head of the block of cylinders; 8–cover of a head of the block of cylinders; 9–stopper of a maslonalivny mouth

– uncover 6 (fig. 3.8, 3.9) of a head of the block of cylinders;

– remove a maslootrazhatel 4 (see fig. 3.8 ) and laying 5 (see fig. 3.8, 3.9 ) covers of a head of the block of cylinders;

– rotate a cranked shaft before cam installation over a checked pusher a working surface up;

Fig. 3.10. Check of a free wheeling of a pusher

– press a pusher a wooden or plastic wedge (fig. 3.10) . If a free wheeling of a pusher more than 0,1 mm, replace a pusher.

For removal of a camshaft and pushers execute the following operations.

For all engines:

– establish the piston of the first cylinder in VMT of a step of compression (see подразд. 3.1.4);

– remove the top cover of a belt of a drive of a camshaft;

– weaken a tension of a belt of a drive of a camshaft and remove it only from a camshaft cogwheel, having left it in gearing with other cogwheels of other shaft;

– fix the top end of a belt of a drive of a camshaft so that to keep its tension;

– unscrew a bolt of fastening and remove a gear pulley of a camshaft.

For SOHC engines:

– remove laying 12 (see fig. 3.8 ) covers of the No. bearing of 1 camshaft and the rubber cap 13 established in a back part of a head of the block of cylinders;

Fig. 3.11. Head of the block of cylinders of the SOHC engine and mechanism of a drive of valves: 1–camshaft; 2–cover of the No. bearing of 1 camshaft; 3–cover of the No. bearing 2 camshafts; 4–cover of the No. bearing 3 camshafts; 5–cover of the bearing No. 5 of a camshaft; 6–gear pulley of a camshaft; 7–bolt of fastening of a pulley of a camshaft; 8–head of the block of cylinders; 9–hydraulic pusher; 10-valve crackers; 11-plate of a spring of the valve; 12-external spring of the valve; 13-internal spring of the valve; 14-maslosjemny cap; 15-bottom plate of a spring of the valve; 16-the directing plug of the valve; 17-valve; 18-cuff; 19-cap; 20-nut of fastening of a cover of the bearing; 21-segment shponka; And — a place of drawing of alphabetic marking of a camshaft; B – a place of drawing of digital marking of a camshaft

– put labels of serial numbers and provisions of covers 2, 3, 4, 5 (fig. 3.11) of bearings of a camshaft 1 for the subsequent their correct installation;

– unscrew nuts of the 20th fastening of covers of bearings No. 1 and 3, then No. 2 and 5. Nuts it is necessary to turn on serially cross-wise on a half of turn for one pass until they cannot be turned on manually;

– remove covers 2, 3, 4, 5 bearings;

– remove a camshaft 1.

For DOHC engines:

Fig. 3.6. Provision of adjusting labels of asterisks of camshafts of the DOHC engines, corresponding VMT of the piston of the first cylinder

– be convinced that the piston of the first cylinder is established in VMT of a step of compression, wipe oil from a chain of a drive of a camshaft of inlet valves, check coincidence of adjusting labels on asterisks of camshafts (see fig. 3.6 ) if labels are absent, put them on asterisks;

Fig. 3.12. Head of the block of cylinders of the DOHC engine and mechanism of a drive of valves: 1–camshaft of final valves; 2–camshaft of inlet valves; 3–gear pulley of a drive of a camshaft of final valves; 4–bolt of fastening of a gear pulley; 5–asterisk of a camshaft of final valves; 6–asterisk of a camshaft of inlet valves; 7–chain of a drive of a camshaft of inlet valves; 8–hydraulic pusher; 9–valve crackers; 10-top plate of a spring of the valve; 11-external spring of the valve; 12-internal spring of the valve; 13-maslosjemny cap; 14-bottom plate of the valve; 15-the directing plug of the valve; 16-covers of bearings of camshafts; 17-nuts of fastening of covers of bearings of camshafts; 18-valves; 19-head of the block of cylinders (GBTs); 20-GBTs laying; 21-bolt of fastening of GBTs; 22-cuff of a camshaft of final valves; 23-cover of the forward bearing of a camshaft of final valves; 24-cover of the back bearing of a camshaft of final valves; 25-segment shponka

– put labels of serial numbers and provisions of covers 16 (fig. 3.12) for the subsequent their correct installation;

– weaken alternately nuts of the 17th fastening of covers of 16 bearings No. 5, 7 and 9 of a camshaft of 2 inlet valves;

– unscrew nuts of the 17th fastening of covers of bearings No. 6 and 8. Nuts it is necessary to turn on serially cross-wise on a half of turn for one pass until they cannot be turned on manually;

– weaken alternately nuts of the 17th fastening of covers of 16 bearings No. 1, 3 and covers 23, 24 camshafts of 1 final valves;

– unscrew nuts of the 17th fastening of covers of bearings No. 2 and 4. Nuts it is necessary to turn on serially cross-wise on a half of turn for one pass until they cannot be turned on manually;

remove camshafts 1 and 2 together with a chain 7.

For all engines:

– take out hydraulic pushers 9 (see fig. 3.11 ) or 8, (see fig. 3.12 ) by means of rubber присоса, place the removed pushers in the container filled with fresh engine oil, as their removal for the subsequent their correct installation on the places.

Fault detection of a camshaft and hydraulic pushers

In the presence of a konusnost of a lateral surface of a pusher, it is necessary to replace it. If after start-up of the cold engine knock of valves proceeded a long time, and at check it appeared that pushers are serviceable, it is necessary to replace engine oil and the oil filter.

Examine cams and camshaft necks. In the presence of cracks, scratches, traces of dot corrosion and wear it is necessary to replace them.

Examine asterisks of camshafts and a chain of a drive of a camshaft of inlet valves. If teeths of asterisks are worn-out or damaged, it is necessary to replace asterisks and camshafts.

Examine working surfaces of bearings of a camshaft. At existence on them of cracks, scratches, traces of dot corrosion and wear repair of a head of the block of cylinders in a specialized workshop or its replacement is necessary.

Measure by a micrometer diameters of necks of a camshaft in several places everyone. If at least one neck less nominal, a camshaft it is necessary to replace diameter.

Fig. 3.13. Determination of size axial люфта camshaft

For definition axial люфта a camshaft remove hydraulic pushers, clear working surfaces of bearings of a camshaft, establish a camshaft and covers of bearings. Measurement axial люфта by means of the indicator of hour type (fig. 3.13) is carried out in the following sequence:

– establish a support of the indicator of hour type;

– establish the indicator, thus its measuring core should rest against a camshaft end face;

– move a camshaft against the stop towards the indicator;

– establish on zero of the indication of the indicator;

– move a camshaft to the opposite side against the stop;

– determine size axial люфта a camshaft by indicator indications.

If value люфта exceeds admissible, measure repeatedly. If at repeated measurement люфт remains, it is necessary to replace a camshaft and/or a head of the block of cylinders. Consult with the expert.

Installation of hydraulic pushers and camshaft

Before installation of a new camshaft be convinced that it corresponds to engine model. For camshaft identification on it выштампованы alphabetic And (see fig. 3.11 , tab. 3.3 ) and digital B of marking.

Assembly of a head of the block of cylinders is carried out in the following sequence.

For all engines:

– grease hydraulic pushers and nests for their installation in a head of the block of cylinders;

– establish hydraulic pushers on the places;

For SOHC engines:

– grease necks and camshaft cams with engine oil and establish a shaft in a bed of a head of the block of cylinders so that cams of the first cylinder were directed up;

– establish covers 3 and 5 (see fig. 3.11 ) bearings No. 2 and 5;

– tighten nuts of the 20th fastening of covers of bearings No. 2 and 5 serially cross-wise on a half of turn for one pass by the moment of 10 N · m;

– establish covers of 2 and 4 bearings No. 1 and 3;

– tighten nuts of the 20th fastening of covers of bearings No. 2 and 5 serially cross-wise on a half of turn for one pass by the moment of 10 N · m;

– grease working edges of a cuff 18, establish a cuff on a camshaft and by means of an opravka insert into a head of the block of cylinders;

– establish a new rubber cap 19 and forward laying 12 (see fig. 3.8 ) covers of a head of the block of cylinders.

For DOHC engines:

– establish a chain 7 (see fig. 3.12 ) a drive of a camshaft of inlet valves to such images that adjusting labels were against each other;

– establish camshafts in a bed of bearings and check coincidence of adjusting labels (see fig. 3.6 );

– establish a new cuff 22 (see fig. 3.12 ) for the forward end of a camshaft of final valves, previously having greased it working edges with engine oil;

– establish covers of 16 bearings No. 6 and 8 of a camshaft of inlet valves on the places in compliance with numbering, having directed cuts on corners of covers to an inlet collector;

– tighten nuts of the 17th fastening of covers of bearings No. 6 and 8 serially cross-wise on a half of turn for one pass by the moment of 15 N · m;

– establish a cap of a back part of a head of the block of cylinders;

– establish covers of 16 bearings No. 5 and 7, having directed cuts on corners of covers should to an inlet collector;

– tighten nuts of the 17th fastening of covers of bearings No. 5 and 7 the moment of 15 N · m;

– establish covers of 16 bearings No. 2 and 4 of a camshaft of final valves so that cuts on corners of covers were directed to an inlet collector;

– tighten nuts of the 17th fastening of covers of bearings No. 2 and 4 serially cross-wise on a half of turn for one pass by the moment of 15 N · m;

– establish covers 23 and 24 and covers of 16 bearings No. 1 and 3 of a camshaft of final valves and serially tighten nuts of 17 covers the moment of 15 N · m;

– grease working edges of a cuff 22, establish it on a camshaft and by means of an opravka insert into a head of the block of cylinders.

For all engines:

– establish a segment shponka 21 (see fig. 3.11 ) or 25 (see fig. 3.12 ) and a gear pulley 6 (see fig. 3.11 ) or 3 (see fig. 3.12 ) a camshaft of final valves;

– establish a belt of a drive of GRM and adjust its tension (see подразд. 3.1.4);

– establish a maslootrazhatel 4 (see fig. 3.8 ) and a cover of a head of the block of cylinders;

– establish elements of system of injection of fuel.

PREVENTION If hydraulic pushers removed or replaced, do not start up the engine during 30 mines after its assembly. This time is necessary for an exit from a pusher of excessive oil. Otherwise impact of valves and the piston is possible.