Hydraulic pushers which automatically compensate a gap between cams of the camshaft and the corresponding rods of valves are installed on engines. Check and adjustment of valvate (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 the required operation intervals. At launch of the cold engine there can be a knock of valves which lasts about 10 with until oil pressure in the lubrication system does not rise up to the necessary size and hydraulic pushers do not liquidate gaps. If the engine was not launched within several days, the knock of valves can longer continue. At the same time it is necessary to avoid sharp change of frequency of rotation of a bent shaft not to damage hydraulic pushers. At warming up of the engine the maximum frequency of rotation of a bent shaft should not exceed 2000–2500 min.-1 within 10–15 min. or before the termination of knock of valves.

Removal of the camshaft and hydraulic pushers

If the 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 valve plug; 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 an oil-filling 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 valve plug; 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 an oil-filling 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 bent shaft before installation of a cam over the 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 the free wheeling of a pusher is more than 0,1 mm, replace a pusher.

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

For all engines:

– install the piston of the first cylinder in compression step VMT (see subsection 3.1.4);

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

– weaken a tension of a belt of the drive of the 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 the drive of the camshaft so that to keep its tension;

– turn off a bolt of fastening and remove the cogged pulley of the camshaft.

For SOHC engines:

– remove laying 12 (see fig. 3.8 ) covers of the bearing No. 1 of the 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 the drive of valves: 1 – camshaft; 2 – cover of the bearing No. 1 of the camshaft; 3 – cover of the bearing No. 2 of the camshaft; 4 – cover of the bearing No. 3 of the camshaft; 5 – cover of the bearing No. 5 of the camshaft; 6 – cogged pulley of the camshaft; 7 – bolt of fastening of a pulley of the camshaft; 8 – head of the block of cylinders; 9 – hydraulic pusher; 10 – valve crackers; 11 – plate of a valve spring; 12 – external spring of the valve; 13 – internal spring of the valve; 14 – oil scraper cap; 15 – lower plate of a valve spring; 16 – the directing valve plug; 17 – valve; 18 – cuff; 19 – cap; 20 – nut of fastening of a cover of the bearing; 21 – segment spline; And — the place of drawing alphabetic marking of the camshaft; B – the place of drawing digital marking of the camshaft

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

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

– uncover 2, 3, 4, 5 bearings;

– remove the camshaft 1.

For DOHC engines:

Fig. 3.6. The provision of adjusting tags of asterisks of camshafts of DOHC engines corresponding to VMT of the piston of the first cylinder

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

Fig. 3.12. Head of the block of cylinders of the DOHC engine and mechanism of the drive of valves: 1 – camshaft of final valves; 2 – camshaft of inlet valves; 3 – cogged pulley of the drive of the camshaft of final valves; 4 – bolt of fastening of the cogged pulley; 5 – asterisk of the camshaft of final valves; 6 – asterisk of the camshaft of inlet valves; 7 – chain of the drive of the camshaft of inlet valves; 8 – hydraulic pusher; 9 – valve crackers; 10 – top plate of a valve spring; 11 – external spring of the valve; 12 – internal spring of the valve; 13 – oil scraper cap; 14 – lower plate of the valve; 15 – the directing valve plug; 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 (HBC); 20 – laying of GBTs; 21 – bolt of fastening of GBTs; 22 – cuff of the camshaft of final valves; 23 – cover of the forward bearing of the camshaft of final valves; 24 – cover of the back bearing of the camshaft of final valves; 25 – segment spline

– make tags of serial numbers and provisions of covers of 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 the camshaft of 2 inlet valves;

– turn off nuts of the 17th fastening of covers of bearings No. 6 and 8. Nuts need to be turned off serially cross-wise half way for one pass until they cannot be turned off 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;

– turn off nuts of the 17th fastening of covers of bearings No. 2 and 4. Nuts need to be turned off serially cross-wise half way for one pass until they cannot be turned off 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 a rubber prisos, 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 the camshaft and hydraulic pushers

With conicity of a side surface of a pusher, it needs to be replaced. If after launch of the cold engine the knock of valves continued a long time, and when checking it turned out that pushers are serviceable, then it is necessary to replace engine oil and an oil filter.

Examine cams and necks of the camshaft. In the presence of cracks, scratches, traces of pointed corrosion and wear they need to be replaced.

Examine asterisks of camshafts and a chain of the drive of the camshaft of inlet valves. If teeths of asterisks are worn-out or damaged, asterisks and camshafts need to be replaced.

Examine the working surfaces of bearings of the camshaft. In the presence on them cracks, scratches, traces of pointed 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 the camshaft in several places everyone. If diameter at least is less than one neck nominal, then the camshaft needs to be replaced.

Fig. 3.13. Determination of size of an axial side play of the camshaft

For definition of an axial side play of the camshaft remove hydraulic pushers, clear the working surfaces of bearings of the camshaft, install the camshaft and covers of bearings. Measurement of an axial side play by means of the indicator of the sentry like (fig. 3.13) is carried out in the following sequence:

– establish a support of the indicator of hour type;

– install the indicator, at the same time its measuring core has to rest against a camshaft end face;

– move the camshaft against the stop towards the indicator;

– set to zero indications of the indicator;

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

– determine the size of an axial side play of the camshaft by indications of the indicator.

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

Installation of hydraulic pushers and camshaft

Before installation of the new camshaft be convinced that it corresponds to engine model. For identification of the camshaft of a vyshtampovana on it 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 cams of the camshaft 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-turn for one pass 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-turn for one pass the moment of 10 N · m;

– grease working edges of a cuff 18, install a cuff on the camshaft and by means of a mandrel 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 ) the drive of the camshaft of inlet valves to such images that adjusting tags were against each other;

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

– establish a new cuff 22 (see fig. 3.12 ) on the forward end of the camshaft of final valves, previously having oiled its working edges engine;

– establish covers of 16 bearings No. 6 and 8 of the 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 half way for one pass 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 have 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 the 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 half way for one pass the moment of 15 N · m;

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

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

For all engines:

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

– establish a belt of the GRM drive and adjust its tension (see subsection 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 were removed or replaced, do not launch the engine within 30 min. 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.