Skoda Felicia
+ Cars of the Skoda Felicia brand
+ Maintenance instruction
+ Routine maintenance
- Repair of the engine
+ Repair without extraction from the car of the petrol engine of 1.3 l
+ Repair without extraction from the car of the petrol engine of 1.6 l
+ Repair without extraction from the car of the diesel engine
- Dismantle of the power unit and capital repairs of the engine
Removal from the car of the power unit - preparation and precautionary measures, general information about a suspension bracket of the power unit
Removal, partition and installation of the power unit
Capital repairs of the engine - preliminary data
Dismantling, cleaning, check of a state and assembly of a head of cylinders
Removal, check of a state and installation of the camshaft and pushers of valves (engine of 1.3 l)
Removal and installation of an intermediate shaft (diesel engine)
Removal, check of a state and installation of conrod and piston assemblies
Removal and check of a condition of a bent shaft
Cleaning and check of a condition of the block of cylinders/case of the engine
Check of a state and selection of inserts of radical and conrod bearings of a bent shaft
Engine assembly order after performance of capital repairs
Installation of a bent shaft and check of working gaps of radical bearings
Installation of piston rings
Installation of conrod and piston assemblies on the engine and check of working gaps of conrod bearings
Initial start of the engine after completion of its capital repairs
+ Cooling systems, heating
+ Power supply system
+ Engine electric equipment
+ Coupling
+ Transmission
+ Power shafts
+ Brake system
+ Suspension bracket and steering
+ Body and finishing of salon
+ Onboard electric equipment
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Removal, check of a state and installation of conrod and piston assemblies
Marking on the piston bottom
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1 — the Shooter, specifying the direction of rotation of a bent shaft
2 — Registration number of manufacturer
3 — Date of issue |
4 — the Trademark of manufacturer
5 — Diameter of the piston (it is designated by letters And, In or C) |
Piston rings
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1 — the First (top) compression ring
2 — the Second (lower) compression ring |
3 — the Oil scraper ring |
Conrod and piston group - general information
Engine of 1.3 l
Pistons
Pistons are made of the aluminum alloy differing in the high thermal stability, considerable durability and hardness.
The piston consists of a skirt and the bottom. The form of a skirt provides a due prileganiye of the piston to sleeve/cylinder walls, excepting a possibility of its jamming in operating time.
In the piston in lugs the piston finger by means of which assembly fastens to the top head of a rod is established.
The opening axis under a piston finger is displaced concerning a piston axis. Such asymmetry aims at minimizing of the loadings arising during passing by assembly of VMT.
The pistons used in the considered engines have a bimetallic design: four steel corbels limiting the fluctuations of diameter of the piston connected with changes of temperature are provided in a zone of openings under a piston finger. Thanks to such protection became possible to lower gaps between walls of pistons and a mirror of cylinders to size of 0.02 mm.
On the surface of the piston three flutes under installation of piston rings are provided. Over a flute of the first (the top compression ring three additional flutes aiming at restriction of a thermolysis from the hot bottom of the piston to the top ring which is in the most severe operational conditions are executed.
Designations are applied on the bottom of the piston.
Pistons have to approach sleeves/cylinders, corresponding to them on dimensional groups. At installation of conrod and piston assemblies in the engine you watch that the tag in the form of an arrow was developed in a naprvleniye of rotation of a bent shaft (i.e. to the left on the engine).
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The surface of a skirt of the piston has irregular shape owing to what the measurement of diameter needs to be carried out strictly in the established place, at the height of 8 mm from the lower cut of a skirt. Measurement should be performed in the plane, a perpendicular axis of a piston finger. At the same time, temperature of both the piston, and the measuring tool has to equal 20 °C. |
Pistons are issued only the nominal sizes and are divided by diameter on three dimensional groups (And, In and C).
For the purpose of ensuring stable operation of the engine all four pistons have to have the same weight. Weighing of pistons is made for observance of this condition in the course of production. The dispersion of masses is corrected by removal of metal from a skirt.
Piston fingers
The piston finger provides hinged connection of the piston with a rod. The finger is made of high-quality steel, ground and polished. The top head of a rod sits down on a middle part of a finger. The ends of a finger are passed throughout openings in piston lugs. For fixing of the finger filled in assembly lock rings are used.
The new finger is established in the piston with a small tightness, without gap or with the minimum gap. In the plug of the top head of a rod the finger is put with a gap. At excessive a side play fingers at increase in load of the engine begin to knock.
Before installation of a finger from one of the parties of the piston the lock ring is established (use the special device for landing of a ring). Then, from the opposite side in the piston the piston finger which is slightly oiled motive refuels. The finger refuels so that its end acted in the piston at a size of 1 ÷ of 1.5 mm. Further in the piston the top head of a rod which is also slightly oiled motive refuels (track that the opening of a maslotok in the top part of a rod was directed aside, opposite, by the specified arrow applied on the piston bottom). Further fill a finger against the stop with its end face in the lock ring filled in the piston and establish the second lock ring on the other side of a finger.
Piston rings
Each of pistons is equipped with three piston rings established in the flutes which are specially done in the top part of walls of the piston. The form and an order of landing of rings in flutes are shown on an illustration.
The top compression ring is made of steel and chromeplated outside for the purpose of decrease in a component of friction, and also protection of metal against aggressive influence of the hot fulfilled gases. The ring has the correct round form and symmetric section in the form of a rectangle with the truncated corners.
The second (lower) compression ring is made of cast iron and has asymmetrical cross section in the form of a rectangle with inclined outer side. The tilt angle of an external side of a ring makes about 1 ° thanks to what the ring clip to a mirror of the cylinder is the share of very insignificant square. Wear of the contact platform provides ring prileganiye density.
On one of face surfaces of this ring there is a tag in the form of inscription "TORAHS". The ring should be installed on the piston by this tag up.
The oil scraper ring consists of three separate sections: two narrow side rings and the wavy dilator placed between them. The general thickness of assembly makes 3 mm.
The oil removed by a ring from a mirror of the cylinder is taken away through openings in a flute in the piston and, further, in the engine case pallet.
All piston rings have a cutting design. Cuts of rings are called locks, provide a possibility of installation of rings on pistons, and, besides, serve for compensation of thermal expansion.
The new ring most densely nestles on a cylinder mirror around the lock. In the course of further extra earnings the clamping effort is gradually leveled on ring perimeter, providing the maximum sealing of assembly.
Replacement of piston rings on the worn-out engine which cylinders got out of an initial shape leads only to short-term restoration of a compression as the ring cannot take the form of the worn-out cylinder and density of its prileganiye is distributed unevenly.
Rods
Rods are forged from special steel. The rod consists of the top head, a connecting core and the lower, cutting head. In the top head of a rod the bronze plug which is carrying out a bearing role under landing of a piston finger is pressed. The connecting core has double-T section. The lower head is cut in the plane, a perpendicular longitudinal axis of assembly.
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The surface of beds is carefully processed for installation of inserts of conrod bearings in a cutting lower head of a rod. As a result of such processing interchangeability of covers of conrod bearings is lost in view of what on covers and the lower heads special adjusting tags are provided. At factory assembly of a tag usually there correspond numberings of cylinders. |
The cover fastens to a rod by means of special bolts of the increased durability and two nuts with M9x1 carving.
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The through opening through which oil in operating time of the engine moves on cylinder walls is provided in the top head of a rod. At installation of a rod it is necessary to track that this opening was directed from the camshaft aside. |
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On weight rods are divided into two groups. More lungs (598 g weighing 590 ÷) are marked by the yellow tag applied on a head. On heavier rods (600 ÷ 609 g) the tag has blue color. All rods in the engine have to have identical weight at what at adjustment the mass of heavier rods is given to weight more lungs, and not vice versa. |
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The scheme of the procedure of measurement of a workshop of car service of a rod is shown on an illustration. During weighing the rod has to settle down horizontally. The difference of mass of the rods weighed both from lower and from top heads has to make no more than 2 ÷ of 6 g. Adjustment of weight is made by removal of material from the top head and a cover of the lower head in the places designated by shooters on an illustration. The maximum admissible thickness of the layer removed from the top head is limited to distance from the plane remaining after processing to an opening axis under installation of a piston finger. This distance has to make not less than 15 mm of durability reasons. In case of the lower head the distance is measured from the processed plane to an axis of the conrod bearing and has to make not less than 35 mm.
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Diesel engine and petrol engine of 1.6 l
In general the design of conrod and piston assemblies is similar described for engines of 1.3 l, with that difference that the possibility of installation of rods of the repair sizes is provided (see Specifications). Besides, in diesel engines rods are equipped by masloraspylitel of cooling of pistons.
REMOVAL
Engine of 1.3 l
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1. Remove a head of cylinders, the pallet of a case of the engine and a gear wheel of the oil pump. Make sure of reliability of landing of sleeves of cylinders, in case of need record them by means of special washers.
2. Check the lower heads of rods and a cover of conrod bearings for existence of identification tags in the form of the figures which are beaten out a side surface of components. Marking has to correspond to numbering of cylinders (the first the cylinder, the next to a gas-distributing chain is considered).
3. In case of need independently mark the lysk pierced on rods and their covers (use paint or a center punch).
4. Check an axial side play of rods, the probe of lezviyny type having measured gap size between their lower heads and cheeks of cranks. If the result of measurement exceeds the admissible value stipulated in Specifications, the corresponding rod should be replaced.
5. Having turned a bent shaft, bring pistons of the 2nd and 3rd cylinders into provisions of NMT.
6. Give fixing nuts and uncover the lower head of a rod with the insert of the conrod bearing of a bent shaft enclosed in it.
7. If dismantle is made only for the purpose of replacement of inserts, remove a rod from a shaft neck (try not to injure a neck of a shaft and a mirror of the cylinder - on hairpins of fastening of a cover of the bearing it is better to pull pieces of a fuel hose) and take the top insert of the bearing from its head.
8. Put the components removed from each of rods separately.
9. Remove components of the lower heads of rods of pistons of the 1st and 4th cylinders. Act extremely carefully not to damage a mirror of cylinders.
10. Remove a nagaroobrazovaniye step in the top part of each of cylinders. |
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Engines of 1.6 l and diesel
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1. Remove a head of cylinders, the case pallet, a maslootrazhatel, the oil pump and a maslozabornik.
2. Having lowered pistons in average situation, feel a finger of a mirror of cylinders, checking them for existence of step wear around the upper bound of the course of pistons. Steps have to be removed by means of a special vertical drill, otherwise it will be impossible to exclude probability of damage of pistons in the course of extraction of conrod assemblies.
3. To the Chertilky protsarapayta on the bottom of each of pistons number of the corresponding cylinder.
4. By means of the probe of lezviyny type measure an axial side play of landing of rods on necks of a bent shaft. Write down results of measurements.
5. On the diesel engine turn out fixing screws and take nozzles of masloraspylitel of cooling of pistons from the nests.
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6. Having turned a bent shaft, expose pistons of the 1st and 4th cylinders in provisions of NMT. In case of need to a nakernita on rods and covers of number of cylinders, an arrow designate orientation of covers concerning rods. |
7. Try to remember orientation of conrod and piston assemblies on the engine. Depending on type of the engine of assembly can are marked in various ways: on the party of the lower heads and their covers turned towards a gas-distributing belt dot tags, risks are put, or ledges on casting are provided various form. If factory marking does not manage to be found, put tags independently.
8. In stages (on a half-turn for approach) weaken bolts of fastening of a cover, uncover with the lower insert. In order to avoid confusion at assembly glue an insert to a cover an adhesive tape. Repeat the procedure for assembly.
9. The handle of the hammer push out assemblies via cylinders, take the top inserts and glue them an adhesive tape to rods.
10. Working in a former order remove conrod and piston assemblies of the 2nd and 3rd cylinders. |
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CHECK
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1. Having passed a flat sting of the small screw-driver throughout specially provided groove take a lock ring. Heat the piston to 60 °C. |
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2. Now the finger has to go out freely of the piston and an opening in the top head of a rod. |
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3. Arm with the special tool (or an edge of the old measuring probe) and remove piston rings from the piston. Do not forget that rings are made of fragile material and can easily break at an excessive dehiscence of locks - take care of protection of hands and eyes. The removed rings can be thrown out - at assembly they are subject to replacement without fail. |
4. Accurately remove with a fragment of an old ring coal deposits from flutes under installation of piston rings. Try not to damage walls and a bottom of flutes.
5. Carefully clear of a deposit of the bottom of pistons. After scraping of the main layer of deposits smooth out the bottom a wire brush or an emery paper.
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You watch safety of marking of pistons. |
6. Having finished cleaning, wash out flutes under installation of rings solvent, then carefully dry pistons. Make sure of passability of drainage maslovozvratny openings of flutes.
7. Check a condition of pistons. Normal wear is shown in the form of uniform vertical development on the persistent surface of the piston and is followed by weakening of landing in the flute of the top compression ring. In case of identification of traces of any abnormal wear the piston should be investigated attentively regarding suitability it to further use, then to try to reveal and remove a cause of infringement.
8. Presence on a skirt of the piston of scratches or zadir can be regarded as a result of the overheat caused by violation of serviceability of functioning of cooling systems or lubricants or inadmissible excess of temperature of combustion of air-fuel mix. Progara skirts usually are caused by break of gases from combustion chambers as a result of wear of cylinders or piston rings. The burn-out of the bottom of the piston testifies existence of violations of installation of a corner of an advancing of ignition and a mix detonation. Corrosion of the piston in the form of small cavities specifies on hit in the camera a combustion/case of the engine of cooling liquid. Try to establish the reasons of violations and to eliminate them.
9. Check rods, fingers and covers of the lower heads of rods for existence of cracks and other mechanical damages. Having laid rods on a flat surface, check them for existence of signs of deformations (in case of lack of confidence, ask for the help specialists of car service). Estimate a condition of plugs of the top heads of rods.
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10. By means of a micrometer measure diameters of all four pistons at distance of 10 mm from a cut of his skirt in the plane located at right angle to an axis of a piston finger. If the result of measurement exceeds the limit of the range stipulated in Specifications, the piston is subject to replacement.
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If in the course of performance of capital repairs the block of cylinders was exposed to boring, or replacement of sleeves (model of 1.3 l) was made, it is necessary to pick up a new set of pistons of the repair size. Write down results of measurements - they will be required later at calculation of gaps of landing of pistons in cylinders (see below). |
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11. Having enclosed a new piston ring in the corresponding flute on the piston, the probe of lezviyny type measure a landing gap of a ring. Serially check landing of each of piston rings. If the result of any of measurements exceeds the limit of admissible range, the piston is subject to replacement. Just in case check correctness of the choice of rings, having measured their thickness by a micrometer.
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12. Measure by Columbus of vernier type internal diameters of nests under landing of piston fingers in the top heads of rods. Then determine diameters of fingers). Subtracting results of the last from results of the first measurements, define gaps of landing of fingers in heads. Compare results of calculations to requirements of Specifications. In case of need the plug of a rod and a nest in the piston have to be pierced, and the finger is replaced new, the repair size. Performance of this work will be more correct to be charged to specialists of car service. |
13. On engines of 1.3 l rods are broken into two weight categories, on covers of the lower heads of rods the corresponding marking is put. Easier rods aim yellow paint, heavier - blue. When replacing rods it is necessary to select replaceable components from the same weight group. In case of lack of marking it is necessary to address for consultation experts company service center of the Skoda company.
14. Correctness of orientation of pistons on rods is determined by the marking applied on the bottoms (the bottom has to be cleared of a deposit).
15. On engines of 1.3 l the arrow applied on the bottom of the piston has to specify on the engine forward (towards an arrangement of an oil filter). The rod has to be razvernutmaslotoka back.
16. On models of 1.6 l and diesel engines of the shooter on the bottom of the piston it has to be developed towards a gas-distributing belt. The rod and a cover of its lower head are established by the pro-point done in their bases in the party specified by an arrow on the piston.
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17. Grease a piston finger and the plug of the top head of a rod with pure motive oil. Install the piston on a rod. Fix a finger by two lock rings, having developed them locks on 180 ° from removable grooves. Working in the same order, mount the remained conrod and piston assemblies. |
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