How to overhaul an engine. How to overhaul the engine? Washing the engine and individual parts after disassembly

17.10.2019

Transmission

In our previous article, we wrote that due to the economic crisis and the rise in the price of imported spare parts, the overhaul of internal combustion engines (ICE repair) is once again becoming relevant and economically feasible. In this article, we will talk about the main methods and technologies that are used in the restoration of damaged and worn engine parts.

Before carrying out a major overhaul of a car engine, it is completely disassembled, after which all parts are washed and defective. This is a prerequisite for ensuring a high quality result of the ICE repair, since wear products and parts of damaged parts can get into the cooling jacket or block the oil channel, which will lead to repeated failure of the repaired engine.

Cylinder block before starting repairs, they are checked in a special pressure bath for hidden cracks. Identified shallow damage to the repaired car engine is first drilled to the base with a cutter, and then boiled with metal. With the help of welding, the holes punched by the connecting rod in the block of the repaired internal combustion engine are also closed, as well as the damaged partitions between the cylinders are restored. It should be noted that blocks made of aluminum and aluminum alloys are easier to cook than cast iron, as they have a lower melting point. Holes in cast iron blocks are eliminated with cast iron patches.

Cylinder block boring

Worn or damaged cylinder walls are bored to repair size and larger diameter pistons and piston rings are used. But this method of repairing an internal combustion engine is applicable only to engines whose manufacturer, during the design, made a margin that allows the cylinder block to be bored.

In lined cylinder blocks, the liners are pressed out and new ones are installed. Repair of internal combustion engines, for which the manufacturer did not provide for this, is carried out as follows: first, it is necessary to bore the cylinder, and then press in a cast-iron sleeve with a diameter for a standard piston for each compartment. If the cylinder block of the car engine being repaired is made of aluminum alloy and has a small wall thickness between the cylinders, then the cast-iron sleeve also strengthens the structure.

The surfaces of the block and head deformed during overheating are ground on the machine, while the gasket is selected in such a thickness that the degree of compression does not change.

Crankshaft and grinding

Damaged crankshaft beds of a car engine being repaired are restored by processing on a horizontal honing machine. At the same time, a very thin layer of metal is removed and a perfectly even axis of rotation is provided, which is a very important condition, since otherwise uneven loads will act on the shaft, which can lead to jamming or breakage and complete failure of the repaired internal combustion engine.

Troubleshooting of the crankshaft is carried out both by visual inspection and measurements, and with the help of various technical means. A rather interesting method for checking the crankshaft is magnetic flaw detection:

the crankshaft is mounted on two supports with windings of different polarities;
a special oil is applied to the surface;
after the crankshaft is sprinkled with metal powder.

The magnetic field that is created when current passes through the shaft makes it possible to detect hidden cracks in the shaft, since powder particles characteristically line up above them.

The detected shallow damages on the necks are eliminated by grinding the crankshaft, while the liners of the required sizes are selected for the repaired internal combustion engine. If there are no original repair parts, then they are replaced with non-original ones, and sometimes they are made independently to the required size.

When repairing a car engine, the bends of the crankshaft are corrected on special press equipment. With a large wear of the necks, a tape made of a high-strength alloy is welded onto them, after which the crankshaft is ground to fit the bearings. In the same way, the surfaces damaged from wear under the seals are restored. During the repair of the internal combustion engine, broken key connections are also subject to restoration.

The described method is not used for diesel crankshafts, because they work at higher loads that fall on the parts of the crank mechanism. You will have to buy a new crankshaft only if there are large cracks on it.

Piston group - piston replacement?

When overhauling a car engine, replacing pistons may not be necessary if the residual thickness of their walls and bottom allows for restoration. However, piston manufacturers do not provide repair dimensions and companies that specialize in repairing internal combustion engines can only rely on their personal experience.

On the piston bottom damaged from impact on the valve, counterbores are made. If it is not possible to find rings of a suitable size for the piston of a car engine being repaired, then grooves are slightly bored under them.

Without replacing the pistons, the connecting rods themselves are aligned on the press machine, and a new bushing is installed under the piston pin.

The cylinder head (cylinder head) is checked in the same way as the block itself - in a pressure bath. In order to expand hidden cracks, hot water is poured into it, after which all technological openings are closed and air is supplied under excess pressure to the cooling jacket. If there are cracks, air bubbles will be visible in the corresponding place.

The restoration of the cylinder head, as well as the cylinder block, is performed by welding. After that, the head of the block of the repaired internal combustion engine is again checked in the pressure bath.

Other possible technological operations during the overhaul of a car engine:

The valve guides are replaced with repair ones (if any) or made independently.
Excessively worn valve seats are bored out, and new ones are pressed in their place.
Bent camshafts are aligned on a press machine. As a rule, there are no cracks on them.
Beds, as in the cylinder block, are bored on a special machine. After that, metal strips are welded onto the bearing surfaces of the shafts and polished.

Repair technologies developed over a long period of time make it possible to restore almost any engine with damage of varying complexity. But do not forget that major repairs are not cheap, and before starting work, it is necessary to carry out economic calculations, because it will probably be much cheaper to purchase a new power unit.

One of the verdicts of service workers that drivers are so afraid to hear is “you will have to do a major overhaul of the engine.” This verdict is perceived normally when the car has already traveled a solid number of kilometers and its parts have worn out during long-term operation. And when they say this about a relatively “young” motor, then such a phrase sounds like a death sentence. First of all, because most drivers do not know what an engine overhaul is. Today we will talk in detail about this procedure for the cardinal "treatment" of the power unit.

An engine overhaul is a procedure that can be compared to dentures in humans. Just as a person at a certain age needs to install new jaws in order to properly and fully process food, so the engine needs to update components and parts so that it can “digest” fuel in a normal way, develop optimal power, in a word, fully function. There are several reasons that can lead to a major overhaul of the motor:

- “aging” of components and assemblies during long-term operation;

Non-compliance with the operating conditions of the engine (untimely, air and oil filters, refueling the car with poor quality, and so on);

The operation of the power unit at maximum loads in adverse conditions.

To understand that the engine of your car has already needed a major overhaul, you should pay attention to one of the signs that indicate serious malfunctions of the power plant. These include:

The knock of the engine, which appears when the liners and crankshaft journals, plain bearings located in the crank mechanism become unusable. This symptom can also be diagnosed by measuring the oil pressure. If it is low, there is wear on the specified parts;

Increased oil consumption and a bluish exhaust, which indicate the maximum wear of the elements of the cylinder-piston group;

Engine jamming, which occurs due to the destruction of the elements of the piston group, the crankshaft or the breakage of the connecting rod.

If one of the listed signs is observed, the driver should immediately contact the service station where his car is serviced and carry out a full diagnosis of the power unit. Based on the diagnostic data, specialists will determine the specific cause of the engine failure and carry out the necessary engine overhaul operations in this case. Of course, you can repair the engine yourself, but for this you need to have special knowledge and remember that only the owner of the car, and not the manufacturer or dealer who sold you the car, will be responsible for operations with the engine.

Now let's talk about what, in fact, is the overhaul of a car engine. First of all, the engine is removed from the engine compartment. For these purposes, the workshops have the necessary equipment with which you can disconnect all the power and cooling systems of the motor that control its electronics, unscrew it from the frame, remove attachments, lift and move it to a special machine (mounting slipway), on which the unit is cleaned from accumulated dirt, complete disassembly and washing of parts.

The first stage of a major overhaul is to determine the degree of wear of engine parts. The minder examines in detail the condition of the crankshaft, measures the diameters of the scuff marks on the necks. Then follows the procedure for measuring the beating of the journals, the flywheel with the crankshaft, and in the cylinder block - the axial play of the shaft. Also, a specialist, by measuring the diameters of the cylinders in the longitudinal and transverse planes at three levels, determines whether there is a deviation in their dimensions and geometry. The next measurement is to determine the size of the gaps between friction pairs (camshaft, valves and guide bushings, and so on). The cases of engine parts are also not left unattended, which are carefully inspected in search of cracks - pressure testing equipment helps in this. Having determined how worn out all the listed motor components are and comparing the values \u200b\u200bresulted as a result of diagnostics with normal ones, specialists determine which overhaul operations should be carried out. As a rule, it is necessary to repair such engine components as the cylinder block, cylinder head, crankshaft. Let's consider them separately.

Cylinder block repair operations include replacement of removable liners, boring and honing of cylinders. There are engines in which removable sleeves are not provided, in which case the mechanic installs the so-called repair sleeve. To do this, he bores a cylinder on the machine, and inserts a repair sleeve into the resulting slot, then processes it to obtain a size similar to other cylinders. The honing procedure is the application of strips with a certain profile to the surface of the cylinder, which help to retain oil there, which allows better lubrication of the piston rings and piston skirts. The cylinder is processed to the so-called repair size, so that it corresponds to the diameter of the repair piston, while taking into account the value of the thermal gap (the value between the piston skirt and the cylinder wall). Also, the repair of the cylinder block includes such operations as restoring the crankshaft bed, eliminating cracks in the block itself, milling the mating plane before its subsequent alignment.

If you have to repair the cylinder head, then locksmiths carry out many small and labor-intensive operations here. They consist in welding cracks, replacing valve guides (if the degree of wear of the guides is not critical, they are restored by making the diameter of the hole for the valve stem smaller) and valve seat chamfers. In addition, the repair of the cylinder head involves the restoration (replacement) of valves, the replacement of the camshaft and pushers, the restoration of the deformed mating plane by grinding, and another mandatory operation is the installation of new valve stem seals.

Another time-consuming operation carried out during the overhaul of the motor is the restoration of the crankshaft to optimal working condition. It is carried out as follows: the washed and dried parts of the connecting rod and main journals are first ground and then polished, achieving alignment of the peaks of the surface relief of the journals and the edges of the oil channel holes. Also, the complex of work on the repair of the crankshaft includes its editing and diagnostics of the surface, which is usually deformed during prolonged beating of the necks.

When these engine components are repaired, they are cleaned of the formed chips (pay special attention to the lubrication and cooling channels), washed, and then blown with air and dried. After drying, the process of assembling the elements of the power unit begins, which is carried out on the assembly slipway, observing and controlling all the gaps in the friction pairs. When the engine elements are installed, it is necessary to weigh the pistons, piston pins and connecting rods, adjust all clearances and check the tension of all belts (chains).

The tightening of the bolts fastening the body parts of the engine must be carried out sequentially in order to prevent misalignment and subsequent deformation of the newly repaired elements. Before installing the assembled engine in the engine compartment, minders check the operation of the shafts with their hands, making sure that they rotate effortlessly. If a hitch occurs, it means that something is installed incorrectly, and, therefore, you will have to disassemble the element and again measure and re-install.

One of the important stages of the overhaul of a car engine is its cold break-in. That is, even before installing the engine in the engine compartment and connecting all the “feeding” systems (fuel, cooling, and so on) to it, you need to pour oil and coolant into the unit, connect the electric motor and arrange the so-called crankshaft run. Cold break-in is needed so that friction pairs and replaced (refurbished) engine parts run in under light load. Sometimes minders carry out a cold run-in of a motor already installed in the engine compartment, letting it idle for some time (up to 4 hours).

Finally, the final stage of the overhaul of the engine is the adjustment of the engine, which is carried out both on a special stand and directly on the car. At this stage, minders check the coherence of the work of the cylinder-piston group, the crank mechanism, fuel and other engine systems.

Remember that the overhaul of the power unit of the car allows you to increase its service life and increase the motor resource, which, of course, will affect the quality of the engine and the general condition of the car. Therefore, do not ignore the above signs, which are eloquent evidence of an impending breakdown of the power plant, and take preventive and preventive procedures in a timely manner. Let the overhaul be a long and costly business, but the “health” of your “iron horse” is definitely worth it.

The car engine does not last forever. Consider the question: how to determine the condition of the engine before the overhaul, what is needed for this, what are the terms and guarantee for the repair of the motor.

How to determine the condition of the engine?

The degree of wear of the motor and the cylinder-piston group, in particular, is assessed by measuring compression and residual vacuum, as well as by other technical diagnostic methods (using an endoscope, a motor tester). But there is an indirect indicator - oil consumption. The limit for the engine of a modern car is considered to be the consumption of 1 liter per 1000 kilometers. If more, then there is wear inside the motor.

The mileage of the engine before overhaul varies for different machines within a fairly wide range and depends on the durability of the structure and operating conditions. For many domestic cars, the mileage to the "capital" is on average 150-180 thousand kilometers, the majority of foreign cars - 200 thousand. For example, a BMW engine can run up to 180,000 km before overhaul, Ford - 200,000 km, and many Japanese manufacturers - up to 250,000 km.

What is meant by car mileage before overhaul? This is the mileage above which irreversible consequences occur in the engine in the form of destruction of its parts. For example, gaps appear on the cylinder walls, other parts wear out. After that, the operation of the motor without further repair is impossible. By the way, you can find out the condition of the motor by analyzing the engine oil. If there are metal particles in it and their number increases with mileage, then there is a lot of wear.

The quality and timeliness of maintenance affects the life of the engine. The use of non-original motor oils and bad filters can reduce the resource by dozens of times. In such cases, it is necessary to overhaul the engine even on a new car.

Spare parts selection

The quality of spare parts must be guaranteed Otherwise, all your efforts, time and money will be wasted. It is equally important that the repair does not turn out to be selective: all worn parts and assemblies must be put in order so that later they do not limit the life and reliability of the engine.

As practice shows, domestic motors have their own specifics, and many foreign ones have their own. In stores and markets, you can buy everything for our engines - from the cylinder block to the last bolt and at affordable prices. Unfortunately, the quality of these details can be missed: domestic products sometimes turn out to be outright marriage, and imported ones are a fake for one or another famous company. Therefore, it is not worth making a purchase without experience, it is better to leave this matter to those who will repair the engine.

By the way, respectable workshops never require customers to search for spare parts on their own - they have reliable and trusted suppliers.

With the repair of parts is more difficult: it is not so easy to find a place where machine repairs of the crankshaft or cylinder block will be done with high quality. Lack of special tools and fixtures. There is little literature on repairs, and they don’t read it very much: most craftsmen boil in their own juice, achieving results through trial and error.

What are the deadlines

Do not forget that the overhaul of the motor is one of the most difficult and is not done quickly. Therefore, when choosing a workshop for engine restoration, you should not look for where the repair period is minimal. Some indicative dates are given in the table.

What is the guarantee

When choosing a service station, you should not miss the issue of warranty. Almost everyone gives a guarantee for the work performed, but not everyone correctly understands what it is. A modern engine is a complex mechanical unit with a large number of parts. No matter how well it is repaired, there is always the possibility that some defect will be discovered later.

There is an optimal warranty period. A repaired engine in the initial period of operation is most prone to breakdowns, but after a run of 10-15 thousand km, their probability becomes insignificant. Many service stations define a guarantee with a mileage of 20-40 thousand km, considering that the engine's service life is incomparably longer.

At the same time, both the nodes inside the block and in the cylinder head are subjected to significant mechanical and thermal loads during engine operation.

It is not surprising that damage to the cylinder block will not only disrupt performance, but also disable the power unit. For this reason, the restoration of the unit and its repair must be carried out efficiently and in a timely manner.

Read in this article

The main defects and malfunctions of the engine block

To begin with, there are two types of cylinder blocks:

cast iron BCs;
aluminum alloy blocks;

As a rule, cast iron blocks are additionally strengthened with graphite, and lightweight aluminum products are made sleeved (a cast iron sleeve is inserted into the block). There are also aluminum cylinder blocks without liners. The composition of the alloy includes silicon, which significantly strengthens the block.

As for the sleeved blocks, the sleeves are "wet" and "dry". In the first case, the coolant is in direct contact with the liner, while in the second case, the liner is tightly pressed into the body of the block during manufacture.

One way or another, each solution has its pros and cons, and during operation, various damages and defects of the cylinder block or defects in the block liners occur (depending on the type of BC).

Repair of the cylinder block must begin with establishing the cause of malfunctions and troubleshooting. Often the main problem on engines with high mileage is the wear of the surface of the cylinder or liner. Scuffs appear on the surface (mirror) of the cylinder, cracks, shells, etc. may form.

Less often, the cause of block defects is the unexpected destruction of piston rings and other unforeseen breakdowns. We also add that deformation of the bed of crankshaft bearings, etc. often occurs in the BC.

With regard to wear of the cylinder surfaces, in this case, such wear is often "natural", that is, the result of operating the engine in normal operating conditions. The repair of cylinders in this case often involves boring and honing the cylinder (applying honing). This allows you to remove the ellipse of the cylinder, remove scratches and scuffs on the mirror.
A more difficult case can be considered a broken connecting rod,
since the damage is usually more severe. Also, the cause of block defects is breakage, destruction of the valve seat, etc. The result is scuffing on the cylinder surface and other damage. Also in the list of frequent malfunctions, sleeves should be highlighted.
We also add that there are so-called “hidden” problems, that is, it can be difficult to determine defects visually within the framework of a superficial examination. At the same time, unskilled repairs, which are limited to the banal replacement of worn parts, will still lead to the fact that the engine will need to be disassembled again after several hundred or thousand kilometers.

These "hidden" defects, first of all, include the deformation of the cylinder block. Often such a deformation is a consequence of a violation of technology in the process of manufacturing a block. In simple words, if the internal stress is not removed in the block, deformation will occur.

By the way, this problem is more inherent in cast iron blocks. Also, the deformation of the block (both cast iron and aluminum) can be caused by overheating of the engine or its uneven heating during operation.

Restoration of engine cylinders

So, the repair of the cylinder block and the restoration of the cylinders themselves involves:

thorough cleaning of BC surfaces;
then produced (cooling jacket);
the oil channels are also washed and cleaned, and then the oil channels are checked;
further carried out;
then the block is bored/sleeved, surfaces are ground, etc.

For many engines, cylinder boring is a mandatory procedure within. To perform the procedure, a special machine for boring engine cylinders is used. Under the very boring of the block, one should understand the processing of the inner surface.

Such processing is actually the removal of a layer of metal to smooth out bumps, remove scuffs, smooth out pits, etc. The main task of processing is to give the cylinders a normal shape (cylindrical).

The next step after boring is. The application of honing to the inner surfaces of the cylinders is carried out with an abrasive fine-grained material (honing stone on the honing head). The honing head itself is attached to the spindle of the honing machine. Such a machine allows you to implement rotational and reciprocating movements.

Another repair of the cylinder block may involve a sleeve or re-sleeve. In the first case, the installation of sleeves should be understood, although the factory design does not initially imply this. In the second, the worn sleeve is removed from the block, after which a repair new one is installed.

As a rule, the sleeve of the block can be made in two ways, when the sleeve is cooled with liquid nitrogen, or the mating part is heated. In the first case, the cooled sleeve is reduced in size and easily placed (pressed) into the seat. The second method involves heating. Both methods of pressing sleeves allow you to achieve the desired tightness.

Finally, we note that also as part of the restoration of the block, it may be necessary to repair the bed of the crankshaft bearings. Also, in some cases, it becomes necessary to eliminate the deformation of the block. For this, the method of artificial aging is used, when the block is heated to a certain temperature, after which various sections are processed.

What is the result

As you can see, there are quite a few malfunctions of the cylinder block itself. Some may be considered minor (e.g., etc.), while others are quite serious (e.g. cylinder wall wear, cracks, etc.)

It is important to understand that in each case the technology for repairing the cylinder block may differ. Also, the complexity of repairing an engine block will directly depend on the problem itself, on the general condition of the damaged part, on design features, etc.

In practice, this means that in some cases it is possible to restore the cylinder block with your own hands even in a garage, while in others it will be necessary to have special equipment (machines for block boring, honing, grinding). Also a very important aspect is the experience and qualifications of the master himself.

In view of the foregoing, it becomes clear that only experienced specialists should be trusted to perform such work, and the engine itself should be optimally repaired at such service stations, where it is possible to perform all the necessary operations right on the spot. First of all, this will reduce the repair time, and can also often serve as a guarantee of quality.

When does an engine need a major overhaul?

You drove, you drove - suddenly the engine of your favorite iron horse rattled. So do not rush to immediately grab onto the "capital". We need to check everything first.

First, let's immediately determine that this is not a bulkhead of the engine, when it was disassembled, cleaned, gaskets changed and assembled. There are more serious reasons here. So let's take a look at the prerequisites:

How old is the car? How far has she run? Foreign or domestic? If the car is more than 10 years old, it is domestic, for example, a Zhiguli or Moskvich, then its limit is 150 thousand kilometers. For a foreign car - up to 300. Perhaps the resource of your car has been exhausted, and for this reason the power has decreased.
Let's see what's up with the oil. Yeah, the pressure has dropped again, despite the fact that the car bursts oil godlessly - another reason for repairs.
We check the compression, because this is the main parameter that affects the choice - whether or not a major overhaul is needed. We take a compression meter from friends, we take measurements. For example, in our case, out of four indicators, one has five instead of eight, which means that it’s definitely time for a major overhaul.

Where to begin?

Of course, with information. We get a manual in which it is reported in detail and with diagrams how to repair your brand of car. We find a catalog on the Internet that contains spare parts for this car in order to immediately determine the prices and, possibly, place an order in an online store.

Cooking tools:

keys - ratchet, torque;
mandrels for coupling pistons, caps;
rassuharivatel to valves;
micrometer;
heads;
valve adjuster;
two-arm or three-arm puller;
stethoscope;
tweezers;
support stand;
hydraulic chain hoist;
puller kit.

Getting to the engine

We drive the car into the garage. We remove the battery. Detach the hood so that it does not interfere.

Carefully drain all liquids: antifreeze, oil. To do this, instead of bolts on the radiator and cylinder block, we install faucets - they are sold at any auto shop - and drain them using hoses into the prepared container.

Given the age of the machine, we very carefully disconnect the wiring, connectors, pipes, hoses, etc., so that they do not crumble in our hands, nothing is damaged or broken. And then some craftsmen then still repair wiring, cooling system.

We remove without haste everything that can interfere with getting the engine: air filter, carburetor, gasoline pump - do not forget to wind the bolt, oil separator, distributor, cylinder block cover, camshaft, cylinder head studs, and then the head block, crankcase protection, generator with belt, fan, radiator. We unscrew the bolts that secure the engine. Now the engine can be removed.

Stages of engine overhaul on the example of the Zhiguli brand

Step #1

Before you get to the innards of the engine and start doing a major overhaul, try to safely remove it from the car. Call an assistant - one cannot manage here.

Prepare four tires by stacking them on top of each other. Place two wooden blocks on top. Then lay the engine on them.

Step #2

Now fix the talc, i.e. the lift, on the ceiling beam, it can be attached to the tripod, placed above the hood.

Do you know how much the engine weighs? How do you like an aggregate of 140 kilograms? Serious thing? It is clear that you can’t lift it with your hands, and if it falls down, you can’t do without injury. To prevent this from happening, be extremely careful, check the fastening of the talc, and only after that start lifting.

Step #3

Gently, without too much fuss, pull the engine up, bring it to the stack of tires that have already been laid out in front of the car, lower it, turn it over so that the crankcase is on top, on wooden blocks.

When disassembling, remember or mark somewhere where you are shooting from and where the part was originally located, so that later you don’t have extra ones, like some homemade ones.

Start gutting the flywheel: first remove the clutch, then get to the boot of the crankcase. Move on to the oil filter. Having unscrewed the fasteners, remove the bolts and remove the crankcase, being careful not to break the oil intake.

Step #4

Now remove the front and rear covers of the unit along with the stuffing box. Take care of the piglet's star, remove it using a puller. Go to the chain stop and unscrew, remove the tensioner shoe, and then the chain, crankshaft sprocket.

Move on to the crankshaft. Remove the nuts from the connecting rod caps, then the caps, carefully pull out the pistons, remove the liners, carefully inspect them for reuse. If you can no longer use them, take a sample and buy new ones at a specialized store or car market. Just first decide if you need a groove for the necks, and only then fit the liners under them. Get the crankshaft with persistent half rings.

Step #5

Remove the pig, the oil pump and its drive gear. Turn over, putting it sideways, remove the pistons with connecting rods from the cylinders. Buy a new piston system according to the old model. You still need to go to the auto repair shop.

Take new pistons, let them bore the block under them, and also grind the crankshaft and press in the piston pins. Measure the crankshaft journals with a micrometer, look in the manual for what size liners should have, buy them. If you choose the liners correctly, you can rotate the crankshaft by hand This will be the fit test.

Step #6

Start assembly by removing carbon deposits. Remove all metal shavings, wash the beds, lubricate them and liners with engine oil, install in place, guided by the manual. On the rear wall of the block, place the thrust half rings so that the recesses are turned on the plane of the crankshaft.

Now you can return the crankshaft with liners and covers to its place, checking the markings according to the manual, the places where the locks are located. Make sure they are all on the same side. Take a torque wrench, tighten the bolts, turn the crankshaft - if it turns easily, then everything is in order. Otherwise, replace the earbuds with thinner ones.

Step #7

Ask the workshop to assemble the piston, because you yourself will not be able to heat the connecting rod heads to more than 100 degrees, but you need to heat them up to over 200. Check the process.

Now carefully smear the piston pins through the holes, throw in the piston rings without haste, make sure that the slots and holes are preserved, tighten the mandrel with a key. Lay the block on its side, insert the piston with the connecting rod, not forgetting the markings.

Step #8

Take a wooden block and, gently knocking, push the piston into the cylinder. Turn the block back to its original position, but do it so that the crankshaft is at the top. Tighten the bolts.

Gently begin to pull the connecting rods to the necks. Then scroll the crankshaft to make sure that everything is set correctly and the liners do not need to be changed. Now you can tighten the bolts.

Step #9

Put a new oil seal on the cover, install it on the block, pre-lubricate the joints with sealant. Proceed to install the clutch boot and flywheel. Remember that the flywheel must be turned to the fourth knee of the crankshaft with a groove - this is important.

Now start installing the sprocket, pig, tensioner shoe, front oil seal, oil pump, flywheel clutch.

Step #10

You can finally install the engine and bolt it on. Tighten carefully so as not to strip the threads and do not burst parts. Return the pump, generator, radiator, fuel pump to their original places, attach wires, hoses, terminals, check the fastening strength.

Cold running

Once the overhaul of the engine is completed, it is imperative to carry out a cold break-in before installing it on the machine. This is done so that the new parts get used to each other, and is carried out in a passive, bench mode. or in hard towing, when due to the movement of the wheels the crankshaft begins to spin and a cold break-in occurs.

So, in the garage, connect the air filter hoses, cooling systems, oil supply, exhaust to the engine. Install plugs. Connect the unit to the electric motor.

Fill in the coolant that was drained during disassembly, heating it to 85 degrees, then oil heated to 80 degrees. At low speeds, from 600 to 1000, let the engine run for 2 minutes, at high speeds, from 1200 to 1400, for 5 minutes.

Tips for operating the engine after a major overhaul

Before the car runs two and a half thousand kilometers, do not accelerate sharply, pick up speed gradually, do not overload the engine.
After the first run, drain the oil, replacing it with a clean one, but of the same brand (preferably).

Now you are convinced that a do-it-yourself engine overhaul is possible and profitable, because it costs three times less. In addition, it will allow you to operate the car for several more years as a result of extending the service life, prevent unexpected breakdowns on the road, and help avoid an accident.

The following video will tell you about what spare parts are needed for the overhaul of the VAZ 2103 engine:

Take it, tell your friends!