Replacing the cylinder block: instructions and recommendations

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Probably, any motorist would like to learn how to repair his car on his own. Doing repairs with your own hands, you can not only gain the necessary experience, but also save a lot. Let's learn and find out how to replace the cylinder block on gasoline engines. This type of repair seems complicated, but there is nothing supernatural here.

When is the engine block replaced?

Specialists who have been repairing engines for years share with beginners the possible reasons for replacing the block. Before changing the block, it is necessary to carry out a thorough troubleshooting of the part. Critical defects include cracks, crooked mating surfaces, curvature after tightening, damage to the cylinder walls, damaged threads and leaking plugs.

Cracks in the block

If there are cracks between the cooling jacket in the engine and the oil channels, then this is the most serious defect that can only be encountered. If a used engine is chosen to replace the cylinder blockpart, it must also be carefully examined for deformations.

Even slight micro cracks will cause the coolant to mix with the oil. Damage between the jackets of the cooling system and the walls of the cylinders will necessarily lead to the appearance of antifreeze in the combustion chamber.

Microcracks can form from overheating, as well as due to casting defects. The cast block may have pits and other defects. In the case of the cylinder head, this is also a replacement for the VAZ cylinder head.

Ways to find a crack

You can identify a crack by the following symptoms. These are fluctuations in engine temperature in the summer - the arrow of the temperature sensor jumps in the direction of increase or decrease. You can also determine that the block is cracked by the characteristic tripping under load (for example, when climbing uphill).

But not in all cases it is possible to detect a crack with the naked eye. Often the crack is so small that it is detected using pneumatic pressure testing, ultrasonic scanning, the use of magnetically sensitive equipment and hydro testing.

If there is no special equipment, then the service station uses the diagnostic method with water and air. The bottom line is that water is pumped into the cylinder block. If it leaks out, then there is a crack.

Curved plane

This defect occurs due to low-quality coolants. But even if only expensive high-quality antifreeze is poured into the expansion tank, idealplane will not work. If a used block is selected, then the degree of deformation must necessarily be within tolerance. Then, after grinding or milling, the engine size will not decrease and the compression ratio will not increase.

To find out whether the plane is curved or not, it is necessary to take measurements using high-precision measuring instruments. If the curvature is within the manufacturer's tolerances, then the block can still be used. Otherwise, the cylinder block is replaced.

Cylinder damage

This is another reason why they decide to replace the block. Among the reasons are scuffing, natural wear, development in the form of a taper, ovality. If the burrs are not deep, they can be removed with a repair bore.

Checking the block at home

Alas, even in a well-equipped garage, it is very difficult to check the cylinder block. To give an accurate conclusion, it is necessary to carry out a pressure test. All openings of the cooling system are jammed in the block. Next, the part is placed in a container with warm liquid. The tightness is checked by introducing pressurized air into the channel of the cooling jacket.

You can check the evenness of the mating plane using a special ruler and probes. It is not worth determining the presence of deformation by eye - tolerances are measured in hundredths of a millimeter.

Cylinders are defective with the help of an inside gauge. It is a measuring device for precisemeasurement of hole diameters. It is necessary to measure in the middle of the piston stroke, at the beginning of the stroke, in the places where the piston is shifted to bottom dead center and top dead center.

Required tool

So, the block is beyond repair, and the cylinder block needs to be replaced. This will require a large number of tools. You will definitely need a set of socket heads and wrenches, a mandrel for installing pistons in the block. You will also need a torque wrench, a set of gaskets and bolts for mounting the cylinder head.

How to disassemble the engine - in general terms

In fact, there is nothing complicated in the process of work. The whole process comes down to removing all attachments, all internal parts, elements from the block and then assembling it all on a new block.

First of all, you need to disconnect all the wires from the engine, remove the electronics, the air filter and its housing. In the end, only the power unit itself will remain. You also need to unscrew and dismantle everything that may interfere in the future.

Next, you can disconnect the gearbox. This operation will not cause difficulties for anyone, since the gearbox is fastened with bolts. Sometimes it's easier to remove the box after the engine is removed from the car. But in this case, after replacing the engine block, there may be problems mounting the motor back.

Next remove the clutch. Here, too, everything is relatively simple. The bolts holding the clutch basket are loosened, and then the entire assembly is easily and conveniently removed from the flywheel.

Next dismantleddrive pulley on the crankshaft. To perform this operation, you need a flat screwdriver, as well as a suitable wrench size. A gas wrench may also be useful. First of all, the crankshaft is fixed - this is done by blocking the flywheel with a screwdriver. Then the pulley nut is unscrewed with a wrench.

Then the bolts holding the flywheel are loosened and the part is removed. A plate is usually installed under the flywheel - it should also be removed. Next, a belt or chain is removed from the motor camshaft. But this must be done if the head of the block has not yet been removed.

Then the camshaft is dismantled, but sometimes it is easier to remove the entire cylinder head completely. The cylinder head is secured with stud bolts or nuts. It is better to purchase studs or bolts with new ones in the kit if the VAZ cylinder head is to be replaced.

At this stage, you can turn the motor over and remove the pan. There is a gasket under the oil pan and it will need to be replaced. But in some cases, it is possible to get by with a sealant-gasket.

Next remove the oil pump. To do this, unscrew the cover of the rear oil seal, dismantle the pump shaft and drive gear. Unscrew the bolts and remove the fixing bracket, then carefully remove the shaft and gear with a screwdriver. This gear is very important for the operation of the engine. Therefore, when replacing the VAZ-2110 cylinder block, you need to be very careful with it.

Next, dismantle the parts in the mechanism of the connecting rods and the crankshaft. It also requires care and attention. Parts, although they seem the same, are not interchangeable. Each piece is unique.

In the beginningremove the rods. The crankshaft is rotated so that the two connecting rods are in their upper position. Then the nuts are unscrewed from the connecting rod cover and the yoke is removed. Sometimes you will have to lightly tap on the cover with a hammer - on the sides of the part. Next, the connecting rod is removed completely along with the piston - it can come out by hand or with a hammer.

Next, remove the root caps. They are fixed with nuts, and each cover must have its own place on the new block. Then the crankshaft is taken out, the liners and retaining half rings are removed. On this, the process of disassembling the engine and cylinder block can be considered completed. You can install a new block and assemble the motor.

Assembly Features

Assembly is carried out in the reverse order. When installing connecting rods, it must be taken into account that each of them has marks made by the manufacturer. They are also on the block - the marks on the block and connecting rods must match.

When installing, observe the left and right sides. The connecting rod and its cap are perfectly matched at the factory - a pair of individual. They cannot be replaced. To install the piston in the cylinder, you will need a special mandrel to compress the piston rings. The mandrel can be purchased ready-made or you can make it yourself. Connecting rod and main bearings are mounted in such a way that the locks on the bearings and seats match. The bushings are lubricated with oil before installation.

About changing plugs

Sometimes oil or coolant leaks from the engine block. The blame is most oftenplugs. Due to corrosion, holes appear on them. There is no point in repairing them, only replacing the plug of the VAZ cylinder block will help.

In order to facilitate the process, remove all nodes that interfere. Disconnect the muffler pipe from the manifold, remove the bracket for the coolant pump pipe, disconnect the crankcase ventilation hoses from the carburetor and cylinder head. Remove the air filter, carburetor hoses, timing cover. Next, remove the belt and pulley itself. Then the cylinder head is dismantled.

Next, to replace the plug of the VAZ cylinder block, use a chisel and a hammer to turn the plug in the block body. The part can be easily removed with pliers. Otherwise, the part is drilled out. Emery clean the edges of the hole. Before installing a new plug, you can treat the seat with sealant. The part is pressed in with a hammer. Then everything is assembled in the reverse order.

After removing the cylinder head, it is worth replacing the cylinder block gasket. This is a must as the pads are disposable. In some cases, a sealant gasket may be used.

cylinder head

Often, after troubleshooting the engine, it turns out that there is no need to change the entire block and you can get by with just replacing the cylinder head. Change the element due to overheating. Even due to slight overheating, a crack can form on the working surface of the part, in the steel liners, between the valve seats. The head is also removed to replace the engine cylinder head gasket.

For dismantling you needremove everything that can interfere - this is the battery and ignition wires. Next, it is better to take a marker, mark all pipelines, hoses and remove them. Then all attachments are removed.

After that, remove the head cover, belt. It is recommended to unscrew the bolts very carefully, using the reverse tightening scheme. When the head is removed, various repairs can be carried out on it (for example, replacing the cylinder head valve). The head is mounted in the reverse order. But at the same time, a new gasket and a new set of bolts are installed. You need to tighten the latter with the help of a torque wrench with the required force.

Conclusion

All engines are built approximately the same, and with the help of this instruction, a novice car mechanic will be able to disassemble the motor and replace the block. But it is imperative to take into account the features of each engine, even if it is a replacement for a cylinder block gasket on a VAZ. And then everything will definitely work out.