A terrible dream of a motorist: engine overhaul

If the car owner has been operating his car for a long time and is not going to part with it in the near future, then replacing the engine with a contract engine or its overhaul is an inevitability that will have to be put up with. After the end of this lengthy procedure, the motor, in its characteristics, will approach the factory state (provided that professionals in a reputable car service were engaged in the restoration of the power unit). The overhaul includes putting in order the block, cylinder head, crankshaft, cooling and lubrication systems, crank mechanism.

Signs of an impending "capital"

Do not confuse it with the so-called. engine overhaul, when only those parts that are out of order are changed (for example, piston rings, valves, valve stem seals, etc.). Overhaul of the power unit involves the diagnosis and restoration of all its important components, regardless of the degree of wear. Symptoms:

• ? The appearance of a knock in the cylinder block (BC) intensifying with a set of revolutions
  
• ? Drop in oil pressure, accompanied by the ignition of an emergency lamp on the instrument panel
  
• ? Dark blue shade of exhaust gases
  
• ? Compression reduction measured by a special device
  
• ? High oil consumption - a liter or more per 1000 km
  

The main reason for these problems is the high mileage of the car and the natural wear of components and parts. However, severe vehicle operating conditions, untimely and (or) careless maintenance, the use of technical fluids not recommended (poor quality) by the manufacturer, and aggressive driving style can bring overhaul closer.

The main stages of overhaul

First, the engine is dismantled and completely disassembled. Each node, detail is cleaned, washed, so that defects are easier to notice. At the second stage, the nodes are diagnosed by determining the degree of their wear. check the head, then the block itself. Next, they look for visible defects: for example, cracks in the BC, scuffs (using an endoscope), they measure the geometry of rubbing parts.

Head restoration

Repair may be needed if, due to overheating, coolant went into the oil pan and replacing the gasket did not help. A large consumption of lubricant may be associated with breakage, wear of valve stem seals. There are frequent cases (mainly due to low-quality fuel) of valve burnout. Cracks in the cylinder head may appear due to frozen water in the cooling system.



First, the head is dismantled and then disassembled: the valves are removed, having previously dried them with a special device. Inspect them, clean them of carbon deposits and, if cracks and potholes are found, replace them. If the valve seats have worn out, new ones must be installed. The same can be said about the bushings inside which the valve stems go.

BC repair

The most common way to process it is boring. To do this, use a special machine, with which a layer of metal is removed from the inner surface of the cylinders. As a result, they take on a regular form, scuffs, scratches, etc. defects are removed.

Honing

It is a procedure for giving the cylinders the required diameter and applying a rough mesh to their walls, which is necessary to retain a certain amount of lubricant. This makes the grinding of parts faster and lubrication more effective. The treatment is carried out with a fine-grained abrasive, performing rotational and translational movements.

How to eliminate cracks in the BC

They appear when water freezes in the cooling system, pouring liquid into an overheated engine, and unprofessional repairs. Due to cracks, the power of the power plant drops, antifreeze leaks. Colored water is used to detect defects. It is poured under pressure into cylinders (up to 25 atm.), Water jacket (up to 3 atm.) and left for a couple of hours. The coloring matter that has come through will indicate cracks. To eliminate them, argon welding is used. But there are also easier ways.

nailing

This is the installation of copper rods at the ends of the crack so that it does not diverge further. Then holes are drilled in the block, threads are made in them. A metal patch is applied, lubricated with red lead, a lead gasket is placed under it and the “pie” is attracted with screws.

Gluing and filling

The first option is suitable for small cracks. The problem area is cleaned, degreased and a suitable compound (for example, epoxy resin) is introduced. If the cracks are microscopic in size (they are called "hairy"), they can be filled with a solution of ammonia and hydrochloric acid. The defect will be covered with oxide.

Estimated cost of overhaul of the Lada Granta engine

In the workshop you will be offered a price list, which will indicate the cost of any operation related to the replacement, repair of a particular unit, node. Initially, it is worth conducting a thorough diagnosis. For example, if you have an increased consumption of lubricant, and the compression is normal, the reason may lie in bad valve stem seals. They are replaced directly on the car without removing the cylinder head. But if it has to be repaired, then the procedure for "Grants" will cost 3-4 thousand rubles. for eight and 6-8 thousand rubles. for a sixteen-valve assembly. Restoration of the cylinder block (only work) will cost 12-13 thousand rubles. Crankshaft grinding - 1800 rubles. If you add here the cost of gaskets, oil seals, filters, oil, etc., the total price will look like this:

• ✅ Performance of work on the restoration of the BC, cylinder head, crankshaft (all together) - 17-18 thousand rubles.
  
• ✅ The cost of spare parts is 10-11 thousand rubles.
  
• ✅ Total - from 27 thousand rubles. up to 29 thousand rubles
  

Engines for foreign cars: overhaul or contract unit

If we take the cost of restoration, for example, of a Hyundai Solaris engine, we get a sum from 35 to 60 thousand rubles. Add the costs of the spare parts themselves, consumables (oil, antifreeze) and a major overhaul will result in a tidy sum, reaching a third of the total cost. car. In addition, the cylinder walls of the unit are thin and there are no repair sizes. That is, simply replacing the pistons, rings and boring the crankshaft will not always help. The question arises: maybe it is easier to buy a contract unit? If you search well, including on the Internet, you will find an engine for 55 thousand rubles. (G4FG 1.6, mileage 60 thousand km), there are 60, 70 and 90 thousand rubles. It all depends on the year of manufacture and mileage of the car. As a result, you will save time, and ultimately money. If, for example, you do not have good friends in auto service centers engaged in major repairs of power units.



Buying a contract engine is more profitable than a major overhaul. The opinions of car owners on this topic are ambiguous, however, there is a demand for such units, and it is stable. The main recommendation is to purchase an engine from a well-trusted supplier. As a last resort, give preference to units that were not operated in the countries of the former Union.