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Engine overhaul: frequency, stages and features of work
Engine overhaul: frequency, stages and features of work

Engine overhaul is a process during which the engine and the main units of the power system are brought to the factory state.

The overhaul of the internal combustion engine involves disassembling and cleaning the engine, diagnosing components for defects and replacing them if necessary, repairing the crankshaft, cooling systems, lubrication and fuel supply, cylinder block and crank mechanism.

Overhaul and overhaul of the power unit are different procedures. Bulkhead means disassembly and assembly of the engine, replacement of failed elements. Reasons for overhaul include loss of power and low compression due to natural wear of parts.

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Reasons for overhaul: untimely oil change

Untimely replacement of engine oil and oil filter provokes increased friction of parts and mechanisms, which can lead to acceleratedwear of the power unit and the need for major repairs.

Decrease in the basic quality characteristics of engine oil and the appearance of deposits in the channels and on parts provokes increased wear and an increase in frictional forces.

Poor quality motor oil

The use of low-quality engine oil can accelerate engine wear. Such oils do not contain the necessary components, which leads to an increase in the amount of tarry deposits.

All this can cause strobing of the channels through which the oil mixture passes, oil starvation of the engine and rapid wear of its mechanisms, which can cause scoring and jamming.


Dirty air and fuel filters, loose intake system connections that allow dust and dirt to enter the engine can also accelerate the wear of the power unit, primarily cylinders and pistons.

engine disassembly and assembly

Minor damage

Untimely elimination of defects and malfunctions can also accelerate engine wear. Incorrect adjustment of valves and other elements of the power unit can also lead to an overhaul of the internal combustion engine. A knocking camshaft, for example, is a major source of contamination in the lubrication system.

Engine pistons and combustion chamber surfaces are destroyed by the following factors:

  • Incorrect ignition timing.
  • Inaccurate operation of the fuel injection system.
  • Faulty systemengine control.
  • Incorrect spark plugs for specific vehicle model.

The above factors can cause the engine to stall on the move and not start, detonation occurred in the ignition system, or failure of the combustion chambers and pistons. Overheating of the engine, provoked by breakdowns in the cooling system, can cause deformation of the cylinder heads.

The oil film that forms on frictional engine parts loses its strength with insufficient cooling, which leads to rapid wear of parts and the appearance of piston burnouts and other malfunctions in the fuel equipment.

spare parts for engine overhaul

Features of operation

The mode in which the car is operated also affects the condition of the engine. The working life of the machine is reduced by 30% if the engine regularly operates at high speeds and at maximum loads. You can avoid a situation where the engine stalls while driving and will not start, and similar situations, by adhering to a moderate driving style.

Incorrect starting of the motor in 70% of cases is the cause of such a malfunction. This leads to wear of the engine heads. Especially dangerous is a cold start, which is carried out when the temperature and viscosity of the engine oil do not meet the standards and specifications.

Deposits can build up in the powertrain lubrication system during short winter trips, leading to corrosion of cylinders and piston rings.

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When it is necessary to overhaul the internal combustion engine

The appearance of certain signs in the operation of the engine signals the need for a major overhaul:

  • Spark plug fouling.
  • Increased fuel and engine oil consumption;
  • The flow of gases and steam leaving the ventilation system pulsates noticeably.
  • Smoke from the exhaust pipe of different shades. Professionals can determine the cause of engine failure (cylinder heads, power system, etc.) by the shade of the exhaust.
  • Decrease in engine power, as evidenced by a drop in maximum speed by 15% or more, an increase in vehicle acceleration time to 100 km/h.
  • Uneven engine idling.
  • Interruptions in the operation of the motor, its overheating, detonation, early or glow ignition.
  • The appearance of third-party sounds in the muffler or carburetor.
  • Low oil supply pressure.
  • Third-party noises and knocks in the engine.

Overhaul of the engine is carried out when such symptoms appear, but it is worth considering the fact that a complex of similar problems signals serious problems.

In practice, it turns out that the overhaul of the internal combustion engine is required after 100-200 thousand kilometers.

engine head

Stages of overhaul

Motor overhaul is carried out in several steps:

  • Removal, disassembly and assembly of the engine, cleaning of all parts and assemblies;
  • Diagnosis of components, determining their degree of wear.
  • Troubleshooting: engine block cracks, gap measurement, crankshaft troubleshooting, measurement of geometry of friction parts and comparison of their dimensions with factory ones.
  • Repair of the cylinder head, including repair of cracks, replacement or restoration of chamfers of valve seats and guide bushings, installation of new valve stem seals, restoration or replacement of valves, camshaft and pushers.
  • Repair of the cylinder block - repairing cracks, installing new liners, treating cylinders with abrasive products, boring cylinders, repairing the crankshaft niche, leveling the mating surface.
  • Crankshaft repair.
  • Collection and installation of the engine.
  • ICE running-in, which implies a long-term operation of the engine at idle. This stage allows you to run all the components and ensure they fit for stable engine operation in the future.
  • Adjust idle speed, exhaust emissions and ignition timing.

The working life of the power unit directly depends on the life of its individual components. The resource of the engine of foreign models of cars is 250-300 thousand kilometers, domestic - about 150 thousand kilometers.

To increase the working life of the motor, it is necessary to follow the operating rules established by the car manufacturer, carry out regular maintenance and purchase only high-quality spare parts for overhaulengine.

engine gasket kit

Why is the engine overhauled?

The main goals of regular overhaul of internal combustion engines are:

  • Improve the quality of car performance.
  • Increasing the working life of the engine and reducing the risk of its failure.

It is possible to prevent malfunctions and the need for major repairs if the car owner monitors the following parameters:

  • The quality of the engine oil used.
  • Timely replacement of oil, air and fuel filters.
  • Correct adjustment of the internal combustion engine.
engine stalled and won't start

How much does an engine overhaul cost?

The minimum cost of overhaul is 40 thousand rubles. This is taking into account all spare parts, provided that the replacement of the set of gaskets for the internal combustion engine and piston rings is required. For the correct calculation of the cost, the following nuances are taken into account:

  • Quality, quantity and cost of components.
  • Cost of repairs.
  • The cost of specialized repair of the cylinder block and cylinder head.

When calculating how much an engine overhaul costs, there are several things to consider, one of which is high-quality engine oil filled during the break-in period. As a rule, a thick lubricant is used first, which after 1-3 thousand kilometers is replaced by the one recommended by the car manufacturer.

Vehicle run-in shouldcarried out correctly: revolutions should not exceed 3 thousand, speed - 100 km / h. The load on the power unit gradually increases after the first thousand kilometers. If all conditions are met, then the working life of the internal combustion engine will increase by 80% at least.

Overhaul of the power unit is an expensive and time-consuming job that requires special skills and the installation of high-quality spare parts. Timely diagnostics, maintenance and repair can extend the life of the engine.

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