What are the general parts of an automobile engine overhaul?

Although engine overhaul is a general concept, there is also the so-called "engine overhaul package", but the overhaul engine we usually talk about is mostly for the core components of the engine such as cylinder liners, pistons and valves, including boring cylinders, grinding valves, grinding shafts, cold-pressed ducts and other processes and valve oil seals, front and rear crankshaft oil seals, camshaft oil seals, piston rings, timing chains, tensioners, crankshaft bearings, connecting rod bearings and other extended operations.

The general car needs to overhaul the engine is mostly some old cars that burn oil, stubborn oil leakage, and low cylinder pressure to reduce the power, which is mostly caused by long-term wear or aging of the engine, and there is no other way to disassemble the engine to solve the problem.

One of the regular maintenance: the three filters and the oil need to be replaced.

In the routine maintenance of vehicles equipped with gasoline engines, the most frequent replacement is the three filters and oil, which refer to the gasoline filter, air filter and oil filter, their role is to filter the impurities in the gasoline, air and oil, to prevent impurities from entering the engine, causing abnormal wear and tear of the engine or abnormal work. The ultimate purpose of replacing the three filters is to better protect the engine and extend the service life of the engine as much as possible, which is also the most routine maintenance item.

Routine maintenance two: to regularly replace the timing belt The main function of the timing belt is to drive the valve mechanism of the engine, so that the intake and exhaust valves of the engine are opened or closed at the appropriate time to ensure that the cylinder of the engine can be inhaled and exhausted normally. In some models, the timing belt is also responsible for driving the water pump, such as the Jetta EFI, Santana 2000, Bora, Audi and other models in the Volkswagen models.

Belts belong to rubber parts, and with the increase of engine working time, timing belts and timing belt accessories, such as timing belt tensioners, timing belt tensioners and water pumps, etc., will wear or age. Therefore, where the engine is equipped with a timing belt, the manufacturer will have strict requirements, in the specified cycle to replace the timing belt and accessories regularly, the replacement cycle is different with the structure of the engine, generally in the vehicle to 60,000-100,000 kilometers should be replaced, specific replacement.

Automobile maintenance enterprises are defined as: automobile maintenance enterprises that have the ability to maintain, repair and replace the whole vehicle, each assembly and main parts of the repaired model at all levels, so that the technical condition and operation performance of the vehicle can be completely (or nearly completely) restored to the technical requirements of the original vehicle, and meet the provisions of the corresponding national standards and industry standards. Its business scope is wide, and it can maintain, repair and replace the whole vehicle, each assembly and main parts of the repaired model, and is divided into a class of automobile maintenance enterprises and a class of automobile maintenance enterprises according to the size and conditions of completion testing equipment.

The definition of special automobile maintenance business is: engaged in automobile engine, body, electrical system, automatic transmission, body cleaning and maintenance, painting, tire dynamic balance and repair, four-wheel alignment inspection and adjustment, oil supply system maintenance and oil replacement, fuel injection pump and fuel injector maintenance, crankshaft grinding, cylinder boring, radiator (water tank), air conditioning maintenance, automobile decoration (tarpaulin, seat cushion and interior decoration), door and window glass installation and other special maintenance operations (three categories).

The conditions for the opening of the automobile repair industry (1997 edition) divide automobile maintenance enterprises into three categories---

A class of automobile maintenance enterprises: engaged in automobile overhaul and assembly repair, can also be engaged in automobile maintenance, automobile minor repair and automobile special repair; Class II Automobile Maintenance Enterprises: Engaged in Primary and Secondary Maintenance of Automobiles and Minor Repairs of Automobiles; Three types of special maintenance households:

Specializing in the project for body repair, painting, tarpaulin, seat cushion and interior decoration repair, electrical appliances, instrument repair, battery repair, radiator, fuel tank repair, tire repair, installation of car door and window glass, air conditioner, heater repair, fuel injection pump, injector, carburetor repair, crankshaft grinding, cylinder boring, body cleaning and maintenance and other special repair or maintenance.

The revised Conditions for the Opening of the Automobile Maintenance Industry (2004 Edition) retains the three classification modes of the original standard, but the connotations of the three types of enterprises have changed compared with the original definition.

1) Canceled to engage in cars.

The first and second class maintenance and minor repair are the definition of the original two types of enterprises operating the business, and the first and second types of enterprises are defined as vehicle maintenance enterprises, and they are divided into the first and second types of vehicle maintenance enterprises according to the scale and completion inspection equipment conditions;

2) Establish the definition of "vehicle type (small car, large and medium-sized bus, large truck)", and link it with the repair model within the business scope of the vehicle maintenance enterprise;

3) Increase the engine, automatic transmission and other large automobile assembly into special maintenance items, adjust the original special maintenance project electrical and instrument repair to electrical system maintenance, so that the three types of special maintenance households with the specified conditions can be engaged in the maintenance and repair of a certain assembly and a certain system of the car.

The new classification is not only in line with the current situation of the automobile maintenance industry, but also has a good connection with the technical content of the original standard, which is conducive to the smooth implementation of the new standard after the introduction of the new standard; It also adapts to the development requirements of the industry management department for the adjustment and reform of the automobile maintenance industry. In the current standard, the business scope of the first and second class enterprises is the same, and the operation of the third type of business has a certain depth, which solves the problem of over-scope operation in the current automobile maintenance market.

1.Mechanical part: overhaul kit, one set of valve intake and exhaust, one set of piston rings, one set of cylinder liners, two thrust plates, and 4 pistons.

2.Cooling system part: water pump, engine upper and lower water pipes, large circulation iron water pipes, small circulation hoses, throttle water pipes.

3.Fuel part: upper and lower oil rings of fuel injectors, gasoline filter.

4.Ignition part: whether the high-voltage line is swollen or leakage, it will be replaced, fire piston, air filter.

1. Regularly change the engine oil: the engine oil is the lubricant of the engine, which can lubricate, clean, cool, seal, reduce wear and other functions of the engine, and is also the "blood" of the engine. Failure to change the oil for a long time can lead to severe wear and tear on engine parts, reducing the life of the engine.

The manufacturer recommends replacing it every 5,000 or 10,000 kilometers. Therefore, when it comes to choosing a motor oil, it is necessary to choose a good quality.

2. Regularly change the three filters: the three filters refer to the air filter, oil filter and gasoline filter. The three filters can provide the engine with the effect of filtering impurities, protect the engine, and also improve the working efficiency of the engine.

The regular maintenance interval of the three filters is the same as that of the engine oil.

3. Battery: The battery is used to ensure that the engine can start normally, and the color of the "electric eye" should be checked in the observation window at the upper part of the battery to see whether it is green. The battery life is generally about two years, and the life may be shorter in cold weather.

4. Brake fluid: Brake is very important for driving safety, brake fluid has strong water absorption, can automatically absorb moisture in the air. Therefore, it is necessary to check the level of brake fluid regularly, and add or replace it in time if it is lower than the standard value.

5. Coolant: The coolant is to ensure the normal operation of the engine, and it is necessary to regularly check whether the coolant level is at the standard value, and regularly check whether the coolant pot is leaking, and the coolant needs to be replaced once a year on average. How do you add coolant?

6. Power steering fluid: Power steering fluid is commonly known as direction oil, and it is necessary to regularly check whether there is any leakage or obvious abnormal noise. Electronically assisted models are maintenance-free, so there is no need to change the steering oil. The maintenance interval of directional oil is about 60,000 kilometers.

Thank you.

1. Bake the oil bottom with a blowtorch.

Baking the oil bottom with a blowtorch in winter will not only cause chemical changes in the additives in the oil, but also lose the original ones'performance, but also will make the oil cementation, oil bottom deformation, easy to cause disasters. The best practice is to use the appropriate oil for the local minimum winter temperatures. Where possible, it is best to park the vehicle in a garage with thermal insulation facilities.

The more advanced removal methods are ultrasonic removal and nuclear spray removal, but the most commonly used and simplest methods are physical removal and chemical removal. Both methods can also be used together.

2. The engine temperature is not afraid of high or low.

Some people think that the engine temperature is not afraid of high or low when driving. In fact, when the engine temperature is low, it is also very harmful. The service life of the engine should be ensured by driving at the normal temperature specified in the car's instruction manual.

3. The tighter the belt of the water pump fan, the better.

The tighter the belt, the better. If the belt is too tight, it will not only elongate or break, shortening the service life of the belt, but also lead to deformation and bending of the generator shaft and water pump shaft and early damage to the bearing due to excessive tension. The tightness of the automobile engine Nianwei fan belt should meet the technical requirements, and the deflection of the normal belt assembly is generally 10-15mm.

4. The engine is heated up at idle speed with buried.

When heating up at idle speed, due to the low speed, the oil pump can not press the lubricating oil into the lubricating surfaces quickly, and the oil pressure is also low, so that the moving parts of the engine work in the state of dry friction or semi-dry friction; Due to the poor atomization of the fuel at low temperature, the unburned fuel will flow into the crankcase, wash away the oil film on the cylinder wall, and also accelerate the wear of the parts. Therefore, a few seconds after the engine starts, a fast idle speed should be used to heat up and improve the lubrication conditions of the engine.

5. Blindly remove the engine thermostat.

If the thermostat is blindly removed due to the high temperature of the engine, the coolant can only be circulated for a large period of time, and the cooling intensity cannot be adjusted, which is difficult to ensure that the engine works at a more suitable temperature, but makes the engine often work at a low temperature, resulting in a decrease in engine power, wear and tear, and an increase in fuel consumption.

If the engine temperature is still high after the engine thermostat has been faulted or replaced, the other parts of the cooling system should be overhauled and the thermostat should not be removed.

Usually mechanics say engine overhaul, but many novices actually don't they don't understand what an engine overhaul is and don't know why it needs to be overhauled. So what are the projects for engine overhaul?

If the engine chain is timed, it is necessary to replace the timing chain and tensioner, in addition to machining, boring cylinder lining, grinding shaft, cold pressed conduit, overhaul kit, arc front oil seal, arc rear oil seal, camshaft oil seal, oil pump, comparison valve and so on.

Ignition section: If the high-voltage circuit swells or leaks, replace the high-voltage circuit and ignite the piston.

Air intake: Generally mainly includes air filter.

Mechanical part: generally mainly includes a set of valves, a set of piston rings, a set of cylinder liners (if it is a 4-cylinder engine), two thrust plates, and four pistons.

Cooling system: water pump (water pump blade corrosion or water seal leakage), engine slag transport upper and lower water pipes, large circulation iron pipes, small circulation hoses, throttle pipes (aging and expansion must be replaced).

Cooling system such as Tongliang: generally mainly includes water pump (pump blade corrosion or wheel banquet water seal seepage), engine water supply and drainage pipe, large circulation iron pipe, small circulation hose, throttle pipe (aging expansion must be replaced), thermostat, etc. The general fuel part mainly includes the upper and lower oil rings of the injector and the gasoline filter; Ignition section:

If the high-voltage line is swollen or leaking, it will be replaced, and the piston will be ignited; The upper and lower oil rings of fuel injectors and gasoline filters.

Other accessories: generally mainly including antifreeze, engine oil, oil tank, detergent, engine metal cleaner or all-purpose water.

Parts to be inspected: generally mainly including whether the cylinder head is corroded or uneven, crankshaft, camshaft, timing belt tensioner, timing belt adjustment wheel, timing belt, engine belt and adjustment wheel, rocker arm or rocker arm shaft. If it is a hydraulic tappet, check the hydraulic tappet.

Fuel: The overhaul kit includes cylinder head gaskets, various oil seals, valve cap gaskets, valve oil seals, gaskets, etc. Engine overhaul projects generally include overhauling the engine, processing the cylinder head plane, boring the cylinder, cleaning the water tank, grinding the valve, inserting the cylinder liner, pressing the piston, cleaning the oil circuit, repairing the motor, repairing the generator and so on.

That's all about engine overhaul projects.

There are three main types. Overhaul engine, overhaul transmission, overhaul girder (suspension) shouting.

1. Engine:

Replace the main internal parts of the engine. It mainly includes crankshafts, pistons, connecting rods, cylinder liners, valve assemblies, piston rings, piston connecting rods, valve seat inserts, crankshaft connecting rods, piston rings, timing belts (some cars do not need to be replaced by a hail if they are timing chains), engine overhaul kits (including all gaskets, oil seals, valve oil seals, cylinder gaskets, oil pan gaskets, crankshaft head oil seals, but excluding crankshaft rear oil seals), crankshaft rear oil seals, transmission front oil seals, cleaning engine waterways, cleaning water tanks, changing oil and filters.

2. Transmission:

Replace the main internal parts of the transmission. Gears, gear oil pumps, bearings, seals, locking pins, etc.

3. Girder: Girder overhaul is required only when there is a collision or fracture over time, and it is generally necessary to go on the girder correction platform to correct the girder.

Automobile overhaul has strict quality requirements. After repair, the assembly and some accessories must be tested for performance and can only be loaded after passing the test. After the overhaul, the car should be adjusted and tested in accordance with the repair technical standards, and it will be shipped out of the factory only if it meets the standards.

To this end, the automobile repair factory should have a strict production management and quality management system, perfect process equipment and a relatively high technical level. In areas with a large number of cars, it is advisable to set up factories according to different car types or different models to ensure the quality of repair and reduce repair costs.