Car Engine Maintenance: When and What To Do

by | Aug 20, 2022 | Articles

Issues addressed in the material:

  • What types of vehicle engine maintenance can be distinguished
  • When do you need to carry out the first car engine maintenance
  • When and how to clean the car engine
  • What malfunctions can be detected during maintenance without removing the car engine

The engine is rightly called the heart of the machine, which requires no less thorough care and maintenance than your body. In order for it to work uninterrupted and be reliable, in addition to a daily inspection before a trip, regular maintenance of the car engine is necessary. This article is dedicated to this process.

Car engine maintenance right after purchase


The first 3-5 thousand kilometers of a new car are the most important period during which the owner must act wisely to ensure a long period of trouble-free service. The details of all components and assemblies are still rubbed against each other, so you should not fully load the vehicle and give maximum speed to the engine. Full warming up of the engine before starting to move allows you to ensure stable operation of the engine.

The first maintenance trip requires a number of mandatory manipulations. Among them: broaching threaded connections, measuring the air pressure in the tires with a manometer, checking the presence and level of technical fluids and oils in the internal combustion engine, gearbox, axles and power steering tank (if any) or in the steering column, antifreeze in the radiator tank, brake fluid in the reservoir of the brake master cylinder and clutch hydraulics (if any), fuel in the reservoir. Using a load plug, you need to check the battery charge, the level and density of the electrolyte and be sure to fix the battery with a special holding device in place, tighten the terminals according to their polarity. It is necessary to test the operation of windshield systems and washers (is there fluid in the tanks, do the sprayers work).

Before starting the engine for the first time, fuel must be pumped into the carburetor with a gasoline pump. After starting the engine, the driver should carefully check for leaks of oil, fuel, antifreeze or antifreeze. Let the engine idle, then press the accelerator, gradually adding revolutions, and listen. If there are no extraneous suspicious noises, you can start moving.

Maintenance of the car engine in the main period of operation

In general, the maintenance of a car engine includes:

  • cleaning mounted units from pollution, removing tarry deposits of oils, soot;
  • checking and tightening threaded connections;
  • replacement of oil and antifreeze / antifreeze, filters in the fuel, oil and air systems;
  • adjustment if necessary.

Particular attention during the first maintenance of a car is given to broaching bolts and nuts in the mounting systems of the exhaust manifold, muffler and engine mounts. During the second maintenance, check and broach (if necessary) fasten the cylinder heads, adjust the valve clearance in the gas distribution system, check and adjust the tension of the alternator belt, timing, etc.

engine maintenance

During the main period of operation of the car, various types of maintenance are carried out:

1. Daily engine maintenance.

This type of maintenance includes the following:

  • Visual inspection of the engine.
  • Checking the oil and coolant levels, and topping up if necessary.
  • Evaluation of the motor (by instruments on the panel and by ear).

2. First maintenance.

This type of maintenance includes the following:

  • Checking the reliability of fixing the engine units on the frame and body.
  • Checking the reliability of fixing the equipment directly to the engine (generator, gasoline pump, muffler).
  • Checking the reliability of fastening the front supports.
  • Checking the oil pan for leaks, if necessary – tightening the bolts.
  • Adjustment.
  • Carrying out operations according to the lubrication chart.

3. Second maintenance.

Second maintenance includes the following:

  • Complete all first maintenance items.
  • Check and tighten (if necessary) the cylinder head nuts.
  • Adjustment of thermal clearances of valves and, if available, pushers and rockers.
  • Compression check in cylinders.
  • If necessary, remove carbon deposits.

The first maintenance operations do not require disassembling the engine, while during the second MOT it is necessary to remove the valve covers from the cylinder heads for diagnostics and adjustment of the clearance in the timing.

Each automaker develops guidelines for the prevention of malfunctions and engine repairs. So, the tightening torque of the head of gasoline engines is lower than that of diesel engines. At the same time, it is necessary to evaluate the fastening of the aluminum cylinder head on a cold engine, and cast iron on a heated one.

At negative temperatures, tightening of the cylinder heads is prohibited. The motor must be warmed up and only then proceed to tighten the fasteners. Tighten the bolts evenly, in two steps, according to the recommended by the manufacturer scheme, which takes into account the design features of the engine. For broaching use a special torque wrench. This type of work is carried out simultaneously with tightening the exhaust system mounting bolts. The procedure should be completed by checking the clearances in the valves and, if necessary, adjusting them, the specificity of which is determined by the design of the engine.

During the period of operation of the car, the permissible clearance between the valves and pushers often changes, as a result, the filling of the combustion chamber of the cylinders with the fuel mixture deteriorates and the removal of exhaust gases is difficult. All this leads to increased fuel consumption and lower engine power.

Engine malfunctions that can be detected and repaired during maintenance

The operation of the car engine must be characterized by reliability and continuity, the ability to develop power sufficient to ensure normal traction of the car and at the same time not exceed the established norms of fuel and oil consumption.

  1. The reasons for the loss of engine power and a concomitant increase in fuel consumption of a car can be: various malfunctions of the power supply system, accumulation of soot in the connecting rod and piston group, deposits in the intake system and its insufficient sealing, rust, scale and decomposition products of the coolant in the radiator, misregistration of the gas distribution mechanism, low compression in engine cylinders. When carrying out maintenance, it is worth paying attention to these points in the first place.
  2. Excessive oil consumption and the appearance of soot in the exhaust of a car are caused by: deterioration of the central piston group, sticking of piston and oil scraper rings, deformation of piston grooves, scratches and cracks in cylinder liners, leaking valve seats and crankshaft liners, excessive contamination of the crankcase ventilation system. Also, a change in the color of the exhaust can also be a signal of incorrect operation of the carburetor or high-pressure fuel pump in diesel cars.

car exhaust fumes

  1. A decrease in compression can be caused by: malfunctions of the valve system (wear of seats, guide bushings, rocker arms, oil seals), worn piston group and cylinder liner mirrors, notched cylinder head gaskets due to insufficiently tightened bolts, unregulated timing gaps.
  2. Extraneous noise and tapping in the motor result from: malfunctioning valve springs and jamming of valves; deformation of the working surfaces of the pistons and sleeves; increased gaps in the gas distribution mechanism; the appearance of production on the piston fingers in the piston bosses and in the bushings of the upper connecting rod heads; the diametrical wear of the crankshaft liners surrounding the main and connecting rod necks.

The crank mechanism consists of a piston and crank groups: cylinders, pistons, piston pins and rings, connecting rods, crankshaft, connecting rod and main bearings, flywheel. Maintenance is designed to eliminate the malfunctions of parts of this group, which are manifested in smoke exhaust, increased oil consumption, pressure drop in the lubrication system, knocks, noise and vibration.

The increase in gaps becomes a common cause of “disease” for all groups of parts. So, in the crank mechanism, this leads to the appearance of vibrational manifestations, the cylinder-piston group threatens with a decrease in pressure in the cylinders and, as a result, an increase in oil consumption in the crankshaft bearings leads to a decrease in the oil pressure in the engine.

The “mirrors” of the cylinders wear out both along the axis (in the area of ​​the compression rings) and (much stronger) around the circumference (in the plane of the connecting rod). Depending on the degree of deformation, the cylinder is or is not subject to turning. During maintenance, pistons with rings are most often replaced with new ones in accordance with the internal diameter of the cylinder. Cranks, if they are deformed (cracks, bends, twists, large wear under the sleeve of the finger and liners), also cannot be repaired. Their permissible bending is 0.08 mm with a maximum twisting of 0.12 mm per 100 mm of length.

Engine repair is mandatory upon detection of: misalignment of valves, leaking valve cover gaskets and block head, any defects in the block head, knocking of main and connecting rod bearings, gas leakage, increased oil consumption, reduced power, insufficient oil pressure in the lubrication system.

Moreover, in the first three cases, the power unit can not be removed from the car. For repair / replacement of pistons with rings, cylinders, connecting rods, liners, oil pump, etc., the engine will need to be removed from the vehicle.

If several malfunctions are detected at once (valves knock, bearings “rustle”, power drops, etc.) and the vehicle’s mileage is close to the resource values ​​set by the plant, overhaul becomes inevitable. Before this, the engine needs to be washed (outside) and handed over to the hands of professionals: in a trusted and trustworthy repair shop, where disassembly, repair, assembly and post-repair testing (high-quality running of the power unit in hot or cold condition) are carried out on stands, which guarantees durability ICE work.

Cleaning and washing the car engine

The first stage of maintenance of the motor is its external cleaning, which is carried out before a checkup, diagnostics and regulation or repair work.

The surface of the engine is blown with air under pressure and wiped with a rag.

cleaning car engine

A thorough washing is carried out to determine the places of leakage of oils or technical fluids, as well as in order to remove dense deposits from dried mud and accumulated thickened oil, which interferes with normal engine cooling.

It is dangerous to use gasoline or kerosene for these purposes; it is best to use a cleaner for cold cleaning, which can be aerosol or liquid. In the latter case, a brush and water are used to apply it: the cleaner is rubbed on the surface of the engine, periodically wetting in water. After the expiration of the exposure time indicated on the packaging of the selected product, it is necessary to rinse the purifier with water, having previously closed the generator and the distributor with polyethylene.

You can use synthetic detergents (washing powder, shampoo, dishwashing detergent, etc.) by applying them with a brush as well.

After such a “bath” the engine should dry properly.

External engine cleaning is necessary as needed. As for the internal “cleaning”, for the prevention of soot, tarry and ointment deposits, special additives are used that are added to fuel, oil and antifreeze about once every three to five thousand kilometers.

Inspection of the engine during maintenance

The main purpose of the inspection of the internal combustion engine of a car during maintenance is to identify obvious malfunctions, and you need to: assess the completeness, identify leaks of fuel, oils and antifreeze, check the attachment points of the engine and its systems, make a control start. The key characteristics of the latter are lightness and time, the maximum value of which should not exceed 20 seconds. After 1-2 minutes, the start must be repeated.

Such an inspection makes it possible, on the basis of exclusively external (qualitative and quantitative) indicators, to identify the internal problems of the “heart” of the car. And if you add instrumental research to them, you can get a more detailed “picture of the disease.”

More often than others, in diagnostics during maintenance, color analysis of car exhaust gases, sound analysis of engine operation, chemical analysis of crankcase oil (products of wear of engine parts, insoluble pollution products, etc.) are used.

1. Color analysis of exhaust gases. 

By the color of the smoke from the exhaust pipe of the car, various problems in the engine can be diagnosed:

1. White exhaust – a consequence:

white exhuast smoke

  • insufficient pressure in the cylinders (due to wear of the cylinders of the piston group and incorrect operation of the valves);
  • liquids entering the cylinders (due to defects in the head or gasket burnout);
  • defective combustion of fuel (due to inefficient spraying and missing the compression stroke) – in diesel cars;
  • starting the engine at low air temperatures, delayed flashes (abnormal atomization by nozzles, waxing of fine fuel filters, fuel pump wear) – in diesel cars.

2. Light or dark blue exhaust – a consequence:

  • sticking of piston rings, general strong wear of the piston group;
  • wear of valves, guide bushings and valve stem seals;
  • untimely injection of the fuel mixture, improper operation of glow plugs, strong oil combustion – in diesel cars.

3. Brown or black exhaust – a consequence of incomplete combustion of fuel due to poor-quality atomization by nozzles (the needle is worn out or the angle of advance of the injection is reduced); incorrect setup of the injection pump; insufficient air supply (indicates that it is time to change the air filter).

4. Gray or light gray exhaust – a consequence:

  • poor running-in of piston group parts (the engine is not run-in sufficiently);
  • loss of mobility by piston rings due to high coking;
  • lack of compression in the cylinders.

Maintenance and repair of the power supply system of a diesel engine of a car must also be carried out in the case when there is no exhaust smoke at all when starting the exhaust (or it comes out in rare clubs). This means that the fuel supply is insufficient, or the valves and pistons of the high-pressure fuel pump seize, or its spring breaks, or plungers seize (perhaps their springs do not finish). The problem may lie in the nozzle needle or in the failure of the check valve.

Car exhaust prints on paper can also be used to analyze and diagnose problems.

2. Analysis of noise during engine operation.

service inspection

The seeming simplicity of the method (noise is easy to hear) makes it very common, but it is important to remember that only a highly qualified specialist (and even his assessment will be subjective) can qualitatively assess the technical condition of a vehicle’s power unit.

To obtain more accurate data, special stethoscopes are used – both the simplest ones (for example, KI-1154 is a probe with a pen and headphones), as well as more complex, resonant ones equipped with a frequency perception regulator and an acoustic camera that resonates with the vibration frequency of the unit, which allows tune the device to different frequency ranges. Electronic devices from Ekranas factory are able to pick up faint sounds.

And ultrasonic stethoscopes can detect even a slight leak of compressed gases that the human ear does not perceive. Instruments transform ultrasound into audible frequencies or into a pulse recognized by an oscilloscope.

Maintenance of diesel and carburetor engine engines varies significantly, although there are many common points.

So, the fuel system is diagnosed by analyzing the fuel mixture (its composition and consumption in accordance with the standard). Make a measurement of the carbon dioxide content in the exhaust of the car.

Cooling system . It is visually examined for leaks, overpressure (approximately 0.06 MPa) is injected to detect leaks at the junctions of nodes and assemblies. The following indicators are controlled: coolant level (if necessary, top-up), the degree of tension of the radiator fan belt. Eliminate scale and leakage.

Lubrication system . The level and quality of the oil, its pressure – these are the main indicators that are checked during maintenance. Since the state of the system immediately affects the functioning of the engine, there are no secondary elements. The master will pay attention to every detail, replace filters, flush the system, lubricate the elements (according to the regulations recommended by the manufacturer).

Diesel engine cars need specific fuel system adjustments: if early fuel injection into the cylinders is detected, it is necessary to carefully set the lead angle. They carefully monitor the tightness of the fuel supply system, regulate the operation of pumps (booster and high-pressure fuel pump), change filters, and check nozzles.

During the maintenance of gasoline engines, the carburetor is adjusted, the crankshaft speed is set to the minimum idle speed. The fuel level and tightness of the float chamber, gasoline pump, cleanliness of the air and fuel filters, the throttle closure density, and the idle valve operation are subject to assessment. Checking the tightness of the fuel tank and gas lines is an essential part of maintenance.

Maintenance of individual vehicle engine systems

  1. Crank mechanism. Drain coolant and oil from engine block. Check the degree of tightening of the bolts securing the cylinder heads to the block (if necessary, tighten them), clean the piston bottoms and the inner surface of the combustion chambers. In V-engines, the inlet pipe must be loosened to prevent interference of the cylinder heads tightening against each other. Now the nuts for fastening the head to the block can be tightened with a torque wrench.If only those types of oils and fuels that are recommended by the manufacturer are used, and the temperature regime of heating the coolant is observed (80–90 ° C), the deposit is insignificant, it does not have a serious negative effect on the operation of the motor.If the recommendations are violated, this inevitably threatens to form a detonating deposit causing a decrease in engine power and an increase in fuel consumption. In the process of maintenance remove carbon deposits, for which the intake pipe of the cylinder head is removed. Then carry out the cleaning of the piston bottom and the inner surface of the combustion chambers. The operation of the engine on leaded gasoline significantly complicates the maintenance process: in this case, the carbon must be moistened (for example, with kerosene) in order to prevent inhalation of the strong poison contained in it. If deposits on the pistons soon reappeared, this suggests that the car engine needs urgent repairs.
  2. Gas distribution mechanism.It is necessary to check and adjust valve clearances with a certain frequency – on a cold engine (in carburetor cars) when the pusher is completely lowered. Reducing the gaps relative to the values ​​recommended by the manufacturer leads to earlier opening and closing, hence the overheating and burnout of the valves, which, in turn, significantly affects the quality of the engine starting and its operation as a whole. It is necessary to clean the valves of carbon deposits and rub them to the seats.
  3. Adjustment of starting clearances.As an example, consider the adjustment of the starting clearance of the throttle valve of the first chamber on the VAZ-21083. The first condition is a cold engine. The second is the removed carburetor.It is necessary to remove the air filter to provide access to the damper, the starting clearance of which is 2.5 ± 0.2 mm. Deviation from the permissible values ​​leads to the need for adjustment by the adjusting screw. Procedure: turn the cam to the left (the expanding groove will release the pin of the shutter lever, the shutter itself will be held in the closed position due to the return spring), adjust the gap size with the screw in parameters 1.1 ± 0.05 mm (the lever opens the throttle by an adjustable amount ), return to place the nodes and parts.Next is the engine start. After about 15–20 seconds, you need to check the number of revolutions of the crankshaft of the still cold engine, the normal parameters are 2200–2600 rpm. The warmed-up engine idling holds 750–800 rpm.
  4. Lubrication system.Every day it is necessary to control with a dipstick the oil level, which should be between the min and max marks.
  5. Supply system.The cleanliness of devices and components is the most important condition for the smooth functioning of the fuel system. Maintenance includes replacing fuel filters, checking for leaks in the fuel line connections. Careful attention must be paid to hose connections: they must not be twisted or kinked.
  6. Engine idle adjustment.Conditions for adjustment work: the engine is warm, the air damper is fully open, the timing gaps are adjusted, the ignition timing is correct. The two main participants in the process: the first is the screw of the quantity of the fuel mixture and the second is the screw of the quality (composition) of the mixture, which is closed. The plug must be removed with a corkscrew to gain access.The first screw must be set on a tachometer engine speed in the range of 750-800 per minute. The second is to bring the value of the carbon dioxide (CO) content in the exhaust to 1 ± 0.3% (the carbon monoxide content is reduced to 20 ° C and 101.3 kPa (760 mm Hg)). Values ​​can be confused, so adjustment to achieve these indicators should be carried out as many times as necessary.After completing the adjustment work, sharply press the gas pedal and release it. If the motor suddenly increased speed, and then just as quickly slowed down and did not stall, it means that it is operating normally. If it stalls, the speed must be brought to the indicated values ​​and the plug of the quality screw must be changed.


Drawing from extensive expertise in the used car parts industry, Craig Sandeman has established himself as a trusted authority in automotive repair. He possesses a deep knowledge of the challenges encountered by individuals seeking reliable car parts, making him a highly sought-after expert in this field.


Potential issues, causes, and solutions have been identified in the above article based on the experiences of car owners and repairers, as well as web materials such as forum blogs and technical support bulletins. This data is supplied exclusively for the purpose of reference. Only appropriately qualified persons should perform repairs and/or changes on your vehicles.

While it’s important to keep in mind, it’s also important to note that the amount of times anything is mentioned here should not be seen as a sign of its reliability or frequency. Various owners, driving in different ways, and caring for their vehicles in distinct ways will cause two identical vehicles to perform differently.

As previously said, this material is supplied primarily for reference reasons; nonetheless, we hope that by doing so, we will be able to supply you with essential knowledge that will allow you to make informed decisions whenever you encounter any of the aforementioned setbacks.


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