The routine maintenance procedure for a car is not just a formality, but a vital ritual on which the life of the power plant directly depends. Many owners mistakenly believe that it is enough to simply update the lubricant, ignoring the associated elements of the cleaning system. However, the question of which filters are changed when changing the oil requires detailed consideration, since skipping one of the stages can negate the benefits of a fresh consumable.
Modern internal combustion engines operate in extreme conditions, where temperatures and pressures reach critical values. In such a hostile environment oil filter takes on the role of the first and main barrier that protects rubbing parts from abrasive wear. Ignoring its replacement or installing a low-quality analogue risks rapid contamination of the new oil with friction products and carbon deposits.
In this article we will analyze not only the main filtration element, but also the accompanying components, which are often recommended to be replaced as a whole. Understanding the relationship between fuel quality, air purity and lubricant condition will help you make an informed decision about the scope of work during your next visit to a service center or garage.
Main element: oil filter
Of course, the main answer to the question of what must be replaced along with the lubricant is oil filter. This compact unit allows the entire volume of oil circulating in the system to pass through itself, retaining mechanical impurities, metal shavings and oxidation products. Structurally, it consists of a housing with a filter element and a bypass valve.
During each regulatory procedure, this element must be replaced with a new one. The filter material (usually special paper or synthetic fiber) has limited dirt holding capacity. If you leave the old element, a flow of contaminated oil will flow through it, or it will work bypass valve, releasing unclean liquid directly into the engine channels.
⚠️ Warning: Never attempt to wash and reuse a disposable oil filter. A paper curtain degrades from temperature and time, losing its properties, and attempts to blow it with compressed air only destroy the structure of the material.
It is important to consider that there are different types of cases: all-metal (“glasses”) and cartridge (replaceable elements). In the latter, only the inner insert is changed, which is more environmentally friendly, but requires careful checking of the O-rings. The quality of the seal is no less important here than the quality of the filter paper itself.
Do I need to change the air filter?
A controversial situation often arises: is it necessary to touch air filter, if it's time for an oil change? Although these systems are technically independent, their state is closely interrelated. The air filter cleans the air entering the cylinders for mixture formation. If it is clogged with dust, the engine begins to “suffocate”.
The consequences of installing a dirty air filter can be serious. Violation of the proportions of the fuel-air mixture leads to incomplete combustion of fuel. As a result, significantly more unburned fuel and soot enter the engine crankcase through the piston rings, which instantly contaminates the fresh oil. Lubrication resource in this case it drops significantly.
Visual inspection plays a key role here. If the filter looks dark and dense in the light, its replacement is mandatory, even if the mileage is still “seemingly” too early. For diesel engines with particulate filters, the cleanliness of the incoming air is critical for proper regeneration processes.
How often should you change the air filter in the city?
In a metropolis with a high content of dust and exhaust gases, it is recommended to change the air filter every 10-15 thousand kilometers, even if the factory regulations allow 30 thousand. Saving on this element leads to excessive fuel consumption and loss of dynamics.
The effect of the fuel filter on oil cleanliness
The fuel system also deserves consideration when discussing comprehensive maintenance. Fuel filter traps rust, paraffins (in diesel) and mechanical impurities before they enter the injectors. Although it does not have a direct connection with oil, an indirect connection is obvious through the quality of combustion.
If the fine fuel filter is clogged or allows dirt to pass through, the spray pattern of the injectors is disrupted. The fuel burns inefficiently, forming carbon deposits on the valves and pistons, which are then washed off by oil. In diesel engines, poor fuel can cause diesel to enter the crankcase through the exhaust gas recirculation system, diluting the lubricant.
The fuel filter replacement schedule is usually longer than that of the oil (for example, every 60 or 120 thousand km), so it is not changed at every oil change. However, if the mileage is approaching the service interval or the quality of fuel at gas stations is in doubt, a joint replacement would be a reasonable preventative step.
- 🚗 Gasoline engines: the filter is often built into the fuel pump module or located under the bottom, and is changed less often.
- 🚛 Diesel engines: require regular replacement of the sediment filter to remove water and paraffins.
- ⛽ Fuel quality: when refueling at unverified gas stations, the fuel filter replacement interval should be reduced.
Comparison of resources of various filter elements
To better understand the timing of replacement, it is useful to have before your eyes a comparative table of resources of various elements. It is important to understand that the indicated figures are averages and depend on the operating conditions of the vehicle. Aggressive driving, traffic jams and dusty roads shorten the life of any filter.
| Filter type | Average resource (km) | Criticality of oil change | Consequences of ignoring |
|---|---|---|---|
| Oily | 10 000 – 15 000 | 100% (Required) | Oil starvation, engine wear |
| Air | 15 000 – 30 000 | High (Recommended) | Excessive fuel consumption, oil contamination |
| Fuel | 40 000 – 80 000 | Average (According to regulations) | Loss of power, fuel injection pump failure |
| Salon | 10 000 – 20 000 | Low (For comfort) | Bad smell, foggy windows |
From the table it is clear that filter resource varies greatly. The cabin filter, although it does not affect the operation of the engine, if heavily contaminated, can become a source of bacteria and an unpleasant odor in the cabin, as well as reduce the efficiency of the air conditioning system, which indirectly increases the load on the generator and engine.
Buy filters as a set (oil + air + cabin) - this is often cheaper and guarantees that all elements will be of the same year of manufacture and of high quality.
Replacement technology: important nuances
The process of replacing filters requires not only the availability of new parts, but also compliance with a certain technology. Errors at this stage can lead to leaks or malfunctioning systems. The main attention should be paid to cleanliness and correct installation.
When installing the oil filter, it is important to lubricate the sealing rubber with engine oil before tightening it. This will ensure a tight seal and will allow you to unscrew the element next time without excessive effort. The tightening torque is also important: overtightening can deform the seal, and under-tightening will lead to a loss of pressure.
☑️ Check before starting the engine
For air filters, it is important to check the integrity of the air supply pipes. Even a microcrack in the corrugation after the filter will allow unpurified air to enter the engine, negating the effect of replacing the filter element. Intake tightness - the key to the long life of the cylinder-piston group.
Original or analogue: what to choose?
The auto parts market is overflowing with offers, and every owner faces the choice between an original filter and an analogue one. Original spare parts (OEM) are guaranteed to meet the manufacturer's specifications, but are often unreasonably expensive, since the brand hides an ordinary manufacturer.
High-quality analogues from well-known brands of filter element manufacturers (such as Mann-Filter, Mahle, Bosch, Knecht) are often the same original items, but in different packaging and at a fairer price. The main thing is to avoid cheap fakes that can be dangerous to the motor.
⚠️ Attention: Avoid filters with a metal mesh instead of a paper element as the main filtration. Such “eternal” filters do not retain fine dust and abrasives, which leads to accelerated engine wear.
When choosing an analogue, pay attention to the country of production and the presence of security codes to verify authenticity. Paper quality and the adhesive used in the filter directly affects its ability to operate at high temperatures and pressures without destruction.
Choose filters from trusted specialized brands, even if they are not “original” based on the logo on the box. This is the optimal balance of price and quality.
Frequently asked questions (FAQ)
Is it possible to change only the oil and leave the old filter?
Absolutely not. An old filter contains dirt and used oil. Immediately after starting the engine, the flow of new oil will lift this dirt and spread it throughout the system. In addition, the flow of the old filter may be impaired, which will lead to a drop in pressure.
How often do you need to change the oil filter in city mode?
In city traffic jams, where the engine works a lot and the mileage stands, the oil and filter age faster in terms of engine hours. It is recommended to reduce the replacement interval to 7-8 thousand kilometers of actual mileage, changing the filter every time.
Does replacing all filters affect the vehicle warranty?
Replacing filters with high-quality analogues does not void the warranty if the service has certificates for spare parts and documents confirming their quality. However, to maintain the warranty, it is easier and safer to undergo maintenance at an authorized dealer during the warranty period.
Do I need to flush the engine when replacing the filter?
If you use high-quality oil and change it regularly, flushing is not required. Modern oils contain detergent additives. Flushing is only necessary when switching from mineral oil to synthetic oil or if carbon deposits and deposits are found in the engine.