Engine lubrication is very important since if the lubricating film is cut there is a risk of piston seizure. However, the oil used is not completely pure and must be filtered. This is where the oil filter comes into play, retaining many dirt particles with its fine pores. If it is clogged, it should be replaced as soon as possible. In this article we will explain how to change your oil filter and what is the best filter and oil combination.
Why is change so important?
A worn or used air filter that has reached the end of its useful life is no longer able to maintain the flow and required filtering capacity due to clogged pores. In the worst case, they may even leak very little or no oil. A protection valve then opens, which guides the unfiltered oil into the engine compartment. If a vehicle with a worn oil filter is used for a long time, dirt particles can cause tiny scratches on the metal which could eventually cause engine failure. Thanks to the most advanced technologies the oil filter change interval has increased enormously. If you choose a quality product you can count on a performance of up to 60,000 kilometers.
Characteristics of oil filters
Most of the characteristics of the air filter such as the thread used and the volume cannot be determined as they are indicated by the vehicle manufacturer. However, the following features can be chosen :
- There are spin-on filters and filter cartridges. The former are the easiest to use and will fit in virtually any vehicle. For filter cartridges you must have the appropriate housing that can be prepared together with the cartridge before changing.
- A check valve prevents the oil from returning to the pump after turning off the engine. This minimizes sediment and oil flow can be restored more quickly.
- Pressure relief valves balance possible oil pump pressure changes. This can extend the service life, however, in practice these changes are not a problem if the pump is operating normally.
Filter paper and adapter take over the main function and are largely responsible for the service life. Some dealers indicate shelf life directly, some do not. Quality products are promoted as such and offer a long shelf life. If in doubt you should consult the test reports or trust the large and possibly more expensive brands.
When you change the oil filter you also have to change the oil. Although this is not officially stated, it should be respected. Finding the right oil is almost a science, and opinions vary widely. The most important are the classification and specification of the oil ( example: 15W-40 or Mercedes Benz 229.1). Some are manufacturer specific, others are generic. A distinction is made between mineral and synthetic oils. The latter are generally considered of better quality because they are heat resistant and offer better cold start characteristics. There are also high lubrication oils and “long life” type oils. The former avoid engine load thanks to their characteristics and contribute to consuming less fuel. The latter are known for their especially long service life, however, this can only develop if the filter also has the corresponding durability. For more information on oil, see the RACE website.
For replacement the following tools are needed:
- the vehicle manual
- a new, suitable oil drain plug
- a container for the oil
- a rag
- a lifting platform
- or a ramp or ditch
- or (emergency solution) a lifting jack
- a plastic bag
- a brush
- a screwdriver, if applicable,
- a spanner, if applicable,
- an oil filter wrench, if applicable
Preparation: If you use a cased filter cartridge, it should be properly prepared. Place the cartridge and the O-rings in the housing and close it with the end caps. With the help of the air filter wrench these can be fixed tightly. Start the vehicle and let it run for several minutes. Open the hood after shutting down the engine and find the old fuel filter and the oil filler neck that you now remove. Raise the vehicle and locate the oil drain plug. The position is indicated in the manual. Place a container under the bleed screw to collect the oil.
Step 1: Open the bleed screw with the corresponding tool (screwdriver or spanner) and wait until no more oil comes out of the crankcase. The bleed screw is disposed of with the old oil. Set the container aside and lower the vehicle.
oil filter change tipsStep 2: Place the plastic bag over the old filter and remove it.
- In the case of screw- on filters, remove the complete housing and wipe the threaded hole dry. Now take some fresh oil with the brush and soak it in carefully. Also add some engine oil to the new filter.
- In the case of filter cartridges with a housing, you should remove the old housing if you want to continue using it, clean it with a cloth and fit the new filter cartridge together with the ring seals. Then clean the threaded hole with a rag, brush some fresh oil on it and pour some oil on the filter.
- In the case of filter cartridges with fixed housing, open the housing with the oil filter wrench and remove the filter cartridge and the O-rings. Clean it with a cloth. Now fit the new filter cartridge together with the O-rings and add a little oil. Close the case again.
Step 3: Raise the vehicle again, clear the outlet hole with a cloth of any debris and fit the new bleed screw with the corresponding ring seal. You should first fix them manually and tighten them an additional half turn with the corresponding tool.
Step 4: Lower the vehicle and add oil to the top mark on the dipstick, but do not exceed it. Then screw the oil filler cap back on.
Step 5: Start the engine, accelerate a couple of times and let the engine run for a few minutes to start the oil circuit. Check the oil level again with the dipstick and add more if necessary. If the oil level is good, the change is done.
oil change guideNote: Residual oil is a hazardous material and therefore should not be disposed of with household waste by pouring it down the drain. All objects that have come into contact with the oil must be disposed of with the hazardous waste. Some shops accept residual oil for a fee. In addition, there are residual oil buyers who sometimes even stop for it. The first meeting point should be the local recycling center. Anyone who knows what to do with the residual oil can consult the RACE or ITV website for more information. There is also an article on the used oil regulation in Wikipedia.
Possible mistakes and risks
Changing the oil and oil filter can be a very messy job if you are not careful. However, you do not have to be a handyman to do it and you do not have to have much experience in vehicle repair. Still mistakes can happen and there are also some risks to be aware of when working with hazardous materials.
- Oil leakage – If you detect an oil leak after the change, the oil filter or crankcase oil drain screw may not have been fitted correctly. It is also possible that the oil filler cap has not been fitted correctly. Check all threaded connections.
- Oil level light: This indicator light has been on vehicles for many years. It even still exists in modern cars that have an on-board computer. What is measured varies by manufacturer and model, therefore it may indicate an error after the change. Don’t worry, it usually turns itself off again in a few minutes. However, if this is not the case, it is recommended to go to the workshop just in case.
- Large amounts of oil have hit the street – The container has not been placed correctly under the crankcase or the oil filter has been screwed in without paying attention and it is ready is a disaster that is also dangerous. If a large amount of oil has really permeated the street or, still, in the direction of the sewer, you have to call the fire brigade or the citizen protection service. They help with cleanup and damage limitation. Whoever does not do this and ignores the puddle of oil commits a punishable act and runs the risk of a prison sentence. Small amounts can be assimilated with oil binding agents and properly disposed of.
Dmitry Petrov is an engineer who specializes in materials science, and has a deep passion for all things related to automotive technology. He is a true motorhead at heart, and spends much of his free time tinkering with engines and studying vehicular dynamics.