An oil filter pretty much does what it says on the tin: it is the part of your car’s engine which filters the oil. It is a device which is typically about the size of a tin of baked beans which is absolutely crucial to the smooth running of your engine.
The filter’s job is to remove all impurities or contaminating bodies from your engine oil. If little specks of hard substances get into the oil stream then they can rub up and down against vital pieces of machinery and can wear them out much faster. If one of these specks of dirt or tiny chips of stone, for example, is big enough, it can get lodged in part of your engine and stop a piston from moving or a valve from closing. This could have serious consequences on the overall performance of your engine and could cause problems which cost hundreds, if not thousands, of pounds to correct.
The oil filter on your car is there so that this doesn’t happen. It helps to clean all of the engine oil to remove all of these impurities before they can go on to cause major damage to the working parts of the engine.
But over time, as the filter attracts more dust and dirt, it can start to get clogged up and begins to stop working as effectively as it did before. If the filter becomes too blocked up to do its job properly then dirty oil will continue to circulate around your car’s engine which will lead to reduced oil pressure and the risk of impurities having a drastic effect on your car’s internal workings. It is therefore extremely important that you change your oil filter on a regular basis.
Your owner’s manual should give you a guide as to how often you should change your oil filter as it will vary depending on the make and model of your vehicle. If when you drain the oil from your car to replace it, it looks very dirty then you will definitely need to consider replacing your oil filter.
If you drain the oil into a transparent container and leave it to cool down once you have let it all run out, you will be able to see if there is a lot of sediment gathering at the bottom. If there is sediment present then this is a clear indicator that you will need to replace your oil filter as soon as possible.