How the different types of filters work

Thursday September 10 2015

A key component is the air filter, an

A key component is the air filter, an inexpensive part that can increase fuel consumption if clogged. File photo 

By Rachel Kanyoro

Imagine how your body works, the organs run the body, the heart and lungs play an important role in keeping the body function. The heart pumps blood in the body and for that to be efficiently done, impurities have to be removed.
Likewise, the heart of your car is its engine, and this is the reason it has filters that help clean out the dirty particles.
Different people have different perceptions of what the filters do in the car but Paul Goosen, Africa sales manager for G.U.D Holdings, which manufactures filters, says the use of the filter is to remove impurities such as dirt from pollution, dust, water, rust.
However, James Mubiru, a mechanic, says while filters serve the same purpose, different car manufacturers make their own filters that fit the engine of their cars. Toyota cars will have theirs, so will Mitsubishi, among other car manufacturers.
Filtration can be defined as the process where impurities such as dirt are removed from a substance, liquid or air by trapping those impurities and not allowing them to contaminate the substance in which they are apart. In case of a car, it involves taking the impurities from the air that comes into the vehicle, in the oil and the fuel used in the vehicle so that these impurities do not contaminate any part of the car. Filters in other words remove all the impurities in the air, oil and fuel system of a car.

Effects of poor filtration

Paul Goosen, Africa sales manager for G.U.D Holdings, says the dangers of having a dirty air or oil filter is that, “your engine is forced to work harder, resulting in poor fuel economy, higher emissions and possibly a loss of engine power.”
He adds, “We are not talking about rocks but small grains of dirt. Small things like these are the ones that will cause damage to your car engine.”
He adds that, when the fuel filter is dirty, it will cause a weakened fuel supply to the car’s fuel injectors, a reduction in engine power, poor acceleration and poor fuel economy, not to mention a potential breakdown.
He advises that a filter should be changed when it has reached it’s mileage and contrary to the common practice, a car owner or a mechanic should not use air pressure to blow the dust out of the engine but rather replace it.
He explains; “When you blow it, you have not cleaned it out and continued use of the filter will cause the car to use more fuel and eventually will cause damage to your engine.”

Types of filters

Air filter
Your air filter plays a key role in preventing contaminants such as dust and dirt from entering your engine. James Mubiru, a mechanic, explains that the air filter draws air through the filter and into the cylinders where air and fuel combine to power the vehicle. He adds that a dirty air filter can lead to fuel wastage.

Fuel filter
Mubiru further explains that when you press down on your gas pedal, your fuel system controls the amount of power you get from your engine by moderating the flow of fuel and air. However, fuel isn’t perfectly clean. This is why it passes through a fuel filter that picks up any dirt that might interfere with the engine’s performance.
He adds that over time, dirt and particles build up in the filter. The fuel filter needs to be replaced or it will reduce the flow of fuel to your engine, affecting your vehicle’s performance and the fuel consumption.
Goosen says the characteristics of a good filter are; the car will get efficient filtration, high dust holding, will meet the correct space requirement, have an optimised air flow rate, and have stability under wet conditions where the dust will not create a paste when it mixes with water.
He points out that one cannot tell that this filter is better than the other from just looking at it. The only way you can differentiate the filters is by knowing the parts the filters are made of and this also determines the quality.
Oil Filter
An oil filter is a filter designed to remove contaminants from engine oil, transmission oil, lubricating oil, or hydraulic oil.


Signs of a faulty filter

David Kaleebu, a mechanic at Southern Oils and Logistics, says every car owner has to do basic car maintenance and regular checks. He adds that the warning signs, will be when your car gives a humming and hawing sound, when the engine hesitates, stalls or lags when you step on the pedal, then a clogged filter might be the culprit.
He adds that when the recommended mileage expires, then it will be time to change the filters.
Kaleebu further advises that motorists should be very careful while purchasing filters because there are a lot of fake ones floating on the local market.
“These fake partss do not perform as per the recommendations of the car manufacturers; some filters have a few metres of the filtration paper,” he explains.
Kaleebu adds that some of these have no functioning valves as these valves have to open when the engine is on and close when the engine is off. The fakes lack valves so engine knocks out with time,” he adds.


Air filter
David Kaleebu, a mechanic at Southern Oils and Logistics Limited says, changing the air filter on your car will take about 10 minutes and will only cost you the price of a new filter, which will cost you between Shs10,000 and Shs25,000. Here’s how to do it:
• Pop open your hood and locate the air filter in your car, which is housed within a black case with metal clips on either side.
• Open the case and look at how the old filter sits inside of it. By making note of this, you will have an easier time putting the new filter in.
• Remove the old filter while making sure nothing falls into the bottom of the filter box.
• Put the new filter in, close the case, and secure it with the nuts.

Oil filter
Kaleebu says while changing the oil filter, one should not change the oil when it is hot. He explains, “If you change it while it is hot, you may get burned.”
He adds that it also takes about 10 minutes to change your oil filter and will cost around Shs10,000 to Shs25, 000. Here’s how to change your oil filter:
• Make sure your car is on level ground so you can safely jack up your car.
• Locate the oil pan under your car and unscrew the drain plug to drain the old oil. Be sure you drain the oil into a recycling container so you can recycle the old oil at your nearest full service gas station or garage, and then replace the drain plug.
• Locate your oil filter and use an oil filter wrench to remove the filter.
Be careful as old oil will still be on the filter. Make sure the rubber gasket on the old filter comes off with the filter.
• Lubricate the rubber gasket on the new filter, then fill the new oil filter about 2/3 with new oil.
• Screw the new filter into place as tightly as you can without stripping the threads.
• Pop your hood, remove the oil cap, and fill your engine with new oil using a filter. Use a dipstick to make sure you’ve added enough oil.
• Put the oil cap back on.

Fuel filter
Kaleebu says it takes about a half an hour to change the fuel filter.
The costs, however will vary depending on your mileage. Here’s how to do it:
• First and foremost, relieve the fuel system pressure by locating the fuel pump fuse on the fuse box. Start your car, leave your engine running, and pull the fuse or relay out. You will know you have done this right if your engine dies.
• After relieving the fuel pressure, you can use two wrenches to disconnect the fuel lines from the fuel filter.
Use a rag to cover the lines after you get the wrenches in place just in case there is still some pressure in the lines. Hold the wrench that is on the filter while turning the other wrench until the bolt comes out.
• Slide the fuel line off the bolt and repeat on the other side.
• Remove the old filter. You may need a flathead screwdriver to do this. Be careful as gas may still be in the old filter.
• On the bolts you removed in steps three and four, there will be washers.
Remove the old washers and replace with new ones.
• Install the new filter by doing the opposite of what you did to remove the old one.
Put the fuel pump or relay back on before you try starting your car.

The numbers

Lowest estimated price of an oil filter for Toyota cars.

Highest estimated price of an oil filter for Toyota cars.

Lowest estimated price of an air filter for Toyota cars.

Highest estimated price of an air filter for Toyota cars.

Lowest estimated price of a petro fuel filter for Toyota cars

Highest estimated price of a petro fuel filter for Toyota cars.