Air filters Logically, Blue Print highlights that ineffectual air filtration has ramifications for the oil filter, too. Aside from abrasive particles passing through the air intake and damaging the piston/rings, cylinder walls and valves, they can end up in the crankcase. It is also mind-boggling to think how much air passes through a typical air filter throughout its lifetime, especially with turbocharged engines. Blue Print reports that an air filter on a 1.6-litre 2012 Nissan Qashqai would have filtered 40 million litres of air by the time it reached its recommended 37,000 miles replacement interval.
Even so, you may discover an excessively dirty air filter that has not reached its official renewal mileage. Trust your instincts and advise the customer. First Line finds that some car owners resist replacing air filters, because the car has not covered sufficient miles. This means that you will need to make the case that virtually every car manufacturer recommends more frequent air filter replacement, dependent on atmospheric conditions. Aside from poor engine running and difficult starting, make a case for economy: a clogged air filter increases fuel consumption and emissions. In addition, air filter condition is one of the primary initial checks that informed garages make, when investigating DPF blockage causes. The relative ease of replacing air filters can lure technicians into a false security; mistakes still happen. UFI reminds us that not ensuring that its foam edges seal correctly in the housing can affect the filtration ability, as well as causing a noise. After you extract an old filter, even if it is to be refitted, remove any larger particles from the housing, such as leaves. Consider also that engines prefer to inhale colder, denser air. Therefore, ensure that any ducts, leading to the car's front, are connected to the airbox. This may lead you to advise performance air filter enthusiasts to reinstate any removed air filter housings and associated pipework, because it could make the engine run better. Interestingly, UFI highlights that cleaning standard filter pleats with compressed air is inadvisable, because doing so increases the material's porosity, therefore compromising its filtration abilities.
FILTERS
Petrol filters
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As many petrol cars do not possess fuel filters, it is easy to overlook the models that have them fitted. First Line adds that replacement can be deemed incorrectly as an unnecessary expense. Yet, the recent introduction of E10 petrol is confronting petrol filtration with new challenges. As ethanol is an effective cleaner, it can loosen residual petroleum deposits
(such as gums) within the fuel tank, enhancing the risk of them being introduced to the fuel injectors. Therefore, should you be confronted with a car that possesses a replaceable petrol filter, consider advising the owner to have it replaced as soon as possible. Many of these units tend to be slung beneath the car, exposing them to moisture and road salt. The unions are vulnerable to corrosion, too, particularly if the filter is overdue for replacement. As these metal unions can incorporate the entire fuel line, breaking them is clearly undesirable, so work carefully. Even so, quality manufacturers protect petrol filters, by either making them from plastic, or painting the canister in anti-corrosion paint. Yet, consider that the coating will be compromised, should the filter body rub against any surrounding metal parts. Ensure, therefore, that any plastic, or rubber, mountings are intact and refitted correctly. When fitting a replacement, most types tend to be directional; a printed arrow on the filter body tends to indicate the flow path from the tank to the engine, not vice versa. Especially as E10 petrol increases the risk of fuel system blockages, garages need to suspect the fuel filter, should they encounter a petrol car with engine running issues and low fuel pressure faults. Typical symptoms include difficult starting and power losses, because the quantity of fuel delivered is lower than that requested by the engine. Blocked injectors and engine stalling are further consequences. MEYLE emphasises the importance of buying quality, elaborating that it has found low-quality filters to be so bad that the fuel is not even filtered after passing through the canister, making the quality argument even more relevant.
"Especially as E10 petrol increases the risk of fuel system blockages, garages need to suspect the fuel filter, should they encounter a petrol car with engine running issues and low pressure faults"
