Latest News:

autotechnician - serving the independent workshop - logo

Filters – Prevention is better than cure

If servicing is being skipped, surely filtration sales would have plummeted? Rob Marshall asks around and discovers the consequences of cutting filtration costs.

When looking at whether, or not, aftermarket servicing is being skipped by drivers, we asked filtration manufacturers if they have detected a shift in the British market. On the surface, it seems as though the research is not reflected in real life. For instance, Mahle UK reports that it had a strong 2023 and its market share continues to increase. First Line says that its filter sales are also up, while UFI has achieved double-digit growth in the last twelve months.

Yet, this is not to say that motorists are not shaving costs. Mahle UK elaborates that it has seen shifting trends. It says that certain filters are either being replaced less often, or with lower-quality equivalents. The company warns that both moves are a false economy, because they risk costly repairs in the medium to longer terms. Delphi highlights that using sub-standard parts means that workshops risk customer complaints and even extra remedial work to remedy any subsequent faults that may arise. The ultimate message is that low-quality components can cost garages money.

What are the consequences?

Delaying filtration replacements, or using inferior replacements, can cause damage, in terms of either reduced component life, or even a breakdown. While many garages are (justifiably) wary of VM-set extended oil drain intervals, filter manufacturers share the same concerns about the element. UFI is one such manufacturer that recommends that the oil filter be replaced more frequently than the official service interval states, for instance. An oil filter that becomes clogged should typically, activate a bypass function, meaning that dirty, untreated lubricant will be fed to the vital engine components. While undesirable, at least this situation is better than a complete collapse of oil pressure! Furthermore, low-quality filters may not be fitted with an anti-drain valve, causing oil starvation
on start-up, which tends to be the point of engine operation, where most wear occurs. UFI also emphasises the importance of ensuring that the correct filter is fitted as per the catalogue recommendation. It explains that fitting a filter to the wrong engine can cause an internal malfunction, such as element collapse.

UFI says that, although filters look very similar from the outside, the performance of any filter (e.g. pressure control, quantity and type of filter medium used, leakage protection, sealing material, etc.) can deviate enormously.

With most air filters being relatively straightforward and inexpensive to replace, it is hard to think of a reason why they are neglected. Yet, they can be. Delphi explains that, because engine air filters trap dirt, dust, and debris, preventing them from entering the engine’s combustion chamber, failure to replace the filter restricts airflow. While modern fuel systems can adjust fuel trim to an extent, more fuel tends to be burnt to maintain performance, leading to decreased fuel economy. Mahle also explains that this reduced airflow can damage not just the air mass sensor but also engine valves and even sensors in the exhaust system. UFI adds that higher exhaust emissions are also symptoms but the filtration expert explains that visual checks are straightforward. Evidence includes extreme quantities of dirt, leaves, mould and dust being present within the filter and its housing. Look also for damage, such as collapsed pleats, or poor sealing between the filter element and the edges, which point to poor filter build quality.

Being a developer and supplier of filters for car makers, UFI advises that the latest high-pressure diesel engines tend to be considerably less forgiving of poor, or neglected, fuel filter changes. It highlights that even a small particle of grit can damage the high-pressure fuel pump and injectors severely. Not only should routine diesel filter replacement be essential, but technicians must be vigilant to ensure that no foreign matter is allowed to enter the fuel system. First Line says that a clogged fuel filter introduces a resistance that prevents fuel from passing through it, causing fuel starvation. Delphi adds that the insufficient fuel supply causes engine misfires, rough idling, and hesitation during acceleration. This may also trigger an engine management code but beware of being sidetracked into suspecting more expensive components, when the fuel filter alone may be the culprit.

Aside from OE quality, never deviate from the OEM installation instructions.

While many automatic and twin-clutch automated manual gearboxes contain non-replaceable magnetic filters, some of them (including rear drive couplings, such as certain Haldex systems) possess renewable filters. Delphi reports that these parts help to prevent the fluid’s integrity from being compromised. Furthermore, abrasive particles that circulate in the transmission fluid can accelerate wear on gears, bearings, and seals, leading ultimately to transmission failure. First Line adds that a clogged transmission can cause shifting issues. Therefore, whenever the fluid is replaced, change the filter. Should you have to tear down a transmission, ensure that any internal filters are also cleaned thoroughly.

A cabin filter is a prime area where a driver may look to cut a servicing cost. UFI recommends, however, that the driver be quizzed about not just allergy symptoms but also fatigue and poor concentration while driving. Further evidence of a cabin filter that is ripe for renewal includes unpleasant odours, pollen particulates within the cabin, or even persistent fogging of the windscreen and side windows.

Communication is key…

Mahle UK appreciates that garages still need to be competitive. Yet, the main thing is to talk to your customers. Explain to them why OE Quality components are important, with demonstrations preferably, to highlight what they are getting for their money. This may mean that reception staff require extra training support to give them the confidence to communicate the importance of quality filtration. Delphi also reminds us that not fitting OEM parts will void warranties.

Heed the torque figures, especially for plastic-capped filter housings, which can be damaged easily by overtightening.

While it admits that counterfeit parts have been an issue for a long time, Mahle reminds garages that they are liable for any component that its technicians install, regardless of who supplied it. Should that part fail and cause damage, Mahle says that the garage is responsible, no matter what disclaimer is added to the invoice. As the fitter is deemed to be the expert, not being in control of your parts could be detrimental not only to the vehicles within your workshop but the garage itself.

About Autotechnician
Autotechnician is a magazine published nine times a year, delivering essential information to independent garage owners and technicians in the UK. Delivered both digitally and in print, autotechnician provides readers with technical, training, business advice, product and news, allowing our readers to keep up to date with information they need to run and work within a modern workshop.
Aftermarket Media Solutions Ltd, The Joiners Shop, Historic Dockyard Chatham, Kent ME4 4TZ
T: 01634 816 165
Company no. 09625886
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram