Back To Basics: Pollen filters

Rob Hawkins outlines what’s involved in renewing the cabin or pollen filter on most vehicles.

Avehicle’s cabin or pollen filter is designed to remove dirt and, as its name suggests, pollen from entering the interior via the heater or air-conditioning system. Most filters consist of a disposable paper element panel, located close to the heater matrix. In many cases, they can be accessed via the passenger footwell or sometimes the nearside scuttle panel area of the engine bay.

The filter is often neglected during an engine service, which can result in a number of problems. The interior and heater or air-conditioning system can start to smell, for example, because the filter is no longer effective and is allowing all the dirt it has collected to be drawn into the cabin. If the filter is particularly clogged, it may restrict the draw of fresh air and put a strain on the motor that has to circulate the air. And in some cases, the area around the filter can become blocked with dirt and flooded with rainwater, resulting in failure of components nearby.

One of the reasons for failing to renew the pollen filter is due to lack of knowledge. They can be awkward to access and fiddly to extract. In some cases, the glovebox has to be removed, or the windscreen wipers and scuttle trim panel, which not only makes the job time-consuming but potentially creates more problems – such as the windscreen wipers seizing onto their spindles.

We’ve seen plenty of CM project vehicles and our own cars have a filthylooking cabin or pollen filter despite an up-to-date service history, suggesting the filter hasn’t been renewed as often as it should have. The following pages outline the general steps involved in renewing these filters, and have been split into two categories – glovebox filters and scuttle panel filters.