Replace pollen filter with kitchen roll

do you have air conditioning in the car? If so then you really need the pollen filter, it keeps crap from collecting on the evaporator, which then smells , and blocks the airflow. A pollen filter is such a minor expense it would be pointles to try to economise. If you have no air con then the above does not apply, but a pollen filter does keep the inside of the car much cleaner and catches at least some of the diesel particulates which are not very good for your health.

Air filters are often *not* symmetrical. The side the dirty air hits first has larger holes, so that the bigger particles are trapped there. This extends the filter life because it increases the time before the finer, downstream side blocks.

HVAC filters, and those for things like electrical control panels are usually multi-layered in this way.

I don't know about the Corolla, but many cars use the airstream entering the heating system to cool the fan speed resistors, and if the filter is blocked the resistor bank may burn out.

If you are looking to keep the car for more than a few months, it would be unwise to try to economise on the cabin filter. If you really can't afford a new one, it would be better to try to clean the old one, either carefully using an air line against the direction of flow, or with a vacuum cleaner.

There is no way that kitchen roll would be effective as a filter!

Chris

If the kitchen roll shreds, you will have a major dismantling job on your hands.

Think pollen filter only means that is the finest particles it removes. It also stops half bricks being blown into your eyes. ;-)

The two on my BMW are very easy to get at so I give them a hoover once in a while, as they're quite expensive. Since doing that they've never blocked.

One thing that a pollen filter singularly does not do, is prevent hayfever.

"Dave West" wrote

I don't understand the point of the filter either (certainly not a carbon loaded one). Old cars used to have a box and labyrinth to catch the large stuff so I guess manufacturers saw business in getting rid of that and selling something with a large mark up.

At a minimum, it might be better to use aluminium mesh (Halfords body filler section) to catch bits. If the old filter has a plastic frame, cut the element out and hot glue the mesh in place.

Which doesn't mean it's not necessary, of course.

Modern cars use heater matrices that are much smaller, yet more efficient, than in the past. They are more prone to being blocked due to the reduced distance between the fins.

Cars generally have a lifespan (in mileage terms) an order of magnitude greater than formally; the matrix is therefore likely to experience much greater exposure to dirt.

The difficulties of not having a filter will be doubled if the vehicle has A/C.

An average filter change interval is usually three years, and a filter might be 10 quid. In terms of running costs, and any potential profit to the manufacturer, that's pretty damn trivial!

I noticed that the first car that I owned with a cabin filter stayed very much cleaner inside, and I would be happy to pay the tiny amount of extra cost for that reason alone.

Chris

I do find it amazing that anyone who can afford to tax, fuel, and insure a car would even consider it, unless the cabin filter is *really* expensive: typically, as Chris says, it's f*ck all cost.

If your meaning of "efficiency" is that it has a larger surface area to volume, that may be so. Doesn't mean that the change in airflow so caused - to bring the required amount of energy into the cabin - is necessarily better for comfort. (If my present car is anything to go by, it is the worst H&V I have ever had.)

Oh certainly, but redesign to make a smaller system with filter probably allowed a cost saving on the assembly line. Usually a good motivator.

I have owned several cars beyond their 10th year. Can't say I've noticed a particular problem. Most dirt is brought in on shoes.

The principle is that manufacturers have added something of questionable value. At what point does a collection of insignificant items turn into something significant?

Finally gave up on 'official' BMW service when they changed the pollen filters when neither scheduled or needed. They cost about 40 quid so worth arguing over.

I don't think it's of questionable value, having seen the s**te on mine when changing, and, unscientifically, I reckon I have to clean the inside of the windscreen less than with any of my cars that didn't have one.

The manufacturers are under pressure to make service costs seem low, so I don't think they'd introduce something with no value. I'd certainly say the cost of a cabin filter every 20 or 40k miles is totally insignificant compared to the other costs- even the other service costs. Looking at my car's service schedule, I really don't see anything that gets changed that is worthless.

FFS, buy non-genuine and it's less than a gallon of fuel:

My system has climate control so I had to devise a way to nobble it. One of my extra temperature sensors rests on top of the filter to measure incoming air. So a second reason for instructing service people to leave the filter alone.

Have you ever had sex? With a woman, that is...

If it wasn't for generations of men that didn't have sex you would be sleeping under a tree, sharing raw meat your tribe had to catch with their bare hands. "Oh, look at moron just sitting there rubbing sticks together. Let's go and beat him up."

heh