Freeelander 2 TD4 Air Filter

[inside]

My fuel economy has gone up slightly over the last few months. I've done 16000km and thought I'd check the air filter as I assumed they would only change this every few services. The whole filter was covered in black soot and was well past it's used by date. It may be common that this engine needs regular air filter changes but in any case it's 4 hex screws and the new filter is $21. I suggest you check it and change if necessary.

[djhampson]

I just got mine changed over as part of the service and yes it was filthy. $21 isn't bad either.

https://www.aulro.com/afvb/images/imported/2008/10/644.jpghttps://www.aulro.com/afvb/images/imported/2008/10/645.jpg

[beforethevision]

HAHAHAHAH

thats quality!

cheers!

[Dorko]

Do you offroad much?

Is that why its so dirty?
Dorko

[djhampson]

Do you offroad much?

Is that why its so dirty?
Dorko

Yeah I do offroad a bit which I think why it was so dirty. It was also 12 months old when I took that photo.

[inside]

I just got mine changed over as part of the service and yes it was filthy.

:eek: Mine wasn't that bad. Maybe these should be changed every service.

[djhampson]

Strangely tho I haven't noticed a change in fuel economy

[isuzurover]

Air filters can hold quite a lot of dust and still flow a reasonable amount of air.

Contrary to popular belief, filters clean the air BETTER as they load with dust. So it is actually BAD FOR YOUR ENGINE to change the air filter too frequently.

[beforethevision]

Air filters can hold quite a lot of dust and still flow a reasonable amount of air.

Contrary to popular belief, filters clean the air BETTER as they load with dust. So it is actually BAD FOR YOUR ENGINE to change the air filter too frequently.

A dirty filter helps clean the air? perhaps. Flow well? I dont think so.



Cheers!

[Dorko]

:imwithstupid:

Im no Mech, but a dirty filter cant be good in any situation.

Dorko

[isuzurover]

You may want to have a read here:
http://www.aulro.com/afvb/technical-chatter/50650-air-filter-tests-finally.html

But feel free to ignore me. I have only been doing filter R&D for 10 years or so.

Pressure drop across a filter (inversely proportional to airflow) only increases slowly while a filter loads with dust. As noted, those on here who changed a (visually very dusty) filter didn't notice any improvement in fuel economy.

A new filter might remove 90% of the mass of dust reaching it when new, and 99% when dusty, as after a while the captured DUST captures the further influent particles, not the filter fibres. Air filters are NOT sieves. The pores in them are much larger than the particles being captured.

If you read the above tests, you will note that a dusty (donaldson) filter has less pressure drop (flows more air) than an OEM (coopers) filter. So the captured dust has LESS effect than the filter media/construction.

[djhampson]

In your tests the dirty filters had 20km of dusty roads... does this mean 20km or 20,000km?

Because that filter of mine had 24,000km of roads (maybe 5% would have been seriously dusty).

Also I have noticed an improvement in fuel economy... I spoke too soon before. The cars computer calculated L/100km is slow to react but when you calculate it out manually there has been an improvement.

[isuzurover]

In your tests the dirty filters had 20km of dusty roads... does this mean 20km or 20,000km?

Because that filter of mine had 24,000km of roads (maybe 5% would have been seriously dusty).

Also I have noticed an improvement in fuel economy... I spoke too soon before. The cars computer calculated L/100km is slow to react but when you calculate it out manually there has been an improvement.

It says 20k km = 20 000 km. Tdi filters have an integral cyclonic precleaner which removes at least 50% of dust before the filter.

Your filter looked quite black. I suspect it had quite a lot of diesel soot in there. diesel soot is much smaller than road dust, so forms a much more compact filter cake (increasing pressure drop more rapidly)

[djhampson]

Ahh it does too.. I shouldn't try to read things 2 minutes after waking up.. brain wasn't active.

Thanks for the info isuzurover