Air Filter Change Interval?

I am probably the last person on earth to figure this out, but I installed a PD150 Intake yesterday (see my Myth Busting thread in power enhancements) and put in a new airbox top. I pulled the air filter, which had been in the car for almost exactly 20K, and it was more than filthy. Sorry I didn't take a picture. mrchill and PeterV were present and said that VW's recommended 40K air filter change interval is not prudent, that 20K is good, and that others recommend 10K.

I've always been a believer in not exceeding the manufacturer's recommended maintenance intervals, but this has given me pause. PeterV said that 10K for oil and air is good, and that 20K is good for fuel. Cabin twice a year in the Spring and Fall. What do y'all do?

How 'bout 20k miles or 2 yrs., whichever comes first.

I do my air filter every 10k or 15k depending on what OCI I am running. It's cheap insurance, and often it's quite dirty as well. I also change it if I ever open up the box.
Cabin filter: Every 20K (~twice a year for me)
Fuel Filter: Every 20k
-BB

AF change

I used to check mine at least as often as I changed the oil and found it to be nasty after 10k here in the high desert of Reno, NV. Adopted that as a good distance for changing it in this environment.

I have changed mine at 20k. Both times the air filer looked very good. I don't know that i would want to extend it, but 20k looked good. I drew up my maint. excel sheet based on the book and i think it lists 20k air filter change.?. Mine is an 05 a4. Maybe they did change it. Will have to look when i get home.

Is my memory that shot?

I thought it was 40K for the air filter according to both the OM and the RB manual.

A paper filter that's a bit dirty should filter better, as long as it's not restricting too much airflow.
Didn't DBW say that his airbox meter was showing no significant restriction after 40K miles?
20K for cabin and FF.

on edit

Looky here!
World Impex 20K service kit includes only FF, cabin, and oil filter for BRM. I don't think ALH or BEW is any more stringent.

i've did mine at 25k seemed pretty dirty but should have been fine i'm guessing till 40k. i think it just really depends on your driving environments. i'm probably going to stick with ~30k for my air filters..

Yes, manufacturer does say 40K. But at 20K my filter was more than dirty, and wet to boot. Lots of sand in the bottom of the airbox. I've now got an R32 DSG airbox in there with a filter with a cold climate layer. I feel better.

Usually won't go wrong following DBW's advice

Here's some thoughts DBW had on the matter back in '03.

Drivbiwire said:

A VW intake even with 60,000 miles on the filter shows no measurable restriction even at full boost with a chip running 18psi.
The restriction was measured to be about .5" water pressure differential accross the OEM paper filter, in other words there is virtually no restriction at all.

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I understand there may be conditions where a 40K interval is too long.

If you are driving in a particularly dusty and nasty environment, I'd put a filter meter (gauge) on the airbox so you know what's going on.

I use the cold climate filter and if it has a good seal, I leave it alone for 40K miles or 2 years.

If you change a fuel filter at 20k to prevent damaging a very expensive pump, wouldn't it be cheap insurance to change the air filter at the same time to prevent sand from entering a far more expensive cylinder block? It's so easy to do I don't understand-- why mess with the dirty filter doing a better job theory?

Souzafone said:

If you change a fuel filter at 20k to prevent damaging a very expensive pump, wouldn't it be cheap insurance to change the air filter at the same time to prevent sand from entering a far more expensive cylinder block? It's so easy to do I don't understand-- why mess with the dirty filter doing a better job theory?

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Firstly, I wouldn't be so sure it's just a theory.

Secondly, and independently, there have been some UOAs that show decreased Silicon contaminant rates, as the interval increases. It may take a while for the new air filter to make it's best seal.

In short, if you have a good seal, and no evidence of excessive restriction, it's cheap insurance to leave a well-sealed filter in place until the recommended 40K change interval.

/beating a dead horse

spoilsport said:

A paper filter that's a bit dirty should filter better, as long as it's not restricting too much airflow.
Didn't DBW say that his airbox meter was showing no significant restriction after 40K miles?
20K for cabin and FF.

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I've been rethinking my air filter intervals here recently and I think the above seems like sound advice.

Any high milers want to chime in on your routines?

I've been doing every other oil change...which is 20k miles. Maybe I should just drive more and worry less....

Old thread! I do change at 20K intervals now. But what I also did recently when replacing my airbox was switch to a filter with prefilter. cevans said I should use it since I don't have a snow screen. My car has a lot of intake noise with the PD intake and it is a bit quieter, fwiw.

Here's my air filter after 20K. Note that the plastic stiffeners failed and the pieces were sucked into the turbo. This was a German air filter and just lots of highway driving.

I have installed a filter minder like this one: http://www.amazon.com/85-2444-Filter-Minder-Screw/dp/B000E5XQDO/ref=pd_sim_auto_1 With this is place you can monitor the condition of the filter. You install it and then go for a spirited ride to set the new filter pressure differential; then you look at it from time to time and then you know when to change it.

When I lived in Augusta GA where the pines dump piles of pollen into the air, my gauge went from normal to pegged in one day!

IndigoBlueWagon said:

Old thread! I do change at 20K intervals now. But what I also did recently when replacing my airbox was switch to a filter with prefilter. cevans said I should use it since I don't have a snow screen. My car has a lot of intake noise with the PD intake and it is a bit quieter, fwiw.

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Yup...it is an old thread, but I didn't want to start a new one.

My Golf still has the snow screen...which I clean every 10k. Plus, I've always used the Mann cold weather filter with the prescreen.

I think I may get one of those filter minders and monitor it. I've noticed my filters at 20k don't 'appear' to be dirty at all. However, all I do is interstate driving so it doesn't take me long at all to rack the miles up.

Chris, How is it installed?

romad said:

Chris, How is it installed?

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I have one like this: http://www.amazon.com/Wix-24801-Air..._3?s=automotive&ie=UTF8&qid=1324670322&sr=1-3

Installation is pretty self-explanatory. Drill a hole in the airbox top, insert the grommet, shove the filter minder into the grommet.

Oh yeah. Hopefully I don't really have to add this, but take the airbox top off before drilling the hole. Plastic shavings aren't all that good for turbos and engines.

Interesting. I thought it would be installed after the filter so the pressure differential can be measured. If this is installed in the top, isn't that before the filter? How can it work?

romad said:

Interesting. I thought it would be installed after the filter so the pressure differential can be measured. If this is installed in the top, isn't that before the filter? How can it work?

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Nope, that'd be after the filter.

Filter on a 6.0 Ford:



Open it up to see:



The filter minder hadn't moved. I can apply a vacuum and it will move.

Unknown mileage on the filter.