Just had my 2005 F250 a few weeks and the 'check air filter' warning came on
Checked the filter, it looks fine, hasn't come off...it's the cylindrical one.
Anyone have an idea what's wrong?

 

What motor do you have in your truck?

Does it have a filter minder?

If so, what does it say?

 

Had to look filter minder up...by golly it does and it's pushed all the way yellow.
So you mean I can't just LOOK at a filter any more to see if it's dirty, they can be dirty
without looking dirty eh? It's a 6.0L Diesel btw.
Guess that's it. Thanks.
Seen anymore cougars? Better be packing son. Maybe they're clearing all the liberals outta BlueGrass country.
Just bought me a S&W Bloodworks .44 mag, 629pc.

 

If you have the stock filter, I don't know how you could look through a foot of filter media to see if it's dirty or not. They last 60-90k pretty easily, so you could just punch the filter minder and see if it pops again.

If you have a replacement fake-CAI, the mider doesn't matter anyways, just reset it.

 

Well I'm still learning Texas...back in the old days you could look at a filter and it looked dirty as can be, you could tell, maybe today you can't? My real first diesel here...how could that yellow thing get pushed all the way with it not being dirty? Ok, per your suggestion I popped it, and it went down...will go for a test drive now, see if that did the trick.

edit: back from drive. No message now. So I may have a fake minder that pops full yellow but that doesn't matter anyway? It can give a false reading when I don't need a new filter? Dam ISIS must be selling those.
I have 118,000 miles...then it could be the original filter? The yellow WAS entering the red line btw...so I need a new filter now? I think one's about $40? Back when I was driving my first car, '72 Monte Carlo, you could go to Ben Franklin or the like and buy a filter for $10.

 

The minder is a vacuum idiot switch, nothing more, so the increments on the gauge aren't really important. If the turbo is pulling air faster than the filter can flow it, the pressure drops and the switch pops. It's not a reliable measure of anything specific really, just an indicator that flow through the filter isn't enough, so it's "dirty" and replace it. I do the air filter every 30k (3 years on average) because it's easy, I write the date/milage on top with a white paint pen. Some people leave them in until the thingy pops, normally complaining it's $40 wasted to change the filter before the deal tells you to. Oil changes cost me about $90 every 5k, so I don't care about $40 every 3 years to not have to mess with this problem.

Check the filter and if it has white media, replace it no matter what. If it's blue media, I'd replace it now so you know when it was done last and leave it in there for 30-50k miles. Correct filter:
https://www.dieselfiltersonline.com/...c3z9601aa.html

Popping the switch constantly at WOT can sometimes indicate stuck VGT vanes on the exhaust side of the turbo causing over-boost. So if the filter minder sets every time you mash the pedal, you need to check the turbo. Replace the switch before cracking the turbo open, because it's easy to break the plastic and make it worthless anyways. I've seen several truck where the grommet and minder was replaced with a solid grommet and the minder sat loose behind the intake, because if you can see boost on a gauge and change the filter regularly, the entire sensor is redundant.

 

Thanks. I'll replace the filter; it was kinda blue/grey.

 

I haven't seen any more of that cat, but a neighbor saw one back over the summer that was black. So, while the Dept. of Fish and Wildlife say they don't exist, a few folks have seen them.

And Bryan's got you taken care of on the air filter. It's a completely different design than what most people are used to. They do a great job of filtering, and, they allow a considerable amount of air for their size compared to the typical filter you're used to seeing.

 

Yeah, turns out it's an after market filter, I round cylindrical one...the po had put in some new fangled air intake system...so every jack leg around here didn't have the filter, would have to order it. One sold me a new rect. filter, another wanted to order me one, and one told me the filter I had now wasn't too bad, that it'd probably do for a while and would do a better job filtering now than a brand new one would.

 

Can you take a picture of your intake and post it here? From reading on FTE the OEM 6.0l intake is good for 500hp.

 

It says AFE Power on the airtake system... looks a bit like this
https://ixquick-proxy.com/do/show_pi...200391ccac352e
or this https://ixquick-proxy.com/do/show_pi...41c8da9769dea2
but not exactly; there are 6 hex screws holding the rectangular lid on. My camera is slow, I took a photo but it downloads very slowly.

 

Here's actual photo: <a href="http://s301.photobucket.com/user/DavyKOTWF/media/Katanas/SAM_1868_zpsvfrpmkpa.jpg.html" target="_blank"><img src="http://i301.photobucket.com/albums/nn44/DavyKOTWF/Katanas/SAM_1868_zpsvfrpmkpa.jpg" border="0" alt=" photo SAM_1868_zpsvfrpmkpa.jpg"/></a>

 

That is a washable filter u have there, just clean it let it air dry and reinstall

 

Will do, thanks SDS.

 

No problem. And whats that all over the motor compartment, salt?