# Air Filter



## MP81 (Jul 20, 2015)

When our CTD was at the dealer getting the oil changed (because I haven't decided on which full-synthetic to use, and it was also a time crunch - and its $40 for Dexos2) and having the latest recall fix performed, they also called me to tell me about the air filter and that is was "Dirty. Like, really dirty". They understood me not wanting to pay them to install a new one, but I also thought they might just be over-exaggerating - especially since the car is just over 50k miles. 

Sunday night I popped the hood, and removed the 35,000 screws that hold the airbox together, and lo and behold, the air filter is pretty **** dirty. Not the paper, but the "foam" on the bottom, is practically black. So they weren't lying, or talking it up to get another sale (good points for our service dealer, which we've been happy with thus far), but it definitely surprised me with how dirty it was for the mileage. I'm used to replacing filters at far longer intervals and still not having them be that dirty.

Must be the foam catching smaller particles first (along with bigger ones)? Anybody else notice the same? 

Ordered a new Delco filter yesterday, should be here Friday. Maybe we'll even see a small increase in fuel economy if all that dirt in the foam is causing a decrease in breathing ability.


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## jblackburn (Apr 14, 2012)

Yeah the foam on the filter on my 1.4 was very dirty @ 40k. The paper filter underneath was otherwise fine.


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## MP81 (Jul 20, 2015)

jblackburn said:


> Yeah the foam on the filter on my 1.4 was very dirty @ 40k. The paper filter underneath was otherwise fine.


I'm sure it helps for filtration, but sure seems like it makes a filter that would normally be considered clean, dirty and in need of replacement. Did you just replace the filter then?


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## IndyDiesel (May 24, 2015)

50k miles for a air filter seems like a long interval, if the filter is dirty that is dirt that didn't make into engine which is a great thing.


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## jblackburn (Apr 14, 2012)

MP81 said:


> I'm sure it helps for filtration, but sure seems like it makes a filter that would normally be considered clean, dirty and in need of replacement. Did you just replace the filter then?


My car was ~ 4 years old at the time, so I'd already ordered one as basic maintenance I was doing. I went ahead and changed it out.

I think part of the purpose of the foam on there is also to dampen intake noise - to isolate that turbo "whistle" as much as possible.


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## MP81 (Jul 20, 2015)

jblackburn said:


> My car was ~ 4 years old at the time, so I'd already ordered one as basic maintenance I was doing. I went ahead and changed it out.
> 
> I think part of the purpose of the foam on there is also to dampen intake noise - to isolate that turbo "whistle" as much as possible.


Ahh yes, didn't even think about that. Too bad it does not come off, or if it does - not easily. 

Ours is only about 2.5 years old right now, but for $10, I'd rather not have the foam filled with dirt causing any kind of fuel mileage decrease.


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## BU54 (Nov 24, 2014)

Is the gasoline filter the same? I haven't changed mine yet but plan to during Christmas vacation.
Also how much do they cost?
Thanks!


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## MP81 (Jul 20, 2015)

IndyDiesel said:


> 50k miles for a air filter seems like a long interval, if the filter is dirty that is dirt that didn't make into engine which is a great thing.


I guess that is the typical re-oiling interval for a K&N filter. Thing is, the filter (paper) itself wasn't dirty, just the foam. If that foam is there to quiet the intact tract down, then it likely doesn't do a ton for filtration, it just gets dirtier first, which would impact flow.



BU54 said:


> Is the gasoline filter the same? I haven't changed mine yet but plan to during Christmas vacation.
> Also how much do they cost?
> Thanks!


Yup, same filter. The Delco one is about $11 on RockAuto.


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## spacedout (Dec 7, 2010)

IndyDiesel said:


> 50k miles for a air filter seems like a long interval, if the filter is dirty that is dirt that didn't make into engine which is a great thing.



Look at the size of the filter, its much larger than needed for an engine of this size, that's the reason its perfectly ok to run for longer mileage since it has much more filtering capacity. I suspect even dirty it flow more than a 2.0L or under engine would ever need. The air filter in my 3800 engines was half the size of the cruze, Cruze filter is almost as large as some of the 10 year old V8 engines. 

I got in the habit of changing my air filter every fall the same time I changed the cabin filter(around every 25K). buying the parts online its cheaper doing both yourself than even one filter would cost at the dealer.


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## IndyDiesel (May 24, 2015)

I just check the air filter periodically to determine if it's dirty, owners manual states to change it at 45k miles.


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## diesel (Jun 8, 2013)

I change mine every 35K-40K miles and they are very dirty. I hold them up to a light, and can't see the light through the filter. When I put a new one in, the car has noticeably more power.


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## Chris Tobin (Feb 23, 2016)

diesel said:


> I change mine every 35K-40K miles and they are very dirty. I hold them up to a light, and can't see the light through the filter. When I put a new one in, the car has noticeably more power.


If you are noticing a power difference, it is restricting the incoming airflow and you are waiting too long!!! IMHO


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## Snipesy (Dec 7, 2015)

My amsoil filter was no longer a nice bright blue after 4K miles....


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## diesel (Jun 8, 2013)

Chris Tobin said:


> If you are noticing a power difference, it is restricting the incoming airflow and you are waiting too long!!! IMHO


Good point. I should adjust my interval down a bit.


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## MP81 (Jul 20, 2015)

Changed it over this weekend while it was "warm" (20) out. We're driving down to Atlanta this weekend, so I definitely wanted it in there for that. Haven't gotten fuel yet to tell if there's a difference or not - probably won't notice so much on this tank with all the remote starting and super cold weather (just finally not frigid yesterday afternoon and on). 

The picture definitely makes it a little darker than it really was, but it certainly was not clean. 

Wonder if removing that "foam" would increase filter flow and longevity, as well as increase turbo noise...


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## diesel (Jun 8, 2013)

MP81 said:


> Wonder if removing that "foam" would increase filter flow and longevity, as well as increase turbo noise...


Probably both... and allow more dirt in as well. Always a tradeoff.


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## MP81 (Jul 20, 2015)

diesel said:


> Probably both... and allow more dirt in as well. Always a tradeoff.


Well the paper should then take over as the filtering element, like it does on "normal" filters. The foam won't catch finer stuff anyway, the paper does.

It's adhered pretty well, so I'm not going to bother removing it - maybe I should've kept the old one to "experiment" on.


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## ssnscruzeeco2015 (Dec 29, 2014)

I got around 50 thousand miles on mine but also have a filter monitor installed. Right now it is only reading 5 inches of water or 50% full scale. That reading was taken after a recent full power trial (nearly 800 CFM of air measured). I think the 6 plus 90 degree bends in the tubing are more restrictive.


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## diesel (Jun 8, 2013)

ssnscruzeeco2015 said:


> I got around 50 thousand miles on mine but also have a filter monitor installed. Right now it is only reading 5 inches of water or 50% full scale. That reading was taken after a recent full power trial (nearly 800 CFM of air measured). I think the 6 plus 90 degree bends in the tubing are more restrictive.


How does the monitor work? Have any pics?


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## jsusanka (Jan 31, 2011)

I changed my air filter around 30,000 at three years. I am just going to change it every three years and the cabin every two years regardless of mileage. So next year both are due for me and it will be my second air filter and third cabin filter. My air filter at three years was pretty clean. That is fine with me keep it like new cheap maintenance to keep the problems away (hopefully). Just easier for me to remember since I am getting old and feeble.


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## justin13703 (May 2, 2016)

Removing the foam and the intake joint right where it goes down through the fender do give a little more turbo noise but not much. There is a thread on here somewhere about doing that.

Removing the foam won't allow more dirt into the engine. The foam is very course and just catches the big stuff. That same stuff will get caught with the paper filter, not having the foam there will just cause the paper filter to get dirtier quicker.


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## Gator (Jul 14, 2013)

Do not remove the foam it keeps moisture out of the turbo.


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## Merc6 (Jun 8, 2013)

I removed the foam on the oem one and all the filters I replaced it with also didn't have it. Is there something special about the Diesel that it got that dirty? My gasser never ever got that dirty and I been in some construction site like areas and tons of miles turnpiking it with an airbox full of holes to make turbo noises louder. I changed it out yearly while the cabin went spring and fall. Very last bit of ownership I went K&N panel as it came with my spare air box just to see if noise was similar as STP paper. K&N and foam delete wasn't that much difference sound wise.


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## diesel (Jun 8, 2013)

Merc6 said:


> I removed the foam on the oem one and all the filters I replaced it with also didn't have it. Is there something special about the Diesel that it got that dirty? My gasser never ever got that dirty and I been in some construction site like areas and tons of miles turnpiking it with an airbox full of holes to make turbo noises louder. I changed it out yearly while the cabin went spring and fall. Very last bit of ownership I went K&N panel as it came with my spare air box just to see if noise was similar as STP paper. K&N and foam delete wasn't that much difference sound wise.


Come to think of it, I've never seen a filter get this dirty in a gas car either. Maybe it requires more air?


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## MP81 (Jul 20, 2015)

diesel said:


> Come to think of it, I've never seen a filter get this dirty in a gas car either. Maybe it requires more air?


It shouldn't take any more air in than, say, a gas 2.0L turbo. It just compresses it more, but that's all done with likely a similar air volume. 

That is why I was surprised at how dirty it was - I've let filters go on larger N/A gas engines for much longer, and they've been far cleaner. I would say the foam definitely makes it look dirtier than it actually is, though.


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## diesel (Jun 8, 2013)

MP81 said:


> I would say the foam definitely makes it look dirtier than it actually is, though.


That makes sense. Same dirt over less surface area, basically.


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## ssnscruzeeco2015 (Dec 29, 2014)

diesel said:


> How does the monitor work? Have any pics?


It is a very simple display type of pressure deferential gauge between atmosphere and intake system vacuum, across the filter media.


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## diesel (Jun 8, 2013)

ssnscruzeeco2015 said:


> It is a very simple display type of pressure deferential gauge between atmosphere and intake system vacuum, across the filter media.


Interesting!


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## BlueTopaz (Aug 25, 2012)

I'm one of those money wasters. I change out the air filters every 20k miles. They are dirty but not real bad. With all the pine trees around us, that yellow pollen gets really bad in the spring and you can see it on the filters.


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## pandrad61 (Jul 8, 2015)

> Changed it over this weekend while it was "warm" (20) out. We're driving down to Atlanta this weekend, so I definitely wanted it in there for that. Haven't gotten fuel yet to tell if there's a difference or not - probably won't notice so much on this tank with all the remote starting and super cold weather (just finally not frigid yesterday afternoon and on).
> 
> The picture definitely makes it a little darker than it really was, but it certainly was not clean.
> 
> Wonder if removing that "foam" would increase filter flow and longevity, as well as increase turbo noise...


in the menu did you make it so when you remote start the seat warmers turn on too?


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## pandrad61 (Jul 8, 2015)

> It is a very simple display type of pressure deferential gauge between atmosphere and intake system vacuum, across the filter media.


i like ford has those stock


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