GrimmSpeed Air Oil Separator (AOS) Install

[@Lysol_kb]

im astonished that this is such an easy follow-through design for an AOS. def gonna be installing this on my 2011 sti

[@ijumpshot2613]

Thanks for the vid. Made the install too easy. I ended up running the pcv valve hole straight to the separator and still had two foot of hose left.

[@cdirks3304]

I've had this on my Forester STI conversion for about 2 1/2 years now, and I just purchased it for my 13 STI. Great product, great customer service, great company! Thanks for doing what you do for the Subaru community Grimmspeed! Look forward to getting your TMIC in the future!

[@GrimmSpeed]

@e85junkie Great question! You will fin water collect in a catch can because it has a direct "open line" to the atmosphere. When metal gets cold water will condensate on the surface and over time collect. This can be apparent on short trips or cold weather where the condensation is not given enough heat to fully evaporate. The water would never make it all the way into your motor because it would evaporate before getting there. What is unique about our AOS though is that the OEM operation stays!

[@xhunter909]

I just wish you had the rebuild kits in stock. I ordered mine like 2 months ago.

[@andreweverett1218]

I just bought this for my sti!!! Im so excited for it, 4 days until its delivered!

[@matthomes9486]

Yes you will have to use a 19mm socket to remove the core to add oil. Your stock lug nut wrench just so happens to be a 19mm so you will always have the means to do with with you. -Matt Homes

[@hellsbaby127]

When an engine burns fuel it produces condensation, if you only do short journeys the engine/exhaust will not get hot enough to burn it off. Hence emulsification in your oil filler cap and breather hoses, and eventually premature death to engine and exhaust. Your oil won't reach temperature and your pistols won't fully seal etc etc. If you love it then use it, otherwise walk.

[@GrimmSpeed]

;-) We try to have a little fun with these videos when the opportunity presents itself! -Matt Homes

[@sganet_]

Please do and make an installation video, because our GTs have a different turbo/intake setup then the rest.

[@igorushka]

Installed it on 2006 outback xt. It took some effort to install the last hose, but it is well worth it, now XT even got better gas mileage and a pace of mind that subie will not have ring land failure.

[@06wrxRAR]

i have it on my 06 wrx and i have noticed 1mpg improvement. yes even 1 mpg is noticeable when it adds up in trips and cobb accessport display. the shifter also gives vibrations of the engine detonation. this is with group N bushings all over so the feeling is sharp. the engine idles a bit smoother. the top mount intercooler doesn't have much oil like default OEM setup. so that means it helps with detonation characteristics as well. product is worth the money. thank you grimmreaperspeed can you make a special color for me, gold AOS?

[@GrimmSpeed]

Simon, There are shorter aftermarket oil filler necks you can get, and some with a different angle to accommodate FMIC piping. The names of the manufacturers are evading me at the moment but I am sure with some searching they will pope up. We do not make a AOS unit that is any shorter, so reducing the filler neck length will be the easiest option. -Matt Homes

[@crashboy40]

@GrimmSpeed Thanks , That's what I thought , but one of your vids does say , that it must be tuned after install .

[@GrimmSpeed]

@crashboy40 Hey I hope we didn't give you that impression, you do NOT need a tune to install this. You do need a tune for some of our other products but this one does not require a tune to work! Let us know if you need anything at all!!

[@matthomes9486]

Our AOS is for turbo ej20/ej25 motors only. We did some testing on the N/A applications and the unit wasn't working as well as we hoped. -Matt Homes

[@whiteshark27]

@GrimmSpeed Thanks! I've been wondering what my electronics needed with PCV pressure!

[@GrimmSpeed]

@luvtomoko You actually unscrew the center core from the aos and the entire outer portion stays so you do not need to fuss with the lines or removing anything!

[@crashboy40]

Want to apollogize , it was your boost solenoid. I must have gone through all your vids quickly , and though is was about the a/s separator . Thanks for all the quick replies .

[@AntonioNguyenUS]

For the 2016 Sti its the same right? Top hose: T fitting with PCV Middle: Turbo inlet Bottom: T hose the connects to both heads

[@GrimmSpeed]

Our AOS is only intended to work with turbo applications only. We do not have a N/A versions at this time. -Matt Homes

[@anguyen5562]

Is the port closest to the front of the car connected to the turbo inlet?

[@e85junkie]

Well, I guess since the motor is going to be hot the water would evaporate eventually as where catch cans aren't heated... I just had to ask

[@GrimmSpeed]

@whiteshark27 Our AOS retains full functionality of the PCV system, the "check sensor" is not actually a sensor in the conventional way, its simply a connection to verify that the PCV system is installed. Will

[@thomaswahahauw560]

Oke what’s the difference between this type of AOS or one like IAG’s ??

[@cursedwolf23]

I know this is an old video but do I need to tune for adding this on 😅😅😅

[@BillyG869]

What happens to the PCV Valve and Operations?

[@dakotastewart3468]

Recently got a subi and the guy said I need to install this and he had it, it’s not tight like that though. I haven’t installed it yet or touched it and the center piece just slides out like nothing😭 is this a problem??

[@matthomes9486]

Isaiah, No this will not cause a CEL as long as you follow our installations instructions. Let us know if you have any other questions or concerns. -Matt Homes

[@Jayeeyee]

I still get a thin oil film/residue inside my TMIC. Also.. in colder weather.. when you shut off your car after it warms up.. the air inside the AOS lines condensate into water vapor/droplets which gets mixed up into the oil. =(

[@AMRsti93]

i ordered a red AOS thinking that the Hoses would be red as well :/ they were black :(

[@GrimmSpeedSales]

Hello, The install should be the same. All hoses and fitting should be connected to something. If you're AOS is not installed properly i would bring it back to the shop and insure they install it correctly. An improper install can lead to major engine issues.

[@GrimmSpeed]

Yup the product will work just fine with your Legacy. The part number you want to look for is our GrimmSpeed part #078016. Let me know if you have any further questions about the product or installation of it. If you do a quick search for GrimmSpeed AOS you will see another installation video for 08+ WRX and Legacy fitment. -Matt Homes

[@romeovicentini6643]

GrimmSpeed hi it will work on a 2004 xt forester ej255? Cheers

[@matthomes9486]

Our AOS is only for turbo vehicles. We tried our AOS on naturally aspirated applications, but we ere not happy with the results and discontinued N/A fitment. -Matt Homes

[@jaysoncrider5431]

Why is there a disclaimer that all products are for offroad use only when this is a product for better efficiency?

[@GrimmSpeed]

The rules and regulations vary so differently from state to state and it's very difficult to adhere to every single one of them, especially when you have a large offering of products. "For Offroad Use Only" is a statement you'll see on most aftermarket parts websites to help avoid regulatory issues.

[@85nscarola]

Will this work on 08 legacy gt? Does it have legacy specific instructions?

[@e85junkie]

So, it might be a dumb question but in past experience water is found in catch cans. Wouldn't this be allowing the water that is found in the intake system to drip into your motor????

[@phrosda]

So why would this be for off-road use only? Is a preventative maintainance thing not a performance thing.

[@GrimmSpeedSales]

We have not yet confirmed fitment on the newer Legacy but our engineers will look into this!

[@DaneGMU89]

I have the same question. I live in Alberta Canada and I get lots of cold!

[@wiseguyproductions683]

Hi can you show install on 2002 runnng front mount. I won't have those pipes on the front of the intercooler

[@INFAMOUSxCRAB]

Hi, i have bought this for a 99 wrx gc8, im assuming it is possible to set it up to work correctly?

[@TTarlov]

The difference is that GS unit is much more compact and requires less maintenance. Installing process is less involved as well. If you have milky oil on short drives then an AOS wont help you. You got bigger problems to worry about. AOS helps with blow by build up in the intake and intercooler piping.

[@crashboy40]

Hello , just saw this , and it looks good , but I also saw that you must have your engine protuned after this install . If I have a cob ap , can i use this to tune it ? Thanks

[@luvtomoko]

To pour oil from the feeler, how does it work? That entire piece have to come off to pour oil? Or will just the cap come off and AOS will stay on the feeler?

[@whiteshark27]

How come all the installs of AOS and catch cans terminate the electronic check valve on the PCV? Is there anyway to achieve air oil separation but maintain that functionality?

[@briggs9187]

300 bux is a bit much... though an oil catch can does require maintenance, it can be done with every oil change and the GS Oil air separator has to be removed with every oil change... your prices have to come down.

[@ks_ethaydius6975]

Thanks guys just ordered one for my 03 Impreza WRX. I'll be back to review when it comes in

[@justingrimm8118]

They are in the same general location but may look slightly different than in this video. We have a PDF installation guide on our website that has detailed pictures of other year vehicles. Find the product on our website and then under the product description there will be a "installation tab". Under this tab you will find a link to the PDF installation document I am speaking of. As always, if you have any further questions just give us a call @ 612.379.0000. -Matt Homes

[@thundergrundle89]

Will this work with a 2005 Legacy GT? I've read some decent reviews on you guys and was thinking about buying this for my car.

[@888red]

Do you have one for 1999 Forester turbo?

[@ts-vu3dd]

How much was this when this video came out?

[@Ken327]

@GrimmSpeed Hey Will, so will this "Check Sensor" If plugged up like you did in this video, cause a CEL by chance?

[@GrimmSpeed]

@crashboy40 Really, which video and where?

[@viperv26]

Do you need to pull the negative lead off the battery to let the ecu figure things out, or is it just PNP?

[@weathermon]

Hi guys, will this work on my 99 version 6 sti?

[@Slvr2k]

Whats the difference in this unit compared to the Crawford AOS, does this one help with short drive, auto x , and the milky oil from cold climates?

[@BigZman95]

How messy is it to remove this or work around it if you need to get to things behind it?

[@Absolute4358]

Hi , Is this the same for fitting on a 2010 model , I have the kit installed already by tuner but they've really messed it up and the right hand side pipe doesn't go anywhere , Thanks

[@jordanp6420]

Hi, really good video, so this will keep oil out of my turbo, intercooler and other intake components? Also, Subaru’s are sensitive to needing re tunes, is that the case after installing this?

[@solow970]

my first gen is a turbo. but my pvc set up is different

[@GrimmSpeed]

@myfuneral86 Yeah we actually make a kit specifically for the 08+

[@4rct1c9Ic3m4n]

I'm trying to install this on my WRX MY06. Is the hose connecting to PCB and crankcase breather port (as shown here) in the same location as in my car or is it located somewhere else?

[@MidWesti]

wish you would share the other kind of "Hoes" ; ) debating between this or the catch can for my 2011 STi... anyone have any suggestions? thnx. looks like a more simple option than the can.. install and all

[@hawkeyestiguy]

MidWeSTi I've been using this AOS on my 06 STi for about 3 years now & it works well in my opinion & I'm happy with it. The only thing that kind of annoys me about the setup, is that you need to use a ratchet anytime you want to add oil, but it's not a huge deal for me.

[@MidWesti]

HawkeyeSTiGuy thanks. seems like it wouldnt be too bad since i dont add oil unless im changing the oil out. so not often lol

[@hawkeyestiguy]

Yeah, pretty much how I feel about it. If I ever do change to a different setup, it would be more so just to try something new, & not because of a design flaw. I think it's a great product, especially for a daily driver.

[@MidWesti]

HawkeyeSTiGuy cool.. i may get this one.. thnx for the info

[@tschaderdstrom2145]

I'm sure you've long since made a decision, but the best possible option is to get a catch can. AOS is a good alternative and is much better than nothing, but simply removing the crap blowby oil from the system is always going to be the best option.

[@ethosflux]

Think this would work with a APS FMIC DR525?

[@xxftwismymottoxx]

badass product. way better than a catch can. now all u need to do is lower the price

[@zmanoside]

To think that the shop is going to try and charge me for 4 hours of labor to do this is infuriating. I should have just done the shit myself

[@EJL2004]

for this model? I had 4 hours for my IAG AOS which plumbs into the coolant lines and is a lot more invasive.

[@geturblanks]

will this make a difference or be able to install on a N/A subaru ej25 motor?

[@EdaP79]

Q? I put this on 08sti, and cleaned pcv very well was rattling around no doubt. still getting tons of oil in tmic/intake/turbo inlet/bov sprays it. double/tripple checked all hoses. nothing leaking??? hoses connected properly via instructions from grimmspeed website. Please help suggestions welcome by anyone with a decent knowledge base on this please. Thanks Edap79

[@TimFleisher]

I installed this last week on my stage 3 2003 wrx. i have a tomei turbo inlet hose and when i put this AOS on and used the cap over the metal fitting attached to the inlet. I ran some pulls afterwards for logging purposes and noticed that after the first pull my boost started leaking. I pulled over and the entire metal fitting had popped of (i guess it was launched?) Is this normal?

[@GrimmSpeed]

Actually its pretty straight forward. When you install a FMIC you either keep the metal crossover tubes or you t the lines together, either way you are still creating the same "system". A FMIC with a T is usually both heads T'd together then routing back to the inlet. Instead of routing back to the inlet route that hose to the right port on the AOS. Any more questions feel free to drop us a line @ 612.379.0000

[@cazaresvictor012]

Hi grimspeed I wanna buy this product but I read alot of reviews thats it doesn't works as well as it is claimed is that true for most vehicles? Thanks

[@ChirsSmedely]

Just installed one on mine and I’m sad to say I went through 1L of oil in 1000km (600ish miles). I like grimmspeed but I’m not overly impressed with this one. Wondering if I can add some kind of baffle on the suction side to help stop some of the oil because right now it’s basically just a drinking straw to the oil pan

[@adamroutley]

I often wonder when I see this install, wouldn't it make for a cleaner install to remove the rails to the front of the intercooler?

[@lilwrx5345]

I know this video is old, but I jumped on an old 02 wrx awhile back and I'm wondering if this AOS will fix this film of oil I have building on top of my y-pipe? Or if it's normal. Thanks for an easy install I'd appreciate some help.

[@joshr8680]

Lil WRX normal but a AOS would help, Crawford or iag are better brands. This one does not perform

[@solow970]

would it be possible to have this work on a first gen legacy ?

[@sganet_]

Can you guys make one for 2010+ Legacy GT?

[@GrimmSpeed]

@Ken327 Negative, if you do it like the instructions you have nothing to worry about!! Will

[@myfuneral86]

will this fit on 08+

[@georgedepaz5054]

What is it for

[@WheresMyAnnies]

Do you make a model that would fit an '09 2.5i?

[@Set_your_handle77]

Is the unit not Type III anodized?

[@GrimmSpeed]

Our AOS is anodized but I'll have to ask the engineers if its type III anodized...

[@that_blobeye_sti]

How tf do you fill your oil

[@GrimmSpeed]

The center section of the AOS screws off and pops out just like your oil cap.

[@that_blobeye_sti]

@@GrimmSpeed oh bet cool

[@bhayakawa16]

Will I need to replace the pcv after this mod? I just did it so how often should I? What sensor is being covered off ? Why?

[@amcheung10]

+Davileet T What about crawford performance

[@amcheung10]

Oh i was just saying if crawford was good as well

[@pronra556]

1:19 here at GrimmSpeed we have lots of hose so we decided to share it lol sorry I just had to.

[@myfuneral86]

installed it 2months ago, but removed it today.

[@xWheatThinz]

Why?

[@Constipatedoverlord]

Where do you ziptie them

[@atlanticimports6939]

+CONSTIPATED OVERLORD Obviously where the hose clamp normally would be... duh.

[@tehrockk]

very nice video!

[@isaiahmendoza5227]

will this cause a CEL?

[@kingmarz3635]

What a mess that made of the engine bay. Pointless if it's recycling hot air back through the turbo

[@stubaru]

troll says troll things.. weird

[@mediaisthevirus]

he caped off the sensor that feeds back into the inlet

[@stubaru]

your suppose to

[@Magicseven2001]

Good idea.

[@AMRsti93]

how the fuck do i undo it to add oil haha wrench?

[@husky701rider9]

Sorry Grimmspeed. But I think this is your only bad product. I absolutely love you guys and have every single part you guys make for my car. Everything from shrouds to the downpipe. I’m a dedicated fan of your products but this particular one pains me. It’s been 8 years since this video went up and many people I personally know have installed them with clear lines to see their actual performance and still get a lot of oil blow by compared to an iag or Crawford aos which plums coolant through it to keep it hot and do a better job of actually separating the oil. I understand this product was designed to be easier for people to install but it really doesn’t preform compared to other setups. I’ve tested things that vent to atmosphere as well as recirculating systems almost all have done better than this. Also if you ever wanna use my bugeye as marketing let me know. It literally has every grimspeed part you make for it minus the aos. Down to the shift knob.

[@iam_herald8084]

Will this be good for 2020 STI?

[@SkyBleedsBlood]

What does this application actually do? I own a 2004 WRX

[@meep6188]

David F are what?

[@okthen8445]

When your on high boost your sometimes suck up some oil from the turbo. That can get in your intercooler creating blow by. Enough oil and it can get in areas of your motor where it shouldn’t be like in your piston heads and creat detonation. Then good by motor.

[@BJ-uncensored]

Dailyed STi, oil in the air also decreases octane.