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Product Media
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
Community Media
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+
User Media for: GrimmSpeed Air Oil Separator - Subaru WRX 2002-2007 / STI 2004+

GrimmSpeed Air Oil Separator

Subaru WRX 2002-2007 / STI 2004+

Read 39 Reviews | 15 Q&As
Part # 078006
$299.00
On Sale

In stock!
Ships today if ordered in
12 hrs 54 mins

Features & Product Details

The Grimmspeed Air-Oil Separator (AOS) is one of RallySport Direct's highly sought after items. Grimspeed uses a unique patent pending design which allows you to maintain your PCV valve while separating oil from the air in both the heads and crankcase. These boxer engines have inherent issues with harmful oil and vapors getting into the intake system of your vehicle which can cause issues like having an effect on the octane rating with your gas, and after long periods of use and mileage can cause buildup on your valves.

This particular air-oil separator takes the place of an oil catch can, or a tank which is convenient to eliminate the need to empty the catch can. This is a subtle installation that replaces your factory oil filler cap.

New lines, fittings, and zip ties will be included to make this catch can system ready for the installation. 

Note that this particular unit will come in the anodized black finish for protection against corrosion, and to add a nice touch to the theme of your engine bay. 

Product Video

Specifications

Brand: GrimmSpeed
Color: Black
Installation Hardware Included: Yes
Material: Aluminum
Mfgr. Warranty: Lifetime
Condition: New Product
Return Policy:

RallySport Guarantee - 30 Days


Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
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REVIEWS & CUSTOMER MEDIA

39 Reviews
4.6 out of 5 Stars
5 Stars
(30)
4 Stars
(4)
3 Stars
(3)
2 Stars
(2)
1 Stars
(0)
Customer Photos and Videos
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
GrimmSpeed Air Oil Separator ( Part Number: 078006)
Used this for years, now don't 3 months ago
2out of 5stars

I had this on my car and used it for years, it isn't that great at doing its job. I had to continually clean the separator as it would get bubbles in the oil and would gather foam around the top. These bubbles never made it to the oil pan, only inside the AOS. I finally got a IAG air oil separator and its way better. Would never go back.
  
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1 of 1 people found the following review helpful
Easy to install but not worth it 6 months ago
3out of 5stars

I’m currently finishin my mild build (400-500whp) and my nationally renowned tuner informed me that this part is only good for one thing ... “Having to use a wrench to put oil in your car” and instructed me to get the IAG AOS instead.
  
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1 of 1 people found the following review helpful
Works great! 1 year ago
5out of 5stars

Currently tuning my JDM EJ swap and found oil build after the intercooler and before intake manifold. For my street driven WRX, this AOS has completely removed the oil from the intake and my runner is happy since it reduced knock issues after it was installed. I plan on tracking pretty soon and plan on adding a catch can In line with the hose that runs to the intake, as a just incase. But yeah this thing is great and isn't an eye sore in the engine bay.
  
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1 of 1 people found the following review helpful
necessary upgrade.. 1 year ago
5out of 5stars

Received the item well packed, great quality, all necessary parts included, BUT I wished they included hose clamps, rather than zip ties, and NO instructions included, luckily it was easy to install, and the instructions are available online or YouTube videos is a good source. After installing this AOS on my 2005 Sti, I felt the difference after driving the car for few miles, runs great and smooth. I definitely recommend this for your daily driver. Not sure for racing yet.
  
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2 of 2 people found the following review helpful
Not perfect but it checks all the right boxes.  2 years ago
4out of 5stars

I've had this installed for 5000 miles now and I put it on after a fresh change of oil so I think I can give an accurate evaluation to its performance. This is not going to perform as flawlessly as a $500 swirl pot unit but it certainly gets the job done; this product more or less shines in the ease of installation department. I was using just over a quart every 5000 now i'm only using just enough to see it move on the dipstick before an oil change, maybe 1/4 a quart or less is being used every 5000. Would have liked to see clamps included instead of zip ties for a product at this price point and oil does seep out of the top (you can see some grime stuck to where oil has worked its way out in the photo) so it ranks mediocre in quality for those reasons. Overall would purchase this item again because the value is still there despite my complaints, It just gets the job done.
  
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QUESTIONS & ANSWERS

  • Q: Street /track  13stisedan1 year ago

    Hi I read a review from a few years ago here about the older version of this AOS not seperating properly after heavy track use causing it to smoke from the cap seal and it was stated that GS is aware and working on an update? I'm guessing because of the style of this AOS that a proper track version isn't in the works?
    • 0 of 1 people found the following answer helpful

      A:  I would recommend looking at other options if you are going to use your car on the track

      Devan M. @ RallySport Direct 1 year ago  
        
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  • Q: Fitment  dmonti117399515 years ago

    Someone is selling one of these off of a 2012 wrx, why will a 2012 STI confirm fitment but not a 2012 wrx? It is just the part that screws in and i am wondering if its just that particular part will it work?! :)
    • 0 of 0 people found the following answer helpful

      A:  The 2008-2014 WRX models have a very different setup when it comes to induction and ventilation, it may be adaptable but this is not a direct fit and purchasing the correct AOS for your vehicle is recommended for ease of install.

      Nick S. @ RallySport Direct 5 years ago  
        
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  • Q: Install video valid on 15 STI?  wongchonghing852585 years ago

    Was curious if the install video applies for the 2015 STI? All step and procedures are the same in the video for installation on 2015 STI?
    • 0 of 1 people found the following answer helpful

      A:  The install should still be the same on your car.

      guest56ad69792a8d256e198b66b5 @
        
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  • Q: Power Rating  sikknt5 years ago

    Does this still work if you're running 400hp?
    • 0 of 1 people found the following answer helpful

      A:  This will still work with no issues.

      Kyle A. @ RallySport Direct 5 years ago  
        
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    • 0 of 1 people found the following answer helpful

      A:  Horsepower shouldn't be a limiting factor as long as your engine is running healthy and has no more than factory amounts of blow by. Mike

      GrimmSpeed
        
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  • Q: does it fit a 08+ wrx or only sti?  nicatlotus633595 years ago

    Will it fit my 2013 wrx or sti only?
    • 0 of 0 people found the following answer helpful

      A:  We have a different part for the WRX http://www.rallysportdirect.com/GrimmSpeed-078016-Air-Oil-Separator Mike

      GrimmSpeed
        
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    • 0 of 0 people found the following answer helpful

      A:  Unfortunately this one is not made for those years of WRX's however, here is the Grimmspeed AOS that you would need: http://www.rallysportdirect.com/GrimmSpeed-078016-Air-Oil-Separator

      guest57853c642a8d25b5018c44a7 @
        
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