Audi RS5 B8 Oil catch can

Hi guys.

Over the weekend I bought some CRC cleaner and I am just waiting for that to arrive so I could have a little go in helping to minimize the carbon build up like what ape factory did that video was really helpful btw!.

Was just doing abit of research as well about having an oil catch can to help with the prevention of the carbon build up these 4.2 V8 FSI engines are known for.

Was just wondering has any of the members fitted one and if possible be able to guide me on how to fit one in what equipment and materials do I need? As I can’t find anyone who has fitted one online. Can only find like the Audi S5 4.2V8 but then the pcv intake system is a different layout to the RS5, and the RS5 doesn’t have as much room either so where would be the best place to place one?

Be much appreciated for your help.


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I’m working on designing one actually but here’s the thing…the carbon buildup comes not only from volatiles in the intake path (via the PCV) but also through oil leakage on the valve guides in the head and valve overlap when there’s a bit of blowback from the combustion cycle. Even though the intake valves would be seriously hot to the touch, they’re far cooler than the combustion gasses so they accumulate quite readily on the much colder (relatively!) valves.

But…If you can remove more volatiles from the intake tract, has to help a bit. It won’t eliminate carbon buildup though.

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Yes, the PCV valve design on the RS5 is very different from that on the S5 and it seems that with properly working PCV valves should suck most of it past the valves and into the combustion chambers.

For that reason, I am not sure I would personally put a catch can as the proper flow of the air liquid mixture will help cool the intake a bit and ensure the carbon is blown past: at least in as far as the catch can, depending on design, will trap the liquid which would both help clean and also as mentioned cool the mixture as it turns into steam.

On mine there has been no sign of leaks from the valve seals as there was oily carbon on the walls – the tough shiny/metallic build up almost on the valve heads exclusively. I will personally try to see if using CRC valve clean or similar products will have a preventative effect on the build up (will pull the intake about once a year/10.000 miles and apply the product directly).

If it does not get worse I can live with the slight build up on the heads as long as there is no restrictions before in the air flow it should possible to limit it.

Once again I’d be interested in your finished catch can design !! Keep me up to date on how you get on with this and i know you being you will try and test it very thoroughly before your happy to commit on the finished product and that’s good enough for me !! :+1:

I just secured a source for the OEM fittings earlier in the week. Last thing I need to do is figure out an adapter to go from the new hoses to the PCV hoses using that OEM fitting. Otherwise it’d mean cutting those hoses off altogether and connecting directly to the PCV fitting. I could offer both options as those hoses do crack with time and cause issues.

I’ll also be relaunching the air pump hose relocation kit with OEM fittings. I still have to figure out the final spec but it may actually come in less expensive than the original version which used two very hard to get and rare components.

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Sounds like your on it ! Keep us posted on how things are going and when its ready for release, I’m interested in this anything to keep the carbon build up away or even to slow it down will be beneficial.

I put mine behind the motor

Had to remove the blue balls from behind there but that’s about it had to make block off plates for the intake also

That’s a very nice setup running a twin can. Since I last posted I have installed my catch can setup but it is only a single can.

I have seen some other members on Facebook they have fitted twin cans underneath the scuttle panel but I did not want the hassle of always removing the scuttle to check on the oil collection levels.

But anyways here is my setup with a custom mount bracket.

Oh wow… You crazy son of a b*TCH you fit one in there!!! I was trying to figure out how to run it there and nice setup with the hoses

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looking great,
I really like the way you set up this catch can,
would you be able to make apart list or even sell me similar kit ?

thanks :slight_smile:

Do you got more photos of this setup? What are the lines under the intake

I’m also confused with lines connected to intake elbow underneath, where is it coming from and what to do with it :thinking:

Happy new year everyone,

just to follow up on CATCH CAN any updates ?


Not yet we are still waiting Ape is on the case tho !

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Hello Ray,

Just copied your design for catch can, used 20mm ID silicon hoses and plastic fittings 90 elbow and T
wanted to ask you what fittings you used, I’m worried the plastic ones I’m using might melt down or deform from heat ?

also the special mount for the can it self, could you elaborate more on that or share a photo or design ?

thanks :slight_smile:

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@a_ibrahem Hi buddy.

Apologies for the late reply! Awesome work you done there buddy! Should be really proud of your work! I too have used plastic fittings 90 elbows and T bends. I more than fit for purpose for the job, so no need to worry there. But if you are worried I believe you can get those 19mm I.D fittings in brass.

With the mount for the catch can it was just abit of straight aluminium plate about 30-35mm wide and 4mm thick that I painted black to make it look more OEM. I then M6 threaded the plate so that the two bolts would screw on it plate in to position and even added nuts underneath to make it more secure to the frame of the car.

With the bolts for the catch can I just drill two holes through the plate and use the fixing bolts supplied with the kit to attach the can. Hope this helps.

From the first image I have posted I have made some alterations with the pipe work fittings will get a picture up asap for you to see

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Hi Ray,

Thanks lot for reply, appreciate good word :blush:

Believe will be do something similar to mount the can

What hoses are you using ?,looks more slim and flexible than my silicon 20mm ID than I’m using

Waiting for the new pipe work photo :heart_eyes:

Hi @Ray_86,
here is my attempt to do similar mount, definitely your looks better, but its holding strong and does the job :slight_smile:

don’t forget pic for new pipe work @Ray_86 please :slight_smile:

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Trying to do a catch can setup for an s6, where did you find your connectors to the valve covers?