I recently finished a DIY oil catch can install. It's based on a design from <a href="http://www.aaronreedbaker.com/oil.html">here</a> which was put into a turbo Volvo. That design has a snazzy clear oil level hose I didn't include because I gave up trying to find clear hose with temperature ratings I wanted. I also didn't include a drain valve because it'd be a bear to reach where I mounted the can. Instead, I'll just periodically check it by taking the top off the can and sucking out oil with a small hose if I need to. While I had the Y-pipe out, I sanded it some and painted it with inspiration from the two write-ups I found on this forum <a href="https://forums.audiworld.com/s4/msgs/2518954.phtml">here</a> and <a href="https://forums.audiworld.com/s4/msgs/2423625.phtml">here</a>. Their's came out nicer than mine, but I frequently have to be satisfied with mediocrity when it comes to spray painting since I seem to be pretty bad at it.

I learned about catch can installs on this forum through these tech writeups and posts: <a href="https://www.audiworld.com/tech/eng91.shtml">1</a>, <a href="https://forums.audiworld.com/s4/msgs/2679936.phtml">2</a>, <a href="https://forums.audiworld.com/s4/msgs/2680006.phtml">3</a>, <a href="https://forums.audiworld.com/s4/msgs/2653657.phtml">4</a>, <a href="https://forums.audiworld.com/s4/msgs/2653487.phtml">5</a>, <a href="https://forums.audiworld.com/s4/msgs/2653473.phtml">6</a>, and <a href="https://forums.audiworld.com/s4/msgs/2653493.phtml">7</a>. Thanks to those authors for the education.

Earlier this year, with about 85K on the car, I put in the AWE ICs, along with some other upgrades, and discovered one to two tablespoons worth of oil in the driver side IC hoses and in the IC itself. I started looking at catch can installations to keep the new ICs clean, clean up the Y-pipe, and to help the engine burn cleaner internally.

Here's the bay before the OCC install. Note the bolt in the back I used to secure the OCC. I removed the bolt, drilled a hole in the middle of a large hose clamp, then mounted the clamp with the bolt.

<img src="http://pictureposter.audiworld.com/113875/1-before.jpg">

The supplies I picked up included an aluminum camping fuel bottle for the can, an updated PCV spider hose from the dealer for about $120, a couple stainless steel pot scrubbers from a restaurant supply shop, lengths of oil-resistant PCV hose to match the inner diameter of the pressure limiting valve and the hose section to the intake manifold, plus a couple brass hose barbs, an elbow, t-coupler, and a bunch of hose clamps. I certainly could have done this on the cheap with my old spider hose, but I wanted to take my time putting it together and drive the car while I was doing it, plus I figured it'd be good to start with nice clean new hoses and valves.

In the following picture, I've already removed the section of spider hose that goes to the IM and includes the check valve and capped off the output from the distributor piece. The picture also shows the spider hose barb that goes to the N75 capped, but I later decided to uncap that and hook it up normally to the N75 since the old N75 hose was pretty clean. It appears most oil doesn't precipitate out until later along in the spider hose. Apparently you can vent the N75 to the atmosphere, but I'm pretty paranoid so I hooked it back up like it's supposed to be.

<img src="http://pictureposter.audiworld.com/113875/2-supplies.jpg">

I drilled two holes in the bottle. One about midway up for the dirty side, and one near the top for the clean side. I inserted the barbs and secured them with JB Weld, then painted the bottle black with some high-temp clearcoat. I stuffed one of the stainless steel scrubbers into the bottle to act as baffle material between the two barbs. Air flows very well through the scrubbers, and hopefully all that surface area will help the oil precipitate out of the gases into the can.

<img src="http://pictureposter.audiworld.com/113875/3-bottle-painted.jpg">

Getting the old spider hose out was a pain. The rest was easy, but tedious. The lower bottle barb needed to be connected to the output of the spider hose distributor piece that would normally go to the pressure limiting valve on the Y-pipe. The bend was too sharp for the rubber PCV hose causing a kink, so I put in a brass elbow midway. Out from the top barb, the hose leads to the pressure limiting valve on the Y-pipe, with a T-connector and hose heading down to the intake manifold hose with the check valve. After I took this picture, I had to cut a little off the topmost hose segment between the bottle and the T, then had to move the rest of the hose underneath the boost gauge line to get it to line up with the barb on the pressure limiting valve.

<img src="http://pictureposter.audiworld.com/113875/4-bottle-in-place.jpg">

A little hose shortening and rearranging plus putting the painted Y-pipe back in and attaching the valve came out like this.

<img src="http://pictureposter.audiworld.com/113875/5-hooked-up.jpg">

And finally a couple of wider shots for show the finished product.

<img src="http://pictureposter.audiworld.com/113875/6-completed.jpg">

<img src="http://pictureposter.audiworld.com/113875/7-covered.jpg">

I don't know if this setup will help as well as the commercial OCCs, but it was a fun project and at least I'm pretty sure it won't hurt anything. I only have a couple hundred miles on it so far, so I anticipate it'll be a while before I see any results. Suggestions for improvement and comments are welcome.

 

Excellent post. Nicely done. Looks sharp!

 

that is good... well done.

 

good write up - it doesnt look bad at all!

 

Why not a drain like the one in the link? Nice BTW.

 

there's very little space between the bottom of the bottle and the spider hose distributor to put anything. I thought about trying to put a chuck on the side near the bottom, but then couldn't figure out where to hang a hose for access from underneath so I just said screw it and I'll suck it out when the time comes.

 

nice job! doesnt look bad at all! I plan on revising my install shortly as well.

 

<center><img src="https://www.audiworld.com/tech/pics/eng91_AMW_Can8.jpg"></center><p>you have the line going from the spyder hose going to the bottom barb of the catch can and the top barb going to the y pipe, while in the pic the line from the spyder hose goes to the top of the catch can and the side goes to the y pipe. just curious

 

I guess I put the clean side barb on the top because I figured gravity might help.

 

barb on the amw catch can was filtered so nothing gets back in there. also i know the amw can are $$$ there will be a groupbuy on supraforums soon for ones similar in quality but alot cheaper just a heads up