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Discussion Starter · #1 ·
Hey guys

So I've always had a bit of oil leaking out the PCV system into the air filter, but not enough to warrant making a project out of it. The intake of my YJ was replaced by the previous owner and upgraded to a Power Adder intake, which is very similar to most K&N performance intakes, without the enclosure.

Now because there is no enclosure, the platform the stock air box mounted on was left open. I installed a $30 Fiamm air horn kit where it used to be, but part of the tubing was melted apart by a mysterious heat source. Now, I used to have the same air horns mounted on opposite side of the engine bay, but only failed to work when water rusted the horns themselves out (see: mount with bells facing down...). So I believe the culprit to be hot oil coming from the crankcase. In order to remedy this, I decided to make an oil catcher. I have seen them advertised online, but the only ones I could find were very expensive.

From what I have read, oil leaking out of the valve cover, through the PCV hoses and into your air filter is caused by excessive blow-by. Blow-by is when you lose compression due to a poor seal between the piston rings and the cylinder walls.

Because new rings, or an engine rebuild is way out of my budget, I decided to create a very cheap and simple way to keep oil from reaching my air filter.

Materials:

-1 jar. Threaded is probably the easiest and secure type, but there's a world of parts out there. The jar I bought is made from some type of metal, It's not steel, probably some cheap aluminum alloy. The jar I bought is a "Monster Pill Fob", marketed by some unknown company. They have them at my hardware store along with the other doo-dads on the counter. I have been thinking about this project for a while and the monster pill fob things have seemed like the only viable, metal jar I can find. I figure this jar is about 2-3 fluid ounces and shouldn't need to be emptied that often.

2- Stainless hose clamps. The width of your PCV hoses may be different than mine, so measure and buy accordingly. I used SS because it's one less thing to rust in New England winters.

2- Barbed hose fittings. I bought a straight and a 90* fitting, but I would recomend getting fittings that work with how you want to mount your oil catcher. If it's going to be below the level of the hose, then two straight fittings will probably work best. If it's going to be floating, or on the same plane as the PCV hose, then two 90* fittings would work best. I bought a straight and a 90* because they ran out of stright fittings. While the straight fittings only cost about $2.50, the 90* fittings cost about $6, and I couldn't afford two 90* fittings. The ones I bought were 3/8" OD, with 1/4 NPT (National Pipe Thread) threads. Buy fittings that properly accommodate your PCV hoses.

All together, my total came to just over $19.00, so this is something most people can afford to make, provided you have access to a small variety of tools:

Jar- $8.00
Clamps- $1.29/piece
Straight fitting- $2.50
90* fitting- $6.00



For tools, you're going to need:
-Tap, appropriate for thread pitch of fittings
-Tap handle (I used a pair of Vice Grips)
-Drill bit, appropriate for size of tap
-Center punch (I used a small tap)
-Cutting oil (for cutting threads)
-Screwdriver (for hose clamps)
-Hacksaw
-File
-Drill press or power drill
-Bench vice

Most of these tools are household items. A tap usually costs between $5-$10, and the drill bit is about the same due to it's large size.



The first thing I did was to remove the small nub from the top. I used some masking tape around the top to protect the finish. I recommend using stronger tape like electrical or duct, as my saw scraped away some of the tape and marred the finish:



After that, mark, punch, drill, and tap the first hole:



Now keep in mind, these are plumbing fittings that are threaded for NPT (National Pipe Thread), which taper out as you continue to cut the threads. In other words, the more of the tap you use, the wide the hole is going to get. So, every couple turns as you're cutting your threads, remove the tap and see how your fittings fit. Once they feel snug around the top of the threads, that's as far as you need to cut.

Both holes, drilled and tapped:



I have to say, the metal that the jar was made out of was very thin. If you use a similar type jar, be careful to start the threads straight because you could widen the hole past the point of threading.

Here is the lid with both fittings installed:



The underside of the lid, with the barb fittings installed:



And the complete project:



I sealed the threads with blue loctite, however I'm sure Teflon tape or nail polish will work fine as well.

After it's finished, you just need to cut the hose and clamp them to the fittings once you're jar is installed in your Jeep.

Since I messed up the shiny finished, I decided to paint the very top of the jar, but left the bottom it's chrome/silvery finish. I'll have some pictures up as soon as I have it installed.

All together, this was a very quick, easy, and cheap project that most people are capable of and can help prevent oil from reaching your air filter.

Let me know what you guys think!

-Ringwood
 

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Discussion Starter · #2 · (Edited)
The only response I was able to evoke was from a spam ad guy, who can't even do his job right.

I fail.

:p
 

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Definitely not a fail, this is a great idea and I like how compact it is. I might want to do this to mine now, I would like to see it installed.

Rich
 

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This is an awesome write up! I never thought about just making something, I was looking to find like a old fuel bowl off an old tractor, like the glass ones. I guess it doesnt need to be glass its just gonna get oily anyway, haha. I'll have to keep my eye out for a jar like that!
 

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Discussion Starter · #5 ·
I originally thought to use a glass jar, as I don't know where aluminum jars and other type containers would be sold, but I was afraid it would break under the hood and just cause an oils, painful mess.

I am going to see how it does just floating on the hose. It's a very heavy duty hose, probably 1 1/4" OD, but only 3/8" ID. Afterwards I would work on making some kind of holder or clamping system like on a fire extinguisher.
 

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Not bad. My blowby has slowed down since I bought the YJ over a year ago. The PO must have never done maintenance because she was spewing oil into the filter all the time.

If it ever gets that bad again I'll do something similar to protect my air filter.
 

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Nice Mod!..just in time too because I've been thinking of a way to eliminate the oil going into the intake tube on mine also..thanks
 

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I assume the vapors come out thru the second pipe and the oil stays inside, correct?

I would be afraid to induce high pressures on the crankcase and blow my seals
 

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I assume the vapors come out thru the second pipe and the oil stays inside, correct?

I would be afraid to induce high pressures on the crankcase and blow my seals
It still has the same flow and breathing quality/rate as the stock setup,only the flow goes through the can and collects the oil instead of blowing into the intake/engine.

Ive used this type of mod on a few vehicles and never had a problem blowing seals,but instead of using a catch can i just used a hose and mounted it above the engine and put a breather on it and you could smell oil all the time inside the vehicles,this prevents that since it is going back into the system
 

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I'd just like to point out that if you guys would properly service your CCV systems 98.467% of these extreme blowby cases would instantly disappear along with the need for these Rube Goldberg fixes.

My junk used to puke all kinds if oily junk atop my filter. But after cleaning out the vacuum tube and valve cover baffles a filter will now last me years and only get a slight oil skidmark in the process.


Besides if it's an issue even after servicing the CCV you can always install a road draft tube which is what I did till I had time to pull my valve cover
 

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IIRC, years ago, before I rebuilt my motor, I had some bad blowby, and rigged up the following system:

Take a quart plastic oil jug. Remove the line from the rear of the valve cover, and use a 90-degree plastic elbow, run a hose down to under the master cylinder into the gap behind the front driver side wheel.

Put a Tee sidways into the top of the plastic oil jug. Use the jug as a catch can, Put a breather on the top part of the tee, and connect the hose to the horizontal part of the Tee. Just make sure the hose from the valve cover is always going downhill to the plastic jug. Put the jug in the gap in front of the firewall and prop it up somehow.

Worked great.

Pete
 

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Check out post 87 on page 6 in the Made a ___ sticky. Pictures, step by step instructions, list of materials. Kinda cool I think!!:thumbsup:
 

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I used a Kerosene fuel filter I picked up at a local hardware store I used to work for. Just take out the filter media and replace it with either a stainless steel scrubber pad used for cleaning pots and pans for extra efficency. If you really want to do it right put a copper cleaning pad in there. It works great.
 
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