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Oil Catch Can vs. Breather

66K views 211 replies 42 participants last post by  bodon 
#1 ·
Who can help me out here? I've never had experience with either. Which one do you all recommend? How do they both work? Any info would be great
 
#2 ·
Breathers are the only way to go. Just make sure you remove the check valve ( little metal ball and a small pin) on the passenger side pcv fitting coming out of the coil cover.

The catch cans suck. They still let oil into the intake.

And no the breathers do not let oil onto your valve covers

Sent from my HTC One using Mustang Evolution mobile app
 
#13 · (Edited)
#14 · (Edited)
Finally got off my ass and did it this afternoon. I trimmed down the passenger side PCV about 1.5cm so it didn't stick up, and also removed the checkvalve inside it.

Quick note, normal vacuum caps won't cover the holes left in the intake and the engine side of the pcv hose. They are about 1/2", and the 'advance o'reilly zones' around my area didn't carry vacuum caps that were any bigger than 3/8". I had to get a cap meant for the cooling system to fit. Looks great, fits perfectly.

Might eventually paint the passenger side PCV valve to something other than bright blue at some point. Just me being OCD I guess.

----edit----
The breathers I used were the el cheapo ones at O'reillys. Spectre, part number 3991. Watch your fingers when drilling out the bung to 1/2", I about made a nice hole in my dumb hand today.
 
#16 ·
Aye, they weren't with the normal vacuum caps. Had to go over near the area with the cooling system hoses and fluids to find what I needed.
 
#22 ·
You only need one catch can or breather filter, and that's on the passenger side. The drivers side is where the engine draws air into the crankcase, so that side drawing air from the stock tube via the air intake to the engine cover is fine. Adding one for looks or "balance" works though.

The passenger side is the culprit for the oil mist, so either a catch can (you can make your own using the existing tube and plum in your own can) or the breather works. The breather will need to be cleaned, and yes, it will eventually dump oil onto the passenger side engine cover if you don't clean it. With around 650 highway miles I frive a month, I see around 4 tablespoons of oil; that's alot for a breather filter to be expected to hold without periodic cleaning. Breathers are certainly the cheaper way to do it, just be sure to inspect them.
 
#33 · (Edited)
Examine the crankcase ventilation setup. On the drivers side, theres a tube that runs from near the air cleaner box (stock) or CAI tube to the drivers side head cover. This is the engines crankcase intake. On the right side (passenger), the crankcase gases/oil mist is drawn out via the PCV valve, through a tube that connects to the intake.

It is on this side that the oil vapor is going to exist, nothing on the drivers side.

Since air is drawn in from the drivers side via the tube that runs near the air filter box to the head cover, you don't need a breather on that side, but by installing one, it makes the engine bay look nice and balanced with the one thats required on the passenger side.

Either a breather or a can works. Your choice.
 
#34 ·
#38 ·
Someone have an install write-up? Just picked up a couple from the auto parts store for $20

Sent from church, because I'm out of cheerios.
 
#39 · (Edited)
#40 ·
I need a bit more help than that, lol. Block off caps? Size? Quantity? Where can I find them?
 
#41 · (Edited)
Gotcha. I posted the links as I figured they might have the blockoff caps sold perhaps seperately, or maybe listed in the link as to their size. Or, it would give you some ideas on a search.

Here's what I found: You'll need 1/2 inch caps to fit over the 1/2 inch nipples when the stock tubes are removed. Here's one link to a site that sells them (6 bucks for 10; can most likely find them at an auto parts store):

10 Rubber Vacuum Caps Black for 1 2" Diameter | eBay
 
#42 ·
The block off caps are 1/2" rubber vacuum caps. Problem is, I couldn't find a pack of caps at my local parts stores that would fit so I found a cooling line cap kit that had a 1/2" fitting. Essentially the same thing, a little black cap with a half inch opening. You'll need two; one that fits on the underside of your throttle body and another that fits on the port on the intake. Simple stuff, don't overthink it!

The filters I used were the ones you find at any parts store - spectre breather filters part number 3991 (black) or 3992 (red). Take a 1/2" drill bit and widen the hole in the rubber so it will fit. Make sure to get all the rubber fragments out of the filter before installing it - duh. Hose clamp them on.
If you think your passenger side sticks up too far (the blue one, you'll see what I mean), trim it down about half an inch. While you're at it, take out the blue PCV valve altogether and pull the black ring off the bottom end of it and pull out the checkvalve that is inside it (sorta pointless to run a breather filter with the check valve in place).

Autozone, O'reilly's, Advance Auto, Pepboys outta have everything you'll need - except maybe a good sharp knife to trim down the passenger side pcv valve.
 
#43 ·
Awesome, very helpful thank you. Although telling someone trying to learn to do their own mods, rather than pay a shop an outrageous amount, on their $35k vehicle "don't overthink it" is a little moot lol.
 
#47 ·
2 per side? I plan on doing both.

Sent from church, because I'm out of cheerios.
 
#50 ·
Hey guys quick question. I'm looking into getting a breather kit set up for mine and checked out JPC racing and it looks like they use a K&N set up. I'm wondering if anyone knows if these ones on Amazon ( K&N 62-1495 Vent Filters) are the same ones JPC is using. I'm getting my valve covers off to powder coat and replace the gasket this weekend and think amazon may be able to get me these breathers faster than JPC.
 
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