Valve Cover Breathers

[linguinipenguini]

Can valve cover breather filters harm your engine? What are the benefits/disadvantages of them?

[timot_one]

I wouldn't use one.  Your valve cover has a breather line that goes to your intake to create a vacuum.  The smart thing to do is to get an air oil separator/catch can for that line from your valve cover to your intake.  That will keep your intake tract from oily deposits.

[Rushzer0]

^He speaks the truth I spent about an hour reading about this exact topic on k20a.org last night, putting on a breather filter will only give moisture a possible way to enter the lubricating system and contaminate your oil, making it froth and such.

[CrackerTeg]

Translation: no bueno.

[timot_one]

Sometimes I know what I'm talking about.  When it comes to being a daily driver, you're better off with an air oil separator over the breather filter.

[linguinipenguini]

Ah. I just installed a new intake and im having trouble with the vacuum hose that goes to the valve cover.my thought process was to put on a breather and seal off the connection on the intake pipe. If i did an oil change every 3-4K miles would this reduce the risk? Also, there is a 90 degree elbow that connected the old valve cover line to the intake. It also has two coolant lines attached to it. Is it okay to delete this elbow and directly connect the coolant to its port? I'm sorry i have no pictures, but if you know what im talking about  please reply!

[timot_one]

You can delete the coolant elbow.  I would not recommend that you use the breather filter on the valve cover though.  Again, there is supposed to be a vacuum from the intake on the valve cover.  It's really something that you should continue to use.  But go ahead and do whatever you like.

[linguinipenguini]

I deleted the coolant elbow, but stuck with a vacuum line for the valve cover

[si2accord]

I have them on my car with no problem 

[timot_one]

Since this thread was last posted in, I've actually made some changes on my motor set up. I have 2 additional -10 an ports on my valve cover and have the OEM breather and PCV deleted and all of these going to a vented catch can.

I doubt you'll see much benefit either way on a stock set up, but on a boosted or built motor it's better to have them vent to atmosphere with a catch can.