I just installed an oil catch can on my car. I was wondering, How often are you supposed to drain it? And Is it supposed to be just oil that drains out of it? Cause i drained mine and there appoeard to be a little water in it.

 

thats just normal moister build up ... check your oil and dipstick just to make sure there not milky to be on the safe side but there realy aint nuttin to worry about ... unless lol when u change your oil and ther water in it of course

 

My catch can collects a milky oily substance in it. if that helps you any. I drain it every few passes or so. The larger the catch can line is, ie. -10 or -12, the less oil you get in your can...

 

Ok. Thanks!

 

I don't know a lot about catch cans, but why does the -10 or -12 allow less oil into your can?