There is a lot of discussion regarding catch cans and dirty intake valves.... I also have read where the Skyactiv G has an oil separator on the engine.. Does the separator do the same as the catch can? As I understand it, the oil separator separates the oils and fluids from the air in the PCV and the fluids would go back into the crank case. The catch can stores fluids and the can has to be emptied.

So, and advice and comments would be appreciated.

 

I want to first state that I am not saying not to get one, but if you do try to spend a little more and get a good quality catch can and you may still need to modify it to work somewhat efferently enough for what they are?

Catch cans can do some slight positive reduction in oil going through the intake but not as good as the retailer and manufactures claim they do. Naturally if your engine already has some health issues and blow by is an concern (confirm with leak down test) you will always see more oil collected in any catch can.
Because in my testing when deciding on to introduce my own engineered CATCH CAN system I found no one marketed that really worked on Carbureted, or boosted engines like Super Charged or Turbo charged engines.
I do run one on the breather side and will likely do a 2 can system on the PCV side to reduce the oil vapors. But my method to completely keep the intake and combustion area's clean is with a water injection system . As of my last oil change the only thing I collected in the breather catch can is "air" lol


I have never read any technical article that claims the MAZDA Ski Activ engine returns accumulated oil from the intake through the PCV system to to return it back into the sump! But if there is one I would appreciate the link!

Somewhere (??) on my thread I show a modified and installed catch can breather side for my MAZDA.
https://www.mazdaforum.com/forum/maz...like-do-44018/

 

Thank you very much for your reply. I will get the link where I saw the separator on a Mazda motor. This was from a Mazda manual also.....

 

Mazda CX-5 Service & Repair Manual - Positive Crankcase Ventilation (PCV) Valve Removal/Installation - Emissions

Go to this link and you can see where Mazda references an oil separator..... Let me know what you thihk.

 

I know this picture but it is not a write up on how MAZDA solved the physics of oil vapor contamination in the combustion chambers nor is it really suggesting anything, it is a name of a part but the name does implies things doesn't it? lol A simple canister they call an oil separator yet no real information as to it function other then the name? Again if we understand basic fluid dynamics and specifically how motor oil in a vaporized state works some of us would sorta go hmmmm to most catch can use advantages in the first place. I give the reference to location that most catch can manufactures suggest in their installation instructions. To have a device as an oil vapor catch can work to some degree you need to first locate it as low as possible at or below the short block pan mounting surface and also where it will be quickly cool by some form of air flow . This is where I get into trouble because I do test theories and idea's and sadly what we all think is a solution because of a name is not really.

Once again I am not saying not to use one because all things that are design so do positive will have an effect on the whole but not to suggest that anyone weigh there idea's that a catch can is a cure all to a problem that has not been resolved with the engineering design of a GDI engine. (Gasoline direct injection)

 

Thank you for your replay.. At this time I will not install a catch can on my CX 5. One has to remove the intake manifold in order to get to the PCV which souinds like a lot of work. My car only has 7,000 miles on it...