Yeah, I get that.
The actual big concern is catastrophic failure when you can't remove it before it's hauled to a shop.

 

I'd rather not have that going back through my intake. And from what I can tell, there is literally no harm in having one.

 

My supercharged mustang...yes, my f-150 no.

 

No opinions here from me just facts that I've purchased and run one on my truck.

 

2016 F150 3.5L here. The way I see it there are millions of these out on the road without a catch can. I don't want stuff freezing in the can during the winter months either.

 

Is there any concrete evidence they hurt anything?

 

You have hit on the gimmick! People see the condensed (liquid) combustion by-products in the bottom of the catch can, and think that goes into the intake. Without the catch can, there is no condensation and only combustion by-product vapors (gas) go back into the intake in very low concentrations. This is why they are a gimmick. Water vapor cleans valves, and combustion chambers, and condensing water vapor may have an adverse effect. Since there has been no long term testing using a catch can, like the long term testing (millions and millions of cars, running millions, and millions of miles WITHOUT a catch can, who knows?

 

id venture to say that manufacturers don’t put them on there for a few reasons. One, the vehicle is designed to get past the basic warranty stage with as little cost to the manufactures as possible. I’m not an engineer but the long term effects of an engine consuming the byproduct of a PCV system won’t be damaging at 36k or even 50k miles. Secondly, people don’t change their oil now with lights and reminders...if they don’t drain their catch cans, it can actually push more fluid in higher volume when full causing bigger issues.

GM redesigned the PCV system of the corvette to see rate the oil from the air (air oil separator aka catch can), push the clean air back into the intake and push the liquid back into the lubricating system. It literally looks like a fancy catch can you don’t have to drain.

lastly, on a personal note, I raced cars from the time I was a kid until I was old enough for the military. My whole family raced everything from late models, to sprint cars, to legends, and some still work at NASCAR tracks. Every single one of our high dollar engines had giant catch cans on them that produced quite a bit of crap. Not saying things haven’t evolved, but I know epa laws are why we don’t vent it back out into the air anymore.

i can get on board for it not being a necessity, but o can’t agree with it being a gimmick or not good for the engine to be digesting that stuff. My PCV line was coated in oil.

 

and I kinda see your point I think. By removing the 12 inch? PCV line and replacing it with 2-3 feet of hose and a metal can, are we creating an environment that will produce more vapor and more condensation this giving the appearance of the catch can saving us? I don’t know. All I know is that my PCV line was dripping black liquid that smelled like oil...that means on a stock truck, that black liquid was getting ready to be dumped in my intake...no thanks.

 

If a catch can didn't have some benefit, why did Ford come out with their own?