Hello - I recently installed oil catch can as I was seeing oil in the intake tube and I drove for 2000KM and I forgot to drain the catch can which resulted in foamy stuff in the engine oil cap and check in light with link failure of some kind in the dash. I drained the catch can and the check engine light went away. I live close to Toronto where it can get -20C during winter, I see quite a few issues popping up after the catch can installation; when it was really cold when I tried to start up, I heard noise coming from the valve spring(I think it'* valve sprint but I could be wrong), I stopped and restarted the car the noise went away.
Did I cause damage to the engine by not draining the catch can ?
I'm now not sure if installing catch can is helping or causing issues. Any advice on should I keep or remove the catch can ?

Is this catch can installed inline with the PCV system, with each hose connecting where the factory PCV hose connected on each end?

Does any part of the catch can system have valves in it?

I've never seen foam like that in a 3.6 . That'* weird. If the catch can caused it, I don't know for sure how it would have done so. Theoretically, everything in the catch can was a vapor in the crank case at one point.

Maybe since the catch can was full, crankcase vapors had nowhere else to go except out through the oil cap . . . ? A full catch can might require crankcase vapor to push oil uphill to get out.

To answer your question: If the catch can does not have any valves on it, and always allows PCV vapors to flow both directions as well as they would without the catch can, I don't think installing the catch can would break anything. Letting it get full and then over full might have caused issues.

Taking a step back, I'm going to offer my opinion: Catch cans are gimmicky in my mind. I know they have their place in some applications, but I also see folks install them on all kinds of things that otherwise have no need for them. The GM 3.6 is a great example. 99% of them never get a catch can and live long full lives with no catch-can solvable issues. I know that oil ends up in the intake tract of these, and I agree that it shouldn't and probably wasn't something that the engineers intended.

"Bob, did you make sure to change the design so that some oil gets into the air intake for no particular reason?" - said nobody ever.

Then, once they discovered this, they probably tried to resolve it without major design changes, then whatever was left over was weighed against cost and impact and they made a decision.

That being said: I've seen many 3.6'* what do this and it causes no harm that I can tell.

Again, my opinion above is my opinion, and if anyone intends to lambaste me for it, please at least be nice about it. I've seen a lot of passion around the subject of catch cans for some reason.

Hello - Thank you for responding.

Yes - There are two valves in the catch can IN and OUT. I ran a hose from pcv valve to the IN of the catch can and from OUT to the crank case. Thank you for your opinion. I think I'm going to remove the catch can for now.

Looks like this one:

I don't see instructions on how to plumb it, but based on this:





. . . it would seem like "IN" should be connected to the crankcase. Also, I don't like the idea of one-way valves on oil catch cans. If a vacuum is ever formed in the crankcase, it causes air (with all that'* included) to be sucked in elsewhere.

Glad you're taking it out.