Oil Bypassing Catch Can(Damond) - Smoke On Throttle Off (S280 High Boost)

[AthenaAutocross]

Alright, I'm finally opening a thread because I'm losing my mind trying to read what I should do to resolve this.

I've had this issue for a bit now. Currently I'm using a Damond catch can with check valve (I also have a UPR check valve sitting on my bench). For daily driving it's very much less noticeable but for autocross It happens frequently from the high boost. I'll be wide open throttle with no smoke, but as soon as I get off throttle and the vacuum is applied I get a poof of smoke out the exhaust, I'll also on occasions for cool down time get some smoke in the grid idle. It's not always drastic but only ever really happens off a hard WOT. I'm trying to fully prevent it so I don't ingest butt loads of oil on my E50 tune. Supposedly adding the VTA option on the can can help resolve this, I have one on the way this week but I'm checking if anything else can be done to resolve it.

I read Dizzies guides which weren't super helpful for this problem and I've seen non responded to thread questions posted here on similar issues but no answer.

I've thought it was maybe my hot side seals when I first replaced my broken PCV hose with a straight one, but going to the catch can and fixing my manifold bolts, valve cover gasket and Vband on the S280 solved everything else.

 

[Grsemky]

Have you verified the check valve is in the right orientation? I'm a firm believer in the k.i.s.s. method... you could try adding a second catch can in-between the crossover and valve cover? It's a low pressure zone so I doubt that's it but you could at least add a breather for science🤷🏼‍♂️

 

[AthenaAutocross]

Have you verified the check valve is in the right orientation? I'm a firm believer in the k.i.s.s. method... you could try adding a second catch can in-between the crossover and valve cover? It's a low pressure zone so I doubt that's it but you could at least add a breather for science🤷🏼‍♂️

I did, It's blow smoke like this on both the URP and Damond check valves. The valves are only preventing boost from going up the stream, the down stream still flows on vacuum so it'll pull oil. Supposedly there's another valve inside of the valve cover but I couldn't really see it when I had it off.

 

[Grsemky]

Tricky... Did it puff smoke on off throttle with that Amazon special you had mounted up front? Maybe your Damond is mounted in a way that is causing it to siphon out of the reservoir

 

[AthenaAutocross]

Tricky... Did it puff smoke on off throttle with that Amazon special you had mounted up front? Maybe your Damond is mounted in a way that is causing it to siphon out of the reservoir

That one did too, it had a lot of oil going into it for the short amount of time I had it.

 

[Grsemky]

Double hmmmmmm....