Explain to me what is in my catch can.
 

So until now this motor has NEVER had blowby of any sort other than a bit of water condensation (tiny amount) build up here and there. Daily driving, autoX or track stuff. Just never had any to even be remotely concerned about.

I noticed today that there was some stuff in the view tube so I opened it up and poured what seemed like %60 gas %40 froth out.

Here is a terrible photo it dosen't show it that well but more than half of that is basically gas and smells like it too.

Any ideas? Keep in mind this is just from daily driving with the *odd* pull to redline (not a whole lot recently just put putting around). I've smelled my oil on the dipstick as best I can and I don't smell any fuel. So it's coming from somewhere but it does not seem as though the oil is fuel diluted.

https://www.miataturbo.net/attachmen...ine=1335837250

Wow thats picue makes me hard


I say try to lifght it on fire. See how it smells. U know what gas vs oul vs wd40 amel like right? If not now is youe chance to find put!!!!

Yes of course. I already poured it out.

Wait did you really light it on fire? if so i love you

I lit up the residual left overs after I poured the majority out. It's gas. No doubt.

does your coolant look the same?

A leaking injector would put fuel in your oil after you shut the engine off and there's residual fuel pressure.

Are you still running the fuel tank vapor purge system? To your catch can..?

Thats odd to me.

Burning what is in your catch can can be tons of fun.
https://www.miataturbo.net/attachmen...ine=1335876948

Headgasket on it's way out maybe...

This might help
www.miataturbo.net/showthread.php?t=55244

My catch can is only pint-sized (literally...it holds one pint), and I find that it will never accumulate anything during the summer months, but in the winter months, it will accumulate about half a pint per tank of gas.

No tsnk purge and coolant looks fine. Running arp studs and a cometic gasket. I find it hard to belive a fulty hgasket is to blame. Well see how it goes for the next few days...

I had same stuff in my catch can. Turn out to be massive blow-by caused by worn cylinder walls

leak down is less than %10. Not rings. and the motor was fine when I parked it in August. motor is more or less pretty new and was broken in correctly.

How is the catch can hooked up?

Have you check the Vac line to the FPR?

I am not sure how, if the FPR has a hole in the diaphram, how it would make it to your CC

I'll have to check that. It's an aeromotive and fairly new but I guess anything is possible.

Catch can is hooked up direct from my valve cover gasket to a vented can.

I've driven it for a week now and was pretty hard on it a few times and so far it seems like there is nothing in there. Perhaps it was an anomaly of some sort. I'll keep an eye on it and update if I get a repeat.

If it was fuel, that usually means flooding of the cylinders. For example if an injector was going way rich; unburned gas easily gets past the rings. Your catch can should only be picking up stuff that was in the crankcase.

Look into any and all possible ways to get too much fuel into a cylinder. M2cupcar's question is certainly a possibility, for example.

Alternately, look at how fuel could be getting into your catch can via vacuum or hose routing. But my guess is it came from the sump. You could drain the oil and see what it looks like. Maybe splurge $20 on an oil analysis.