I did a quick experiment yesterday to see what actually comes out of my crankcase breather.

I took the hose off the pipe that is attached to the breather and stuck a long tube on it. I ran this out from the front of the car and into a cup. I then let the car idle for about 20 minutes (at the same time I was monitoring the exhaust temperature, but that's a different story).

I ended up with 2 tablespoons of yellowish water.

In my ignorance of these matters, I came to the conclusion that I was happy because there seemed to be little oil in the water, but unhappy at the thought that this water would normally be sent back into the left intake manifold to go through the engine all over again.

Certainly building a homemade vapor/water separator (vapor to be sent back to the intake, water to be overboarded) wouldn't be a hard task, but am I worrying about something here that I shouldn't be worrying about.

Thanks,

John
1987 XJS V12, (supposedly) 62,000 miles

 

The water goes through the intake, into the combustion chamber, and out the exhaust.

Only a very small part of it might be recycled as blowby gas.

Try the same experiment after a long drive when the condensation has been boiled off.