ok I have a 2000 civic si with a JDM B16A that replaced the stock B16A2 which spun a bearing. ever since I replaced the motor, I have been leaking oil from the black box on the back of the block. i have replaced the o-ring but it still leaks. also, at high RPM i hear a kind of hissing noise that sounds like it is coming from the passenger foot well, which is right where that black box is. usually starts hissing around 7K and gets louder up to redline.

so i need schooling. I have searched and found that the black box is a vapor canister, and is part of the PCV system. so where is the PCV valve, in that box? If the PCV valve were bad on my car, would that cause the oil leaking and weird hissing sound? or do i just need to convert to a catch can set up? I read other people have had to do this, even on mostly stock vehicles. other than the swapped motor, which admittedly has a higher CR at 10.4 instead of 10.2, it is all stock 2000 si. stock ecu, intake manifold, exhaust, etc. would you think I needed to switch to a catch can just because of the higher CR of the JDM motor? or something else? or i'm barking up the wrong tree?

Thanks in advance.

 

The PCV is a 90deg fitting between runners 3 & 4 on the IM. It is simply a one-way check valve. This protects air/pressure from going from the intake system to the crankcase. PCV/OEM oil canister diagram (PCV is #6):



The vapor canister is attached to the fuel system. It has an electronic solenoid (purge control solenoid) that allows excess fuel vapor to enter the intake plenum. This is not likely to cause hissing.

I had a motor a few years back where the black oil accumulator had a leak. The bracket that is tack-welded to the body had a leak around one of the welds. Spent weeks trying to source the leak and ended up using ultraviolet dye. Replaced the black box and no more problems.

 

ok, this is why i needed schooling. thanks for the response. So it seems i am mixing terms. I had heard of the black box referred to as a vapor canister in one thread while searching, but maybe I mis-read. so the vapor canister is the charcoal canister? for fuel vapors from the gas tank right?

ok then, also it sounds like the PCV valve isn't likely to cause the hissing or leaking either. so, beyond it being cracked, what could be a cause of that accumulator leaking? or the hissing sound that I believe is coming from the accumulator?

 

the breather box is a way for your motor to release the crank case psi. if ur running an after market IM and you took of the IM support bracket then the box will have a lot of movement. the IM bracket holds the top part of the box from moving. on my race motor, i use honda bond in addition to the oring (i do not cove the ring the honda bond is a secondary seal and it has worked great.) the box allows the oil it catches to return to the oil pan. if the motor have bad ring and the crank case psi goes up it cant fill the box but i have only see this happen a few time. i have ran a motor without the tube on the box and i have never heard a hissing noise.

have u use break cleaner to check for vacum leaks?

have u looked into ur air intake tubing, and seen any oil?

just a few thoughts hope they can help.