OK I found it.
The air filter was rubbing the big hoses underneath. Strange that the area around there seems soft and sticky like some chemicals was eating & rubbing the hose for a while and make this tiny hole.
Could it be oil from K&N filter? Filter always look like the way it supposes to be not too oily.
But the dust accumulates at the bottom of the filter that draw the oil to the hose surface could do it
At the autostore, I bought a roll of radiator hose tape (rubber stretchable and stick to itself) and wrapped over the hole for few times. It still leaks under high pressure -- thermostat opened... I probably can fix it if I take the hose out and neatly wrap the tape. There is no room to work the tape there ... whatever works at the moment.
So now I try to really cool down the engine before parking her -- to prevent another pump kicking in after engine shut-off.
Samco hoses will be shipped in few weeks. Then I might need something to hang/hold the air filter in place so it won't be rubbing again.
At the same time, cleaned and oiled K&N filter, patched some holes that I can see through from the inside from dented mesh-net.
Intake sound is noticeable louder after cleaning. She's more willing to rev too.
