Liquid spill: 6500RPM Fan speed, webcam/AirPort card not recognized

I have a MacBook Pro 13" A1278 with liquid damage somehow still affecting it in a weird way, although the liquid (redwine) did not enter through the keyboard, as it was covered by a rubber-coating I have. The liquid was on the keyboard, but went towards the screen and down back into the area where the air comes out.

The machine have had the DC-In board replaced, which solved the charging problem it had. In addition it has been taken apart twice and cleaned completely.

Problem:

The fan runs at high speed at 45 degrees celsius, and AirPort card and webcam is not recognized - HOWEVER, if I power down, remove the bottom panel and power up again, everything is working fine!

Question:

What causes this to happen? I have tried to cover the entire inside of the backpanel with tape so nothing from the logic board touches the bottom panel, but it's the same. I also tried placing the bottom panel loosely on the back whilst having the laptop standing on the side; this works unless I press is up against the bottom to fit it correctly.

Any suggestions?