[chartmaker]

Car was parked for about 6 months, when engine working it makes some hissing sound like air under pressure coming out of the engine, somewhere around intake.

I have taken off air filter and sleeve and closed up throttle and tubes with plastic bags, then i lit a cigarette and blow smoke in one one of the tubes that connect to intake, smoke started coming out of EGR Valve vent holes, is that normal behavior?

OK just checked to be 100% sure.
Nothing should come out the vent holes. They are just atmosphere to the diaphragm free side. If you suck on the nipple, or put a hose on it to do the same, it should hold, no leaking. If so, it is scrap. Won't function and leaks vacuum.

-chart-