i want to find a oil leak so i want to pressurizing the crankcase and spray soapy water to find bubbles around the oil pan area .
first i know you seal off the pcv and beather
can you add air thur the dipstick
also do you need to be tdc for valve to be closed
can i set my tank to 15 lbs or so will this be safe . than you

I wouldn't start with 15, more like five or so. If you don't find anything move it up 10.

the valves won't enter into this, this is crankcase.

How about cleaning the engine, then putting some dye in the oil to check with a UV light? That's the more common way to find leaks these days.

http://autorepair.about.com/od/otherodddiyjobs/a/findleaks_2.htm