Pressure Tester (was Surging and erratic boost

[PeterBergin at aol.com]

Curious, I have never heard of a check valve their.  Would like to  find out. 
 The dipstick has a couple of O-rings on it.  That might be  why my car 
(chipped) seldom sees over 1.6 on the dash gauge.  Once in a  blue moon I will get 
a sudden surge up to 1.7 or 1.8.
 
Could I be dumping boost into my crankcase?  Never considered it as  possible.
 
Pete