Not sure who is right here but Gtxragtop (Dave) did a test on my dipstick tube to determine CCV function by measuring the amount of vacuum pulled (I can't remember but I think the proper amount is 3"-6" of water). Not sure where this test came from (TIS?). No/low vacuum meant a CCV problem. My understanding is this test measures the amount of vacuum in the crankcase. But I am not sure how the pressure in the sump translates to the pressure in the crankcase. According to this test, the sump should have negative pressure and pull on the balloon, if the CCV is functioning properly. If it inflates the balloon, there is definitely a problem as that would indicate positive pressure in the sump. In addition, positive pressure in the sump should also blow the dipstick out of the hole. In theory the CCV is supposed to keep the crankcase from a positive pressure condition and that a failed CCV will create a positive pressure situation by keeping the crankcase from venting gases. If I sound confused, it is because I am. :dunno: All I know is that I replaced the damn thing and I have stopped burning oil.