Can one of the listsages please set me straight? I've seen posts from several people "doing the vacuum test" by pulling dipsticks or opening oil filler caps, on their NA engines. Isn't this test only valid on turbo cars? My NA runs the same with all ports open, so I just figured that the turbos do something differently. Thanx in advance for the info! >>>>>Bernie QCUSA #1765 Member #47 NW Region AQC