Time to rebuild?
If I push the fan blades without also pulling on the belt, the belt just slips. Maybe it's not tight enough or maybe it's too covered in power steering fluid that has leaked out of the pump. Anyway, I was able to get a small fraction of a turn at a time by pulling on the belt with one hand and pushing the fan with the other. It helped to remove the coolant overflow bottle. I did feel the "air springs" but I couldn't tell for sure if there were 3 per revolution because I couldn't turn it fast enough. I'd hear hissing for a second or two, then on the next pull I might get another second or two of hiss, then nothing until the next cylinder. The bottom line is, as AJ said, I can't really tell anything from that method.
I'm just trying to understand how the compression can be so good if there's enough pressure in the crankcase to push air the wrong way through the breather.
I added 2 cans of BG 44K when I filled the gas tank today. Per Dan's recommendation, I'll let that work for a while and then do the Italian tuneup. I did notice that my spark plugs were a much lighter color after a couple of good highway trips than they were last time I looked at them. Previously they were brownish, today more of a light tan or yellow.
My typical commute is about 15-25 minutes depending on traffic, and the engine coolant always reaches 190 degrees according to the gauge. I know it takes more high-power running to get all the components up to full temperature. Anyway, I'm going to make sure I mix in some longer, higher speed trips from now on.