<VV> white smoke

[Pete]

I was driving along at aprox 60 mph when white smoke blew from the exhaust. A similar situation happened a few years ago when I blew an exhaust valve so I did a compression check to determine if I had the same problem. All the cylinders tested within 5 lbs. of each other [135 to 140]. I  then changed the modulator valve and test drove it. Ran fine up to 58 mph when it "hit the wall" for a second at 60 mph and again lots of white smoke. when I slowed down to 50 mph it ran fine. Checked both trans.fluid and oil,both levels ok. There was some oil blow by at the dip stick. Last week I changed the oil and filter and added a few ounces of brake fluid to the oil.I had read in the Tech Manual that this was good for all the seals [both fluids are synthetic].
     Any ideas?  
    Pete