While I have searched this issue and learned a great deal from all of you, I would appreciate any further ideas you may have to help diagnose the probable cause or cure for blue smoke from my recently acquired Monte. Its the 3.0l, 1990, LWB, 180KM, auto, with good compression on all 6 cylinders (between 135-145 psi.) I recently replaced the valve stem seals and noted the guides were OK and had been updated with retaining clips but I still have clouds of blue smoke starting about 10 seconds after startup and lasting for only a couple minutes or blocks plus it puffs blue once under hard acceleration. It doesn't visibly smoke at idle or stoplights. I disconnected the PCV hoses with no effect. By elimination, I am thinking its worn/plugged oil control rings even though the compression rings must be OK? I tried Alemite CD2, overnight soaks in Marvel MO and ATF, and Sea Foam in the oil for 100 miles. No improvement evident and the CD2 made it smoke continuously. Any help, ideas, or questions would be appreciated and thanks for reading this long description. <img src="/forums/images/graemlins/confused.gif" alt="" />