Car starts immediately smoking blue out of exhaust approximately one time in a month. Smokes hard. I see it from mirror. Only way to stop it is to shut down engine and start again 1-2 minutes after. Everything will be normal. Hyundai sonata 2.0 crdi 2006 137 000 km
Oil smoke for several seconds on start is the definition of valve stem seal failures. Also assuming general oil consumption is low . When the engine is off ,a little oil seeps down the valve stems , when started any leaked oil burns off at one time . While running this oil seepage is so small that you do not notice it. I had a Chevy Vortec V-6 that did it, I bought the seals ( cheap rubber "O" rings) but decided it was too much work to put them in . So I just put in a quart of oil about every 3000 miles.