Blue smoke at specific time when warming up.
 

Hi,

I've got a weird issue about my 1972 350SL 4.5. 209,000 miles, original engine. The car starts well, runs well both warm and cold, but it does one strange thing from time to time.
When the car is cold and I drive it, after going about 1 mile I come to a stop sign. When I take off from that stop sign it sometimes blows out a large cloud of blue smoke for about 5 seconds. After that it runs fine. It is during this part of "warming up" that this problem happens. Except for this, I never see blue smoke come out of the exhaust. I can only assume that this is a a point when a thermostat switches something tied to the warm up process, but I can't figure out where or how it seems to "store" this bit of oil that blows out the back at this particular time. It does not blow smoke any other time, and does not lose much oil over the course of an oil change.

If anyone has any idea of what is happening, I would sure like to hear from you.

Thanks