OK, this only happens when the engine is cold/has sat over night... as the engine is warming up, the RPM fluctuate... it'll sit at 1500 (approx) then drop to 750 for about half a second, then rev back up to 1500... When the RPM drops, white smoke comes out of the tailpipe... it only happens as the RPM is dropping, not on the way up... IS THIS NORMAL? It will eventually level off to a nice clean idle once the engine is fully warmed up, with no smoke then...
I need some help guys... plz?

 

my car did that for a while, then my coolant seals went bye bye. I am just now getting it back on its feet.

 

Mine does that, only with blue smoke, since it's the oil seals that are shot. It's eventually going to need a rebuild, but until that day, I just have to put up with the smoke.

 

My smoke is kinda whitish-blue...