Carrier unit started blowing white smoke. When you crank up the unit, is OK, after an hour of the unit been running it starts blowing white smoke for 3-4 seconds and the unit goes back to normal, no noise, no more smoke. But then every so often it does it again in a period of 15 minutes to 1 hour, same thing...blows smoke 304 seconds and then normal. When the unit is in idle, everything is normal as soon as the compressor kicks in it takes about 10-15 minutes for that white smoke to blow for 3-4 seconds. Thank you for any help