I have heavy white smoke coming from my tailpipe. My truck is also idling roughly.
Your engine is getting coolant into it and producing the white smoke out the tail pipe. The coolant could be getting into the motor from the intake, head gaskets, or head crack. The system would need to be checked to determine where the leak is coming from. Have a certified technician come and test the vehicle for you. They will be able to come to your location and make the repairs that are needed to resolve this issue.