Coolant disappearing overnight

How much are you adding? A whole jug or jus a lil bit. Are you blowing white smoke out of the exhaust? When you pull your oil stick out is it covered in oil?

 

What's the make and model of the engine along with year.

 

What did your companies mechanic say?

 

I had the same problem with the same model...turned out to be the bunk heater core was dripping ever so slightly at night while i was parked even though i wasn't running heat.

 

I have that, I am not loosing coolant really, but in the mornings I have white smoke and oil stick is covered in oil, what is it? I have N14

 

I'm thinking cold water leak. check all of your clamps associated with water hoses. run around block when first starting up, then stop to see if coolant has pooled along frame rail or some other place that wont drip down till moving

 

white smoke is coolant leak into motor, to check for head gasket, take a soda bottle, and fill with water. with truck running, take overflow tube from radiator and put down into water. if it blows bubbles, you've got a head gasket leak