Cummins ISX 485 While Coolant smelling exhaust smoke

So I bought this truck with a Cummins ISX 485.

Turns out that it emits copious amounts of white smoke which smells of coolant:



However, I noticed that it only seems to do it at idle, if I push the gas pedal hard, the smoke disappears temporarily.

I first suspected blown head gasket. After some thinking, I started suspecting that perhaps this is a leaking EGR cooler, since EGR is used when the engine is not loaded? Any thoughts?

Thanks!

 

This is a really smart idea, I will do it!

 

Here's something interesting. I added some coolant and water today just to be on the level. Started the truck.

To my surprise, the truck started and did NOT emit any white smoke!

I could run it for a bit longer, but I have a feeling that it starts smoking only after it gets WARM. Anything that can be gleaned from this?