Coolant leak out exhaust at cold startup

[Rawze]

Coolant issues...

You could check it for any kind of rapid pressure buildup when engine brakes are on or while engine is under heavy load. Installing a pressure test kit and extending the hose long enough so that you can put the gauge in the cab temporarily will let you do this.

If you suspect a leak then when not driving it ...
Pressure test it to 20 psi and let it sit overnight. Check for coolant inside the intake and exhaust of turbocharger, in the back side of the egr cooler, and around the doser injector after sitting all night. Also check for external leaks and check the tranny for coolant buildup if it has a coolant type heat exchanger. Sometimes the coolant level in the tank does not drop even though you have a leak. Never trust the fact the coolant level is not dropping when doing pressure testing. Pressure testing can find leaks that only seep a bit when the engine is not running, so the level will not noticeably change in the bottle.

If an internal leak is suspected, you can pull the oil pan, wipe everything down good at the bottom of the engine, pressurize the coolant system to it to 20 psi and let it sit overnight. Look for coolant around the bottom of the liners and pistons next day. Sometimes you will only find a tiny drop or 2 mixed with oil at the bottom of a rod cap or other component. You have to take a hard look but those types of problems can always be found before pulling the engine apart.