Cadillac 2016 CT6 Owner's Manual page 279

278 Vehicle Care
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
2.0L L4 and 3.0L V6 Engine
Coolant Surge Tank
3.6L V6 Engine Coolant
Surge Tank
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. See Engine
Overheating 0 280.
The coolant surge tank is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment
Overview 0 265.
How to Add Coolant to the
Coolant Surge Tank
Caution
This vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible but
the coolant level mark is not visible,
add a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant at the coolant surge tank to
the top rib on the middle of the tank,
but be sure the cooling system,
including the coolant surge tank
pressure cap, is cool before this is
done. See Engine
Overheating 0 280.