Cadillac CTS-V 2009 Owner's Manual page 346

Checking Coolant in the Intercooler
System (CTS-V)
The vehicle must be on a level surface when checking
the coolant level.
The super charged engine intercooler coolant fill bottle
is located in the engine compartment on the passenger
side of the vehicle. See Engine Compartment
Overview on page 5-14.
Check to see if coolant is visible in the coolant fill bottle.
If the coolant inside the coolant fill bottle is boiling, do not
do anything else until it cools down. If coolant is visible
but the coolant level is not at or above the COLD FILL
mark, add a 50/50 mixture of clean, drinkable water and
®
DEX-COOL coolant at the coolant fill bottle, but be sure
the cooling system is cool before this is done.
If the engine is warm or hot, the coolant level should be
at or above the COLD FILL line on the side of the coolant
fill bottle. If the engine is cold, the coolant level should be
near the COLD FILL line on the side of the coolant fill
bottle. If it is not, you could have a leak in the cooling
system.
5-36
Adding Coolant to the Intercooler
System Coolant (CTS-V)
1. Remove the intercooler system pressure cap when
the intercooler system hoses are no longer hot.
Turn the pressure cap slowly counterclockwise
about one-quarter of a turn. If you hear a hiss, wait
for that to stop. This allows any pressure still left
to be vented.
2. Then keep turning the pressure cap slowly and
remove it.