2004 CADILLAC CTS cooling

A. Underhood Fuse Block. SeeFuses and Circuit
Breakers on page 5-100.
B. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-41.
C. Battery. SeeBattery on page 5-45.
D. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-40.
E. Engine Oil Fill Cap. SeeEngine Oil on page 5-18.F. Engine Oil Dipstick. SeeEngine Oil on page 5-18.
G. Brake Master Cylinder Reservoir. SeeBrakes
on page 5-42.
H. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-31
andCooling System on page 5-34.
I. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-24.
5-15

A. Underhood Fuse Block. SeeFuses and Circuit
Breakers on page 5-100.
B. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-41.
C. Battery. SeeBattery on page 5-45.
D. Engine Oil Dipstick. SeeEngine Oil on page 5-18.
E. Engine Oil Fill Cap. SeeEngine Oil on page 5-18.
F. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-40.G. Brake Master Cylinder Reservoir. SeeBrakes on
page 5-42.
H. Hydraulic Clutch Reservoir. SeeHydraulic Clutch
(Manual Transmission) on page 5-28.
I. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-31
andCooling System on page 5-34.
J. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-24.
5-17

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs rst, if you add
only DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 5-31.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant which won’t damage
aluminum parts. If you use this coolant mixture,
you don’t need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
5-29

If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Checking Coolant
The coolant surge tank and pressure cap are located on
the driver’s side of the vehicle, toward the rear of the
engine compartment. SeeEngine Compartment
Overview on page 5-12for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD/FROID line on the side of the surge tank.
Follow the arrow from the top of the tank down the
side to the horizontal mark.
If the Check Coolant Level message in the DIC
comes on and stays on, it means you’re low on
engine coolant. SeeDIC Warnings and Messages
on page 3-70for more information.
5-30

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Surge Tank and Pressure Cap
B. Electric Engine Cooling Fans{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.
3.2L V6 shown
5-34

The coolant level should be at or slightly above the
FULL COLD/FROID line on the side of the coolant surge
tank. If it isn’t, you may have a leak at the pressure
cap or in the radiator hoses, heater hoses, radiator,
water pump or somewhere else in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant.
That could cause an engine re, and you could
be burned. Get any leak xed before you drive
the vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine is overheating, both fans should be
running. If they aren’t, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-35

How to Add Coolant to the Coolant
Surge Tank
If you haven’t found a problem yet, check to see if coolant
is visible in the surge tank. If coolant is visible but the
coolant level isn’t at the FULL COLD/FROID line on the
side of the coolant surge tank, add a 50/50 mixture of
clean, drinkable waterand DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is cool
before you do it. SeeEngine Coolant on page 5-29
for more information.
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly.
They are under pressure, and if you turn the
coolant surge tank pressure cap — even a
little — they can come out at high speed.
Never turn the cap when the cooling system,
including the coolant surge tank pressure cap,
is hot. Wait for the cooling system and coolant
surge tank pressure cap to cool if you ever
have to turn the pressure cap.{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will.
CAUTION: (Continued)
5-36

CAUTION: (Continued)
Your vehicle’s coolant warning system is set for
the proper coolant mixture. With plain water or
the wrong mixture, your engine could get too
hot but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.If no coolant is visible in the surge tank, add coolant
as follows:
1. Park the vehicle on a level surface. You can
remove the coolant surge tank pressure cap
when the cooling system, including the coolant
surge tank pressure cap and upper radiator hose,
is no longer hot. Turn the pressure cap slowly
counterclockwise (left) about one-quarter turn
and then stop.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
5-37