coolant CADILLAC STS 2007 1.G User Guide

After you have removed the sight shields (if equipped) on the 4.4L V8 STS-V engine, here is what
you will see:
A. Battery. SeeBattery on page 408.
B. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 488.
C. Passenger Compartment Air Filter. See
Passenger Compartment Air Filter on page 239.
D. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 404.
E. Intercooler System Pressure Cap. SeeEngine
Coolant on page 389.
F. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 403.
G. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 380.
H. Engine Oil Dipstick (Out of View). See
“Checking Engine Oil” underEngine Oil on
page 380.I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 405.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 393andCooling System on page 396.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 386.
If your vehicle is equipped with front compartment
underhood sight shields, before closing the
hood be sure to reinstall the sight shields. To
reinstall the shields, locate the tabs on the left and
right sides and insert them into the openings in
the tower to tower brace. Then insert the fasteners
into the top of the shield and push the fasteners
back into place.
379

Engine Air Cleaner/Filter
The engine air cleaner/lter is in the engine
compartment on the driver’s side of the vehicle,
near the front. SeeEngine Compartment Overview
on page 373for more information on locating
the air cleaner/lter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change
after each 50,000 mile (83 000 km) interval. See
Scheduled Maintenance on page 505for more
information. If you are driving in dusty/dirty
conditions, inspect the lter at each engine
oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/lter remove the lter
from the vehicle and lightly shake the lter to
release loose dust and dirt. If the lter remains
caked with dirt, a new lter is required.
To inspect or replace the lter in the 3.6L V6 or
4.6L V8 engines, do the following:
1. Remove the two screws located on the top of
the cover.
2. Disconnect the coolant recovery hose so that
it is not going across the top of the engine air
cleaner/lter.
4.6L V8 Engine shown, 3.6L V6 Engine similar
386

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 ve 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 393.
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 the rst maintenance service after
each 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.
389

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not 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.
If you have to add coolant more than once or
twice a year, have your dealer check your cooling
system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system, you
could damage your vehicle. Use only the
proper mixture of the engine coolant listed in
this manual for the cooling system. See
Recommended Fluids and Lubricants on
page 516for more information.
390

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. See
Engine Compartment Overview on page 373for
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.
391

Checking Intercooler System Coolant
(4.4L V8 STS-V Engine Only)
SeeEngine Compartment Overview on page 373
for the location of the intercooler system
pressure cap.Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure
could cause your engine to overheat and
be severely damaged.
Park the vehicle on a level surface and turn off the
engine. When the engine is cold, the coolant
level should be visible in the intercooler ll neck.
Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the intercooler ll
neck, but only when the engine is cool. See
Cooling System on page 396for instructions on
how to add coolant to the intercooler ll neck.
392

{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.
When replacing a pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is properly
and tightly secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 373for more
information on location.
Engine Overheating
There are two engine hot messages that could be
displayed in the Driver Information Center (DIC).
SeeDIC Warnings and Messages on page 264for
more information.
If the engine is overheating, then you will nd a
coolant temperature gage and a coolant warning
light on the instrument panel. SeeEngine
Coolant Temperature Gage on page 251and
Engine Coolant Temperature Warning Light on
page 251for more information.
393

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can
burn you badly, even if you just open the
hood. Stay away from the engine if you
see or hear steam coming from it. Turn it
off and get everyone away from the
vehicle until it cools down. Wait until
there is no sign of steam or coolant
before you open the hood.
If you keep driving when the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the engine
is cool.
SeeOverheated Engine Protection
Operating Mode on page 395for
information on driving to a safe place in
an emergency.Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
on page 395for information on driving to a
safe place in an emergency.
If No Steam Is Coming From
Your Engine
An overheat warning, can indicate a serious
problem.
If you get an engine overheat warning but see or
hear no steam, the problem might not be too
serious. Sometimes the engine can get a little too
hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
394

If you get the overheat warning with no sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to do
so, pull off the road, shift to PARK (P) or
NEUTRAL (N) and let the engine idle.
2. Set the climate controls to the highest heat
setting and fan speed and open the windows,
as necessary.
If the coolant warning light is not on or the coolant
temperature gage does not indicate the engine
is overheating, you can drive. Just to be safe, drive
slower for about 10 minutes. If the warnings do
not come back on, drive normally.
If the warnings continue and you have not stopped,
pull over, stop, and park the vehicle right away.
If there is still no sign of steam, idle the engine for
three minutes while parked. If the warnings are
still indicated, turn off the engine and get everyone
out of the vehicle until it cools down. Also, see
“Overheated Engine Protection Operating Mode”
later in this section.
You might decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be
driven to a safe place in an emergency. Should an
overheated engine condition exist, an overheat
protection mode which alternates ring groups of
cylinders helps prevent engine damage. In this
mode, you will notice a loss in power and engine
performance. An engine overheat warning will
indicate that an overheat condition exists. Driving
extended miles (km) and/or towing a trailer in
the overheat protection mode should be avoided.
Notice:After driving in the overheated
engine protection operating mode, to avoid
engine damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss and change the oil. SeeEngine Oil on
page 380.
395

Cooling System
When you decide it is safe to lift the hood, this is
what you will see:
A. Engine Cooling Fans
B. Coolant Surge Tank and Pressure CapSome vehicles may have an engine driven fan, as
well as the electric pusher fans which are
located behind the vehicle’s grille.
{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, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
When the engine is cold, the coolant level
should be at or slightly above the FULL
COLD/FROID line on the side of the coolant surge
tank. If it is not, 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.
3.6L V6 Engine shown, 4.6L V8 and 4.4L V8 STS-V
Engines similar
396