2008 CADILLAC STS engine overheat

{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 5-11for 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 3-80for
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 3-67andEngine Coolant
Temperature Warning Light on page 3-66for more
information.
5-29

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 5-31for 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. SeeOverheated Engine
Protection Operating Mode on page 5-31for
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.
5-30

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 5-18.
5-31

{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 are not, your vehicle needs service.Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-31for information on driving to a safe place
in an emergency.
Notice:Using coolant other than DEX-COOL®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the warranty. Always
use DEX-COOL
®(silicate-free) coolant in the vehicle.
5-33

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at the FULL COLD/FROID
line on the side of the coolant surge tank, add a
50/50 mixture of clean, drinkable water and 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 5-25for 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 the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
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.
5-34

{CAUTION:
Turning the Intercooler System pressure cap
when the engine and intercooler are hot can
allow steam and scalding liquids to blow out
and burn you badly. Never turn the Intercooler
System pressure cap, even a little, when the
engine and intercooler are hot.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
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.
5-37

Customer Assistance Information (cont.)
Roadside Service.......................................... 7-6
Service Publications Ordering Information........7-15
DDaytime Running Lamps..................................3-37
Defensive Driving............................................. 4-2
Disc, MP3....................................................3-112
Doing Your Own Service Work........................... 5-4
Door
Locks........................................................2-14
Power Door Locks.......................................2-14
Programmable Automatic Door Locks.............2-15
Rear Door Security Locks.............................2-15
Driver Information Center (DIC).........................3-74
DIC Operation and Displays..........................3-74
DIC Warnings and Messages........................3-80
Other Messages..........................................3-97
Driving
At Night.....................................................4-18
Before a Long Trip......................................4-20
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Highway Hypnosis.......................................4-20
Hill and Mountain Roads..............................4-21
In Rain and on Wet Roads...........................4-19
Rocking Your Vehicle to Get it Out.................4-26
Winter........................................................4-22
Dual Climate Control System............................3-48
E
EDR .............................................................7-16
Electrical System
Add-On Equipment.....................................5-116
Fuses and Circuit Breakers.........................5-117
Headlamp Wiring.......................................5-117
Power Windows and Other Power Options....5-117
Rear Underseat Fuse Block.........................5-121
Underhood Fuse Block...............................5-118
Windshield Wiper Fuses.............................5-117
Engine
Air Cleaner/Filter.........................................5-23
Check and Service Engine Soon Light............3-68
Coolant......................................................5-25
Coolant Heater............................................2-31
Coolant Temperature Gage...........................3-67
Coolant Temperature Warning Light................3-66
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-11
Exhaust.....................................................2-38
Oil .............................................................5-18
Oil Life System...........................................5-21
Overheated Protection Operating Mode...........5-31
Overheating................................................5-29
Running While Parked..................................2-39
Starting......................................................2-29
4

Oil, Engine Oil Life System..............................5-21
Older Children, Restraints................................1-28
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-17
OnStar
®System, see OnStar®Manual...............2-48
Operation, Universal Home Remote System........2-52
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-54
Outlets
Accessory Power.........................................3-46
Outside
Automatic Dimming Mirror.............................2-44
Convex Mirror.............................................2-44
Parallel Park Assist Mirror.............................2-44
Power Heated Mirrors..................................2-43
Overheated Engine Protection Operating Mode.....5-31
Owner Checks and Services.............................. 6-9
Owners, Canadian............................................... ii
P
Paint, Damage..............................................5-114
Panic Brake Assist..........................................4-12
Parade Dimming.............................................3-41
Park Aid........................................................2-45
Park Brake....................................................2-35Park (P)
Shifting Into................................................2-36
Shifting Out of............................................2-37
Parking
Assist........................................................2-45
Over Things That Burn.................................2-38
Passenger Airbag Status Indicator.....................3-61
Passenger Compartment Air Filter.....................3-55
Passenger Sensing System..............................1-60
Passing.........................................................4-16
Perchlorate Materials Requirements, California....... 5-4
Power
Door Locks.................................................2-14
Electrical System.......................................5-117
Inadvertent Battery Saver.............................3-43
Lumbar Controls........................................... 1-2
Reclining Seatbacks...................................... 1-4
Retained Accessory (RAP)............................2-29
Seat............................................................ 1-2
Steering Fluid.............................................5-39
Tilt Wheel and Telescopic Steering Column......... 3-7
Windows....................................................2-20
Privacy..........................................................7-16
Event Data Recorders..................................7-16
Navigation System.......................................7-17
OnStar.......................................................7-17
Radio Frequency Identication.......................7-17
Programmable Automatic Door Locks.................2-15
9