2006 CADILLAC STS engine overheat

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.
{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 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.
5-33

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 5-26for 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. 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.
5-34

How to Add Coolant to the
Intercooler System Fill Neck
(4.4L V8 STS-V Engine Only)
If you have not found a problem yet, turn the engine off
and allow it to cool down, then check to see if coolant is
visible within the horizontal tube section of the ll neck.
If coolant is not visible, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant to the ll neck.
Be sure the Intercooler System, including the Intercooler
System pressure cap, is cool before doing so. See
Engine Coolant on page 5-26for more information.
{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 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: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.
5-37

Engine
Air Cleaner/Filter.........................................5-24
Battery.......................................................5-44
Check and Service Engine Soon Light............3-67
Coolant......................................................5-26
Coolant Heater............................................2-27
Coolant Temperature Gage...........................3-67
Coolant Temperature Warning Light................3-66
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-39
Oil .............................................................5-18
Oil Life System...........................................5-22
Overheated Protection Operating Mode...........5-31
Overheating................................................5-30
Starting......................................................2-25
Entry Lighting.................................................3-39
Event Data Recorders (EDR)............................. 7-8
Extender, Safety Belt.......................................1-26
Exterior Lighting Battery Saver..........................3-38
F
Filter
Engine Air Cleaner......................................5-24
Finish Damage.............................................5-101
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass.................................................3-12
Flat Tire........................................................5-81
Flat Tire, Changing.........................................5-83
Flat Tire, Storing.............................................5-92
Fluid
Automatic Transmission................................5-26
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp Light..............................................3-71
Fog Lamps ....................................................3-37
Forward Collision Alert (FAC) System.................. 3-9
Front Axle......................................................5-52
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage .........................................................3-72
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Fuses
Fuses and Circuit Breakers.........................5-105
Rear Underseat Fuse Block.........................5-110
Underhood Fuse Block...............................5-106
Windshield Wiper.......................................5-104
5

O
Odometer......................................................3-59
Off-Road Recovery..........................................4-15
Oil
Engine.......................................................5-18
Pressure Light.............................................3-70
Oil, Engine Oil Life System..............................5-22
Older Children, Restraints................................1-26
Online Owner Center........................................ 7-3
OnStar
®System, see OnStar®Manual...............2-45
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-54
Outlet(s), 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.............................. 6-8
Owners, Canadian............................................... ii
P
Paint, Damage..............................................5-101
Panic Brake Assist..........................................4-12
Parade Dimming.............................................3-39Park Aid........................................................3-44
Park (P)
Shifting Into................................................2-36
Shifting Out of............................................2-38
Parking
Assist........................................................3-44
Brake........................................................2-35
Over Things That Burn.................................2-38
Passenger Airbag Status Indicator.....................3-61
Passenger Compartment Air Filter.....................3-55
Passenger Sensing System..............................1-59
Passing.........................................................4-15
Power
Accessory Outlet(s)......................................3-46
Door Locks.................................................2-12
Electrical System.......................................5-105
Inadvertent Battery Saver.............................3-40
Lumbar Controls........................................... 1-2
Reclining Seatbacks...................................... 1-4
Retained Accessory (RAP)............................2-25
Seat............................................................ 1-2
Steering Fluid.............................................5-39
Tilt Wheel and Telescopic Steering Column....... 3-6
Windows....................................................2-18
Pretensioners, Safety Belt................................1-25
Programmable Automatic Door Locks.................2-13
9