2010 CADILLAC DTS cooling

Cooling System
The cooling system allows the engine to maintain the correct working temperature.
A. Coolant Surge Tank with Pressure CapB. Electric Engine Cooling Fans
4.6L L37 Engine shown, 4.6L LD8 Engine similar
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{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{WARNING:
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 fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
Notice:Using coolant other than DEX-COOL®cancause premature engine, heater core, or radiatorcorrosion. In addition, the engine coolant couldrequire changing sooner, at 50 000 km (30,000 miles)or 24 months, whichever occurs first. Any repairswould not be covered by the vehicle warranty.Always use DEX-COOL®(silicate-free) coolant inthe vehicle.
Engine Coolant
The cooling system in the vehicle is filled withDEX-COOL®engine coolant. This coolant is designedto remain in the vehicle for five years or 150,000 miles(240 000 km), whichever occurs first.
The following explains the cooling system and how tocheck and add coolant when it is low. If there is aproblem with engine overheating, seeEngineOverheating on page 6-27.
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What to Use
{WARNING:
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 fire and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL®coolant.
Use a 50/50 mixture of clean, drinkable water andDEX-COOL®coolant. If using this mixture, nothing elseneeds to be added. This mixture:
•Gives freezing protection down to!34°F (!37°C),
outside temperature.
•Gives boiling protection up to 265°F (129°C),
engine temperature.
•Protects against rust and corrosion.
•Will not damage aluminum parts.
•Helps keep the proper engine temperature.
Notice:If an improper coolant mixture is used, theengine could overheat and be badly damaged.The repair cost would not be covered by the vehiclewarranty. Too much water in the mixture canfreeze and crack the engine, radiator, heater core,and other parts.
Notice:If extra inhibitors and/or additives are usedin the vehicle’s cooling system, the vehicle couldbe damaged. Use only the proper mixture ofthe engine coolant listed in this manual for thecooling system. SeeRecommended Fluids andLubricants on page 7-8for more information.
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Checking Coolant
The vehicle must be on a level surface when checkingthe coolant level.
Check to see if coolant is visible in the coolant recoverytank. If the coolant inside the coolant recovery tank isboiling, do not do anything else until it cools down.If coolant is visible but the coolant level is not ator above the FULL COLD mark, add a 50/50 mixture ofclean, drinkable water and DEX-COOL®coolant atthe coolant recovery tank, but be sure the coolingsystem is cool before this is done. SeeEngine Coolanton page 6-23for more information.
How to Add Coolant to the Surge Tank
{WARNING:
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.
Notice:This vehicle has a specific coolant fillprocedure. Failure to follow this procedure couldcause the engine to overheat and be severelydamaged.
{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
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{WARNING:
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 surge tank
pressure cap — even a little — they can come out
at high speed. Never turn the cap when the
cooling system, including the surge tank pressure
cap, is hot. Wait for the cooling system and surge
tank pressure cap to cool if you ever have to turn
the pressure cap.
If no coolant is visible in the surge tank, add coolantas follows:
1. Remove the coolantsurge tank pressurecap when the coolingsystem, includingthe coolant surge tankpressure cap andupper radiator hose, isno longer hot.
Turn the pressure cap slowly counterclockwise.If you hear a hiss, wait for that to stop. A hissmeans there is still some pressure left.
2. Keep turning the cap and remove it.
3. Fill the coolant surgetank with the propermixture to theFULL COLD markon the side ofthe coolant surge tank.
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4. With the coolant surge tank cap off, start the engineand let it run until you can feel the upper radiatorhose getting hot. Watch out for the enginecooling fans.
By this time, the coolant level inside the coolantsurge tank may be lower. If the level is lower, addmore of the proper mixture to the coolant surge tankuntil the level reaches the FULL COLD mark onthe side of the coolant surge tank.
5. Replace the cap. Be sure the cap is hand-tight andfully seated.
Notice:If the pressure cap is not tightly installed,coolant loss and possible engine damage mayoccur. Be sure the cap is properly and tightlysecured.
If coolant is needed, add the proper DEX-COOL®
coolant mixture at the coolant recovery tank.
Engine Overheating
The vehicle has several indicators to warn of engineoverheating.
There is an engine temperature warning light and/orgage on the instrument panel cluster. SeeEngineCoolant Temperature Warning Light on page 4-55andEngine Coolant Temperature Gage on page 4-56.
The vehicle may also display a ENGINE OVERHEATEDIDLE ENGINE message or an ENGINE OVERHEATEDSTOP ENGINE message displayed in the DriverInformation Center (DIC). SeeDIC Warnings andMessages on page 4-67for more information. You willalso hear a chime.
4.6L L37 Engine shown, 4.6L LD8 Engine similar
6-27

You may decide not to lift the hood when this warningappears, but instead get service help right away.SeeRoadside Service on page 8-7.
If you do decide to lift the hood, make sure the vehicleis parked on a level surface.
Then check to see if the engine cooling fans arerunning. If the engine is overheating, both fans shouldbe running. If they are not, do not continue to runthe engine and have the vehicle serviced.
Notice:Engine damage from running the enginewithout coolant is not covered by the warranty.
Notice:If the engine catches fire while driving withno coolant, the vehicle can be badly damaged.The costly repairs would not be covered bythe vehicle warranty. SeeOverheated EngineProtection Operating Mode on page 6-29forinformation on driving to a safe place in anemergency.
If Steam Is Coming From The Engine
Compartment
{WARNING:
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 fire. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating Mode
on page 6-29for information on driving to a safe
place in an emergency.
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If you need to replace any of your wheels, wheel bolts,wheel nuts, or Tire Pressure Monitor System (TPMS)sensors, replace them only with new GM originalequipment parts. This way, you will be sure to have theright wheel, wheel bolts, wheel nuts, and TPMSsensors for your vehicle.
{WARNING:
Using the wrong replacement wheels, wheel bolts,
or wheel nuts on your vehicle can be dangerous. It
could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use the
correct wheel, wheel bolts, and wheel nuts for
replacement.
Notice:The wrong wheel can also cause problemswith bearing life, brake cooling, speedometer orodometer calibration, headlamp aim, bumper height,vehicle ground clearance, and tire or tire chainclearance to the body and chassis.
If your vehicle is a professional model, the wheels havea unique offset and bolt hole diameter. Each of thewheels on the professional vehicle have eight wheelsnuts. The wheels on the non-professional vehiclehave five wheel nuts. SeeChanging a Flat Tire onpage 6-80for more information.
Used Replacement Wheels
{WARNING:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how far
it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel, use
a new GM original equipment wheel.
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