2009 CADILLAC DTS engine

Checking the Fluid Level
Prepare the vehicle as follows:
1. Park the vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in P (Park).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position
the shift lever in P (Park).
4. Let the engine run at idle for three to ve minutes.
Then, without shutting off the engine, follow these steps:
1. Locate the transmission uid cap which is located
next to the radiator hose and below the engine air
cleaner/lter assembly on the driver side of the
vehicle. The cap is marked TRANS FLUID.
SeeEngine Compartment Overview on page 5-12
for more information on location.
2. After removing the engine air cleaner/lter assembly
to reach the transmission uid cap, turn the cap
counterclockwise to remove. Pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Push it back in all the way, wait three seconds, and
then pull it back out again.4. Check both sides of the dipstick and read the
lower level. The uid level must be in the
cross-hatched area.
5. If the uid level is in the acceptable range, push
the dipstick back in all the way and turn the
handle clockwise.
6. Reinstall the engine air cleaner/lter assembly.
5-20

Cooling System
The cooling system allows the engine to maintain the correct working temperature.
A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fans4.6L L37 Engine shown, 4.6L LD8 Engine similar
5-22

{CAUTION:
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.
{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.Notice:Using coolant other than DEX-COOL
®can
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 vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in the
vehicle.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
The following explains the cooling system and how to
check and add coolant when it is low. If there is a
problem with engine overheating, seeEngine
Overheating on page 5-28.
5-23

What to Use
{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.Use a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant. If using this mixture, nothing else
needs 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, the
engine could overheat and be badly damaged. The
repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and other
parts.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 6-11for more information.
5-24

Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant recovery
tank. If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down. If
coolant is visible but the coolant level is not at or above
the FULL COLD mark, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant at the coolant
recovery tank, but be sure the cooling system is cool
before this is done. SeeEngine Coolant on page 5-23for
more information.
How to Add Coolant to the Surge Tank
{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.Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
{CAUTION:
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.
5-25

4. With the coolant surge tank cap off, start the
engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fans.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FULL COLD mark on the
side of the coolant surge tank.
5. Replace the cap. Be sure the cap is hand-tight and
fully seated.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.
If coolant is needed, add the proper DEX-COOL
®
coolant mixture at the coolant recovery tank.
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 5-12for more
information on location. 4.6L L37 Engine shown, 4.6L LD8 Engine similar
5-27

Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
There is an engine temperature warning light and/or
gage on the instrument panel cluster. SeeEngine
Coolant Temperature Warning Light on page 3-59and
Engine Coolant Temperature Gage on page 3-60.
The vehicle may also display a ENGINE OVERHEATED
IDLE ENGINE message or an ENGINE OVERHEATED
STOP ENGINE message displayed in the Driver
Information Center (DIC). SeeDIC Warnings and
Messages on page 3-73for more information. You will
also hear a chime.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Service on page 7-7.If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:If the engine catches re while driving with
no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by
the vehicle warranty. SeeOverheated Engine
Protection Operating Mode on page 5-30for
information on driving to a safe place in an
emergency.
5-28

If Steam Is Coming From The Engine
Compartment
{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 the engine if it
overheats, and get out of the vehicle until the
engine is cool.
SeeOverheated Engine Protection Operating Mode
on page 5-30for information on driving to a safe
place in an emergency.
If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no steam
can be seen or heard, the problem may not be too
serious. Sometimes the engine can get a little too hot
when the vehicle:
Climbs a long hill on a hot day.
Stops after high-speed driving.
Idles for long periods in traffic.
Tows a trailer.
If the overheat warning is displayed with no sign of
steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while
stopped. If it safe to do so, pull off the road, shift to
P (Park) or N (Neutral) and let the engine idle.
5-29