2007 CADILLAC DTS cooling

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 452.
B. Remote Positive (+) Terminal. SeeJump
Starting on page 392.
C. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 386.
D. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 377andCooling System on page 380.
E. Remote Negative (−) Terminal. SeeJump
Starting on page 392Jump Starting.
F. Power Steering Fluid. SeePower Steering
Fluid on page 385.
G. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 365.
H. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 365.
I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 387.
J. Automatic Transaxle Fluid Cap and Dipstick
(Out of View). SeeAutomatic Transaxle
Fluid on page 372.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 370.Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 364
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
365

How to Add Automatic Transaxle Fluid
Refer to the Maintenance Schedule to determine
what kind of transaxle uid to use. See
Recommended Fluids and Lubricants on page 475.
If the uid level is low, add only enough of the
proper uid to bring the level into the
cross-hatched area on the dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at
the dipstick hole to bring it to the proper level.
It does not take much uid, generally less
than one pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic
transaxle uid may damage your vehicle, and
the damages may not be covered by your
warranty. Always use the automatic transaxle
uid listed inRecommended Fluids and
Lubricants on page 475.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transaxle Fluid,” earlier in this section.
4. When the correct uid level is obtained, push
the dipstick back in all the way and turn the
handle clockwise.
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 377.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Giving 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.
374

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.
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.
CAUTION: (Continued)
CAUTION: (Continued)
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 two times 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 475for more information.
375

Cooling System
When you decide it is safe to lift the hood, here is what you will see:
A. Coolant Surge Tank with Pressure Cap B. Electric Engine Cooling Fans
4.6L L37 Engine shown, 4.6L LD8 Engine similar
380

{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.
{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. SeeOverheated Engine Protection
Operating Mode on page 379for 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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
381

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 level is not at the FULL COLD
mark located on the side of the surge tank,
add enough of a 50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant at the coolant
surge tank to bring the level to the FULL COLD
mark, but be sure the cooling system, including the
coolant surge tank pressure cap, is cool before
you do it. SeeEngine Coolant on page 374
for more information.If no coolant is visible in the surge tank, add
coolant as follows:
{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.
382

{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.
{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.
1. You can remove the
coolant surge tank
pressure cap when
the cooling system,
including the coolant
surge tank pressure
cap and upper
radiator hose, is no
longer hot.
Turn the pressure cap slowly counterclockwise.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
2. Then keep turning the cap and remove it.
383

3. Fill the coolant
surge tank with the
proper mixture
to the FULL COLD
mark on the
side of the coolant
surge tank.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. Then replace the cap. Be sure the cap is
hand-tight and fully seated.
4.6L L37 Engine shown, 4.6L LD8 Engine similar
384