engine CADILLAC CTS 2006 1.G Repair Manual

Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you will go to your dealer
for all your service needs. You will get genuine GM parts
and GM-trained and supported service people.
We hope you will want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Accessories and Modications
When you add non-GM accessories to your vehicle
they can affect your vehicle’s performance and safety,
including such things as, airbags, braking, stability,
ride and handling, emissions systems, aerodynamics,
durability, and electronic systems like anti-lock brakes,
traction control and stability control. Some of these
accessories may even cause malfunction or damage
not covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your
GM dealer can accessorize your vehicle using genuine
GM Accessories. When you go to your GM dealer
and ask for GM Accessories, you will know that
GM-trained and supported service technicians will
perform the work using genuine GM Accessories.
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many uids, and
some component wear by-products contain and/or emit
these chemicals.
5-3

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your vehicle
can affect the airow around it. This may cause
wind noise and affect windshield washer performance.
Check with your dealer before adding equipment to
the outside of your vehicle.
Fuel
The 8th digit of your Vehicle Identication Number (VIN)
shows the code letter or number that identies your
engine. You will nd the VIN at the top left of the
instrument panel. SeeVehicle Identication Number
(VIN) on page 5-103.
Gasoline Octane
If your vehicle has the 2.8L V6 engine (VIN Code T),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you may notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking,
your engine needs service.
If your vehicle has the 3.6L V6 engine (VIN Code 7),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. For best performance or trailer
towing, you may choose to use middle grade 89 octane
unleaded gasoline. If the octane rating is less than
87, you may notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking, your
engine needs service.
5-5

If your vehicle has the 6.0L V8 engine (VIN Code U),
use premium unleaded gasoline with a posted
octane rating of 91 or higher. You may also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration may be slightly reduced,
and you may notice a slight audible knocking noise,
commonly referred to as spark knock. If the octane is
less than 87, you may notice a heavy knocking
noise when you drive. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
Otherwise, you might damage your engine. If you are
using gasoline rated at 87 octane or higher and you
hear heavy knocking, your engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
General Motors recommends against the use of
gasolines containing MMT. SeeAdditives on
page 5-6for additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that
meet California specications. See the underhood
emission control label. If this fuel is not available
in states adopting California emissions standards,
your vehicle will operate satisfactorily on fuels meeting
federal specications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may fail
a smog-check test. SeeMalfunction Indicator Lamp
on page 3-41. If this occurs, return to your authorized
GM dealer for diagnosis. If it is determined that the
condition is caused by the type of fuel used, repairs
may not be covered by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. In most cases, you should not have to add
anything to your fuel. However, some gasolines contain
only the minimum amount of additive required to
meet U.S. Environmental Protection Agency regulations.
5-6

Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re
can cause bad injuries. To help avoid injuries
to you and others, read and follow all the
instructions on the pump island. Turn off
your engine when you are refueling. Do not
smoke if you are near fuel or refueling your
vehicle. Keep sparks, ames, and smoking
materials away from fuel. Do not leave the
fuel pump unattended when refueling your
vehicle. This is against the law in some
places. Keep children away from the fuel
pump; never let children pump fuel.The tethered fuel cap is located behind a hinged fuel
door on the passenger’s side of the vehicle. To open
the fuel door, push inward on the forward edge of
the fuel door until the rear edge can be pulled outward.
To remove the fuel cap, turn it slowly counterclockwise.
The fuel cap has a spring in it; if the cap is released
too soon, it will spring back to the right.
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
5-8

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
Dispense gasoline only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping gasoline.
Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer
and other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

Engine Compartment Overview
When you open the hood on the 3.6L V6 engine (2.8L V6 engine similar), you will see the following:
5-12

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-105.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-37.
C. Battery. SeeBattery on page 5-41.
D. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-29.
E. Power Steering Fluid Reservoir (Under Engine
Cover). SeePower Steering Fluid on page 5-36.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-16.G. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-16.
H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
I. Hydraulic Clutch Reservoir (If Equipped)
(Not Shown). See “When to Check and What to
Use” underHydraulic Clutch on page 5-25.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 5-28andCooling System on page 5-31.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
5-13

A. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 5-105.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-37.
C. Battery. SeeBattery on page 5-41.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-16.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-29.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-16.G. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-36.
H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-38.
I. Hydraulic Clutch Reservoir. See “When to Check
and What to Use” underHydraulic Clutch on
page 5-25.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on
page 5-28andCooling System on page 5-31.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
5-15

Engine Oil
There is an oil pressure
light in the instrument
cluster and an Oil
Pressure Low - Stop
Engine message on
the Driver Information
Center (DIC).
If the light and/or message appear, it means you need
to check the engine oil level right away. For more
information, see “Oil Pressure Low - Stop Engine”
underDIC Warnings and Messages on page 3-61and
Oil Pressure Light on page 3-44. You should check
the engine oil level regularly; this is an added reminder.
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. See
Engine Compartment Overview on page 5-12for
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.
5-16

When to Add Engine OilIf the oil is below the cross-hatched area at the tip of the
dipstick, you will need to add at least one quart/liter of oil.
But you must use the right kind. This section explains
what kind of oil to use. For engine oil crankcase capacity,
seeCapacities and Specications on page 5-115.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
SeeEngine Compartment
Overview on page 5-12
for the location of the
engine oil ll cap.
Be sure to add enough oil to put the level somewhere
in the proper operating range. Push the dipstick all
the way back in when you are through. V6 Engines
V8 Engine
5-17