2009 GMC ENVOY engine

{CAUTION:
Operating the engine with the air cleaner/lter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there and
the engine backres, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can easily get
into the engine, which will damage it. Always have
the air cleaner/lter in place when you are driving.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check the automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-12.
5-21

How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage your
transmission. Too much can mean that some of the
uid could come out and fall on hot engine parts or
exhaust system parts, starting a re. Too little uid
could cause the transmission to overheat. Be sure
to get an accurate reading if you check your
transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
drive the vehicle in 3 (Third) until the engine temperature
gage moves and then remains steady for 10 minutes.
A cold uid check can be made after the vehicle has been
sitting for eight hours or more with the engine off, but this
is used only as a reference. Let the engine run at idle for
ve minutes if outside temperatures are 50°F (10°C) or
more. If it is colder than 50°F (10°C), you may have to
idle the engine longer. Should the uid level be low during
this cold check, you must check the uid hot before
adding uid. Checking the uid hot will give a more
accurate reading of the uid level.
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 minutes or more.
5-22

Then, without shutting off the engine, follow these steps:
1. Flip the handle up and then remove the dipstick
and wipe it with a clean rag or paper towel.
The automatic
transmission dipstick
handle with this symbol on
it is located in the engine
compartment on the
passenger side of the
vehicle.
SeeEngine Compartment Overview on page 5-12
for more information on location.
2. Reinstall it back in all the way, wait three seconds
and then pull it back out again. If the dipstick does
not go down the tube easily, turn the blade and
try again until it is fully inserted in the tube.3. Check both sides of the dipstick and read the lower
level. The uid level must be in the COLD area,
below the cross-hatched area, for a cold check or
in the HOT or cross-hatched area for a hot check.
Be sure to keep the dipstick pointed down to get an
accurate reading.
4. If the uid level is in the acceptable range, reinstall
the dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
5-23

Consistency of Readings
Always check the uid level at least twice using the
procedure described previously. Consistency (repeatable
readings) is important to maintaining proper uid level. If
inconsistent readings persist, contact your dealer/retailer.
How to Add Automatic Transmission
Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-12.
Add uid only after checking the transmission uid while
it is hot. A cold check is used only as a reference. If the
uid level is low, add only enough of the proper uid to
bring the level up to the HOT area for a hot check. It does
not take much uid, generally less than one pint (0.5 L).
Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages may
not be covered by the vehicle’s warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
After adding uid, recheck the uid level as described
under “How to Check Automatic Transmission Fluid”
earlier in this section.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle down
to lock the dipstick in place.
Cooling System
The cooling system allows the engine to maintain the
correct working temperature.
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan5.3L V8 Engine shown, 4.2L L6 Engine similar
5-24

{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®. 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 5-30.
5-25

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 6-12for more information.
5-26

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.
The coolant level should be at least up to the FULL
COLD mark. If it is not, there may be a leak in the
cooling system.
How to Add Coolant to the
Recovery 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.
If coolant is needed, add the proper DEX-COOL coolant
mixture at the coolant recovery tank.
When the coolant in the coolant recovery tank is at the
FULL COLD mark, start the vehicle.
5-27

How to Add Coolant to the Radiator
{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:
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 coolant is needed, add the proper mixture directly to
the radiator, but be sure the cooling system is cool
before this is done.
1. You can remove the radiator pressure cap when the
cooling system, including the radiator pressure cap
and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise about
one full turn. If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure left.
2. Then keep turning the pressure cap. Remove the
pressure cap.
5-28