2007 GMC ENVOY DENALI coolant

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or a lower gear,
under heavy loads or hilly conditions.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant will
boil at a lower temperature than at normal
altitudes. If you turn your engine off immediately
after towing at high altitude on steep uphill grades,
your vehicle may show signs similar to engine
overheating. To avoid this, let the engine run while
parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few
minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating
on page 408.
372

Service........................................................ 380
Accessories and Modications................... 380
California Proposition 65 Warning.............. 381
Doing Your Own Service Work.................. 381
Adding Equipment to the Outside of
Your Vehicle.......................................... 382
Fuel............................................................. 382
Gasoline Octane........................................ 382
Gasoline Specications.............................. 383
California Fuel........................................... 383
Additives................................................... 383
Fuels in Foreign Countries........................ 384
Filling the Tank......................................... 385
Filling a Portable Fuel Container............... 387
Checking Things Under the Hood.............. 388
Hood Release........................................... 388
Engine Compartment Overview.................. 390
Engine Oil................................................. 394
Engine Oil Life System.............................. 398
Engine Air Cleaner/Filter............................ 400
Automatic Transmission Fluid.................... 401
Engine Coolant.......................................... 405Radiator Pressure Cap.............................. 408
Engine Overheating................................... 408
Cooling System......................................... 411
Engine Fan Noise..................................... 416
Power Steering Fluid ................................. 417
Windshield Washer Fluid........................... 418
Brakes...................................................... 419
Battery...................................................... 422
Jump Starting............................................ 423
Rear Axle.................................................... 428
Four-Wheel Drive........................................ 428
Front Axle................................................... 429
Bulb Replacement....................................... 430
Halogen Bulbs........................................... 430
Headlamps................................................ 431
Front Turn Signal, Sidemarker and
Parking Lamps....................................... 432
Taillamps, Turn Signal, and Stoplamps...... 432
Back-Up Lamps......................................... 434
License Plate Lamp................................... 435
Replacement Bulbs................................... 435
Section 5 Service and Appearance Care
377

Checking Things Under
the Hood
{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.
Hood Release
1. To open the hood,
rst pull the handle
with this symbol
on it. It is located
inside the vehicle
under the instrument
panel on the
driver’s side.
388

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 400.
B. Engine Coolant Recovery Tank. SeeCooling
System on page 411.
C. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 418.
D. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 417.
E. Automatic Transmission Fluid Dipstick (Out of
View). See “Checking the Fluid Level” under
Automatic Transmission Fluid on page 401.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 394.G. Radiator Pressure Cap. SeeRadiator Pressure
Cap on page 408.
H. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 394.
I. Remote Negative (−) Terminal (Marked GND).
SeeJump Starting on page 423.
J. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 419.
K. Battery. SeeBattery on page 422.
L. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 493.
391

A. Engine Coolant Recovery Tank. SeeCooling
System on page 411.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 400.
C. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 418.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 394.
E. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 401.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 394.G. Radiator Pressure Cap. SeeRadiator Pressure
Cap on page 408.
H. Remote Negative (−) Terminal (Marked GND).
SeeJump Starting on page 423.
I. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 417.
J. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 419.
K. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 493.
L. Battery. SeeBattery on page 422.
393

Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 517.
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.
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 408.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give 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.
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.
405

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant. 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. 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 four 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.
SeeRecommended Fluids and Lubricants
on page 517for more information.
406

Checking Coolant
The engine coolant
recovery tank is in the
engine compartment on
the passenger’s side of
the vehicle. The cap has
this symbol on it. See
Engine Compartment
Overview on page 390
for more information on
location.
The vehicle must be on a level surface. When
your engine is cold, the coolant level should be
at FULL COLD, or a little higher.
Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the coolant
recovery tank.
{CAUTION:
Turning the radiator pressure cap when
the engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. With the coolant
recovery tank, you will almost never have
to add coolant at the radiator. Never turn
the radiator pressure cap — even a
little — when the engine and radiator
are hot.
407