2001 GMC ENVOY cooling

Scheduled Maintenance
7-6
Short Trip/City Intervals
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection.
Every 100,000 Miles (166 000 km): Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km): Cooling System
Service (or every 60 months, whichever occurs first).
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
Long Trip/Highway Definition
Follow this scheduled maintenance only if none of
the conditions from the Short Trip/City Scheduled
Maintenance are true. Do not use this schedule if the
vehicle is used for trailer towing, driven in a dusty area
or used off paved roads. Use the Short Trip/City
schedule for these conditions.
Driving a vehicle with a fully warmed engine under
highway conditions causes engine oil to break
down slower.
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Scheduled Maintenance
7-7
Long Trip/Highway Intervals
Every 7,500 Miles (12 500 km): Engine Oil and Filter
Change (or every 12 months, whichever occurs first).
Chassis Lubrication (or every 12 months, whichever
occurs first). Drive Axle Service. Tire Rotation.
Every 15,000 Miles (25 000 km): Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Fuel Filter
Replacement. Engine Air Cleaner Filter Replacement.
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Automatic Transfer Case Only: Transfer Case
Fluid Change.
Long Trip/Highway Intervals
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection.
Every 100,000 Miles (166 000 km): Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km): Cooling System
Service (or every 60 months, whichever occurs first).
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
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Short Trip/City Scheduled Maintenance
7-29
100,000 Miles (166 000 km)

Inspect spark plug wires.
An Emission Control Service.

Replace spark plugs.
An Emission Control Service.

If you haven't used your vehicle under severe service conditions listed
previously and, therefore, haven't changed your automatic transmission
fluid, change both the fluid and filter. Manual transmission fluid doesn't
require change.

Automatic Transfer Case Only: Change transfer case fluid.

Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)

Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See ªEngine Coolantº in the Index for what to use.
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
cooling system and pressure cap.
An Emission Control Service.
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE
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Long Trip/Highway Scheduled Maintenance
7-41
100,000 Miles (166 000 km)

Inspect spark plug wires.
An Emission Control Service.

Replace spark plugs.
An Emission Control Service.

If you haven't used your vehicle under severe service conditions listed
previously and, therefore, haven't changed your automatic transmission
fluid, change both the fluid and filter. Manual transmission fluid doesn't
require change.

Automatic Transfer Case Only: Change transfer case fluid.

Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)

Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See ªEngine Coolantº in the Index for what to use.
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
the cooling system and pressure cap.
An Emission Control Service.
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE
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7-48 Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of the
cooling system and pressure cap is recommended at
least once a year.
Throttle System Inspection
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts as
needed. Replace any components that have high effort
or excessive wear. Do not lubricate accelerator and
cruise control cables.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. A fluid loss could indicate a problem;
check and have it repaired, if needed. Check vent hose
at transfer case for kinks and proper installation. More
frequent lubrication may be required on off
-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and
rotors for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. Check parking
brake adjustment. You may need to have your brakes
inspected more often if your driving habits or conditions
result in frequent braking.
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