GMC 2001 Envoy - Manual (Page 422)

Long Trip/Highway Scheduled Maintenance
7-41
100,000 Miles (166 000 km)
j Inspect spark plug wires.
An Emission Control Service.
j Replace spark plugs.
An Emission Control Service.
j 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.
j Automatic Transfer Case Only: Change transfer case fluid.
j Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
j Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See “Engine Coolant” 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