spark plugs GMC ENVOY 2003 Owner's Manual

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. You should not have to add anything to your
fuel. Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines may be
available in your area to contribute to clean air.
General Motors recommends that you use these
gasolines, particularly if they comply with the
speci®cations described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Don't use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage wouldn't be covered under your
warranty.Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
5-6

Normal Maintenance Replacement Parts
Part Number
Engine Oil Filter
L6PF61*
V8PF44*
Engine Air CleanerA2014C*
Automatic Transmission Filter Kit GM Part No. 24200796
Spark Plugs
L641-981*
V841±974*
Fuel FilterGF831*
Windshield Wiper Blade 20.0 inches (50.8 cm)
Backglass Wiper Blade 14.0 inches (35.6 cm)
*ACDelco
žpart number
5-104

100,000 Miles (166 000 km)
qV8 Engine Only: Inspect spark plug wires.An
Emission Control Service.
qReplace spark plugs.An Emission Control Service.
qChange automatic transmission ¯uid and ®lter if
the vehicle is mainly driven under one or more
of these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
qIf you haven't used your vehicle under severe service
conditions listed previously and, therefore, haven't
changed your automatic transmission ¯uid, change
both the ¯uid and ®lter
qAutomatic Transfer Case Only: Change transfer case
¯uid.
qV8 Engine Only: Inspect Positive Crankcase
Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
qDrain, ¯ush and re®ll cooling system (or every
60 months since last service, whichever occurs ®rst).
See
Engine Coolant on page 5-24for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.
An Emission Control Service.
qInspect engine accessory drive belt.An Emission
Control Service.
6-10