GMC 1982 Light Duty Truck Service Manual page 17

OB-8 MAINTENANCE AND LUBRICATION
U S E T H E S E S A E V IS C O S I T Y G R A D E S
I l
,.......
[| * M A Y B E U S E D U P T O 3 8 ° C IN 4 - C Y L I N D E R A N D 2 8 L V 6 E N G IN E S
pxaxbw ,100°F) |
* * D O N O T U S E F O R C O N T I N U O U S H IG H S P E E D D R I V I N G
OF - 2 0 0 2 0 3 2
°C - 3 0 - 2 0 - 1 0 0
T E M P E R A T U R E R A N G E Y O U E X P E C T B E F O R E N E X T O I L C H A N G E
Fig. OB-7--Oil Viscosity Chart (Gasoline)
• Do not use radiato r antifreeze in the windshield
washer; it could cause paint damage.
• In cold weather, warm the windshield with the defrosters
before using the washer—to help prevent icing that may
block the driver's vision.
Cooling System Care
Do not remove radiator cap to check coolant level.
Instead, check by looking at the "see through" coolant
recovery tank. Level should be at the "Full Cold" m ark on
the recovery tank when the system is cold; and at the "Full
H o t" m ark during engine operation. Add a 50/50 mixture
of a good quality ethylene glycol antifreeze and water to the
recovery tank when more coolant is needed. If frequent
additions are needed, cooling system.
NOTICE: If the proper quality antifreeze is used, there is
no need to add extra inhibitors or additives that claim
to improve the system. They may be harmful to the
proper operation of the system, and are an unnecessary
expense.
A -3 Engine Oil and Filter
Engine O il a n d Filter Recom m endations
Gasoline Engine
• Engine oils are labeled on the containers with various
API (American Petroleum Institute) designations of
quality.
• Use only S F quality engine oils (see m arkings on
containers).
• The oil and filter change intervals for the engine is
based on the use of SF-quality oils and high quality
filters. Using oils other than SF-quality oils, or oil
change intervals longer than listed, could reduce engine
life and might affect warranty.
• The engine was filled with an S F quality engine oil
when it was built. You do not have to change this oil
before the suggested
M aintenance Schedule folder for the oil change
intervals.
Always change oil and filter as soon as possible after
driving in a dust storm. Also, always use SF-Quality oils of
20W -20] '20W -40,'
1 OW - 3 0 1 ~ 1 6 W -4 0
I I I
4 0 6 0
8 0 1 0 0
10 3 0 4 0
2 0
1 0 0 8 5 3
change period. See your
the proper viscosity. See O w n e r's M anual for further
details.
Engine Oil Additives - The engine should not need these
extra engine oil helpers or additives if SF quality engine oil
is used and changed as suggested, it you think your engine
has an oil related problem, refer to Section 6A.
Diesel Engine
Use O N L Y engine oils labeled with the A.P.I.
(American Petroleum Institute) designation " S F / C D " or
" S F / C C " . Do not use any other type of oil. The A.P.I.
designations are listed somewhere on the oil can, usually on
the top or label. The A.P.I. has several designations, such as:
SC, SD, SE, CB, CC, CD.
Several different designations may appear on the can.
Be sure the oil used has either " S F / C D " or " S F / C C "
designations, regardless of the order in which they appear on
the oil can.
Using any type of oil other than " S F / C D " or " S F /
CC " may affect warranty.
NOTICE: Do N O T use engine oils labeled only SE or
only CC. These oils will not give the protection and
lubrication of diesel engine needs. When reading the
can, be sure not to confuse the SE designation with the
letters " SA E ", which may also appear on the can.
The diesel engine was filled with a quality engine oil
when it was built. You do not have to change the oil before
the recommended change interval. Keep in mind the engine
may use more oil when it is new. Check the oil level more
often when the engine is new.
Engine Oil Additives - Do not use any supplemental
additives. Using oil additives may cause engine dam age and
may affect warranty. If you think the engine has an oil
related problem, see Section 6A.
Oil Viscosity
Engine oil viscosity (thickness) has an effect on fuel
economy. Lower viscosity engine oils can provide increased
fuel economy; however, higher te m p e ra tu re w eather
conditions require higher
satisfactory lubrication. Figures OB-7 and OB-8 list the
engine oil viscosities that will provide the best balance of
fuel economy, engine life, and oil economy.
D I E S E L E N G I N E S U S E T H E S E S A E V I S C O S IT Y G R A D E S
I
s'
____________________s a 1 o w 30
OF -2 0
0 20 32
° c -3 0
-2 0 -1 0 0
T E M P E R A T U R E R A N G E Y O U E X P E C T B E F O R E N E X T O I L C H A N G E
Fig. OB-8—Oil Viscosity Chart (Diesel)
viscosity engine oils
'30
S A E p r e F E R R E D
I 1
S A E ' i 5W '■' 4 0
40 60 80 100
10 20
30
1 0 0 8 5 4
for
40