Chevrolet 1980 Light Duty Truck Service Manual page 17

whichever occurs first.
• Change oil filter:
Light Duty Emissions-
change and then every second oil change if mileage 7,500
miles (12 000 km) determines oil change. If time (12
months) determines oil change, or you change the oil at
3,000 miles (4 800 km) or 3 months, replace filter at each
oil change.
Heavy Duty Emissions-
change, and then every second oil change if mileage 6,000
miles (9 600 km) determines oil change. If time (4 months)
determines oil change, or you change the oil at 3,000 miles
(4 800 km) or 2 months, replace filter at each oil change.
• Change oil and filter each 3,000 miles (4 800 km) or
3 months (light duty emissions) or 2 months (heavy duty
emission service) if:
• Driving in dusty areas
• Pulling a trailer
• Frequent idling or idling for long periods
• Driving 4 miles (6 km) or less in freezing weather,
or other short trips in cold weather, where the engine does
not thoroughly warm up.
• After driving in a dust storm, change the oil and filter
as soon as possible.
Engine Oil Additives
these extra engine oil helpers or additives if SE quality
engine oil is used and changed as suggested. If you think
your engine has an oil related problem, refer to Section 6A.
Diesel Engine
Use ONLY engine oils labeled with the A.P.I.
(American Petroleum Institute) designations SE and CC.
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 both the SE and the CC
designations, regardless of the order in which they appear
on the oil can. Do not use an oil if the designation CD
appears anywhere on the oil can. Using any type of oil other
than SE/CC may affect warranty.
Do NOT use engine oils labeled only SE or
NOTICE:
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 "SAE", which may also appear on the can.
• It is VERY IMPORTANT to change the oil and
filter every 3,000 miles (4 800 km). Because of the way a
diesel engine operates, contaminants build up in the oil
faster than in a gasoline engine which can cause engine wear
and/or damage.
• Change the oil and filter soon after driving in a dust
storm.
• Single viscosity grade oils (such as SAE 30) are more
satisfactory than multi-viscosity oils (such as SAE 10W-30)
for sustained high-speed driving.
The oil and filter change intervals for a diesel engine
are based on the use of SE/CC quality oils and quality oil
filters. Use of oils other than SE/CC or oil and filter change
Replace at the first oil
Replace at the first oil
The engine should not need
M A IN TEN A N C E AND LUBRICATION
NOTICE: Do not use SAE 5W-20 oils for continuous
high-speed driving.
Fig. OB-6--OM V isco sity C hart (Gasoline)
intervals longer than 3,000 miles (4 800 km) could reduce
engine life and may affect warranty.
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
additives. Using oil additives may cause engine damage and
may affect warranty. If you think the engine has an oil
related problem, see Section 6A.
Oil Viscosity (Figs. OB-6 and 7)
Engine oil viscosity (thicknesS^has an effect on fuel
economy. Lower viscosity engine oils can provide increased
fuel economy; however, higher temperature weather
conditions require higher viscosity engine oils for
satisfactory lubrication. Figures 0B-6 and 0B-7 lists the
engine oil viscosities that will provide the best balance of
fuel economy, engine life, and oil economy.
Checking Oil Level
The best time to check the engine oil level
• W arm -
is when the oil is warm, such as during a fuel stop. First,
allow about 5 minutes for the oil to drain back to the oil
pan. Then pull the dipstick out, wipe it clean, and push it
USE TH E S E SAE V IS C O S IT Y G R A D E S (SE/C C)
SAE 10W-30
«
0
F -20 20 32 40
+ -t—
C -30 -20 -10 0
* FO R S U S T A IN E D H IG H S P E E D D R IV IN G A B O V E
32°F (0°C) USE SA E 3 0 G R A D E .
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 IL C H A N G E
Fig. OB-7--OM V is co s ity Chart (Diesel)
OB-7
Do not use any supplemental
# i
r
S A E 30
60 80 100
10 20 30 40
LIG H T D U TY T R U C K SER V ICE M ANUAL