010601011L

Bulletin No.:
Service Bulletin
Date:
01-06-01-011L
December, 2020
INFORMATION
Subject:
Information on Engine Oil Consumption Guidelines
Models:
2021 and Prior GM Passenger Cars and Gasoline-Powered Light Duty Trucks Under
8500 LB GVW
Attention: This bulletin also applies to any of the above models that may be Exported to or sold
in: North America, Europe, Uzbekistan, Russia, Middle East, Iraq, Israel, Palestine,
Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay,
Venezuela, Japan, Cadillac Korea (South Korea), GM Korea Company, China, Taiwan,
Thailand, Singapore, Philippines, Egypt, Other Africa, South Africa
This bulletin has been revised to add the 2021 Model Year, update the Attention statement
and add How To Identify If A Vehicle Idles More Than An Average Vehicle section. Please
discard Corporate Bulletin Number 01-06-01-011K.
All engines require oil to lubricate and protect the load
bearing and internal moving parts from wear including
cylinder walls, pistons and piston rings. When a piston
moves down its cylinder, a thin film of oil is left on the
cylinder wall. During the power stroke, part of this oil
layer is consumed in the combustion process. As a
result, varying rates of oil consumption are accepted as
normal in all engines.
Oil Consumption
The accepted rate of oil consumption for engines used
in the vehicles referenced is 0.946 liter (1 qt) in 3200 km
(2000 mi).
Important: This rate only applies to personal use
vehicles, under warranty, that are driven in a
non-aggressive manner and maintained in accordance
with the appropriate maintenance schedule, with less
than 58,000 km (36,000 mi), or driven at legal speeds in
an unloaded (for trucks) condition.
Important: This rate does not apply to vehicles that
are driven in an aggressive manner, at high RPM, high
speeds, or in a loaded condition (for trucks). Oil
consumption for vehicles driven under these conditions
will be more.
Many factors can affect a customer's concern with oil
consumption. Driving habits and vehicle maintenance
vary from owner to owner. Thoroughly evaluate each
case before deciding whether the vehicle in question
has abnormal engine oil consumption.
Gasket and External Leaks
Inspect the oil pan and engine covers for leakage due
to over-tightened, damaged, or out of place gaskets.
Inspect oil lines and fittings for signs of leakage.
Copyright 2020 General Motors LLC. All Rights Reserved.
How To Identify If A Vehicle Idles More Than An
Average Vehicle
Note: Use this formula as a diagnostic aid and in the
administration of a maintenance schedule. It should
NOT be used to determine warranty coverage.
Some vehicles may spend a lot of time idling. Use the
formula to aid in determining the equivalent mileage
(kilometers):
• Check and record the total engine hours on the
Driver Information Center (DIC). You may need to
go into the settings menu on the DIC to display the
engine hours.
• Multiply this time by 33 miles or 53 km. This
represents an average speed of 54 km/h
(33 mph).
• The result should be close to or lower than the
mileage on the odometer.
• Example 1: If a vehicle has 1812.3 engine
hours and 60,837 miles (97,908 km) on the
odometer, the engine run time would equate to
about 59,806 miles (96,052 km) (1812.3 X 33 =
59,806) (1812.3 X 53 = 96,052)).
Because the calculated mileage is less than
the actual mileage, this vehicle does not spend
an excessive amount of time idling.
• Example 2: If the vehicle has 626.9 engine
hours and 7,269 miles (11,698 km) on the
odometer, the engine run time would equate to
about 20,688 miles (33,226 km) (626.9 X 33 =
20,688 (626.9 X 53 = 33,226)).
Page 2
December, 2020
Because the calculated mileage is more than
the actual mileage, this vehicle would be
considered a vehicle that idles a lot and this
information may be useful in diagnosing any
issues.
Improper Reading of the Oil Level Indicator
(Dipstick)
Verify that the dipstick tube is fully seated in the block.
When checking the oil level, make sure the dipstick is
wiped clean before taking an oil level reading and fully
depress the dipstick until the shoulder bottoms out on
the dipstick tube. The dipstick should be the proper part
number for the engine/vehicle that is being checked.
Notice: Operating your vehicle with an oil level that is
below the minimum level indicated on the engine oil
dipstick can result in severe engine damage. Repairs
resulting from operating an engine with insufficient oil
are not covered under the terms of the New Vehicle
Warranty.
Important: Refer to Owner Manual in SI for checking
and adding engine oil.
Not Waiting Long Enough After Running Engine to
Check Oil Level
Some engines require more time than others for the oil
to drain back into the crankcase. To assure a sufficient
amount of oil has drained back to the crankcase, and
an accurate reading can be obtained, the vehicle
should be allowed to sit for at least 15 minutes, after the
engine has been shut off, before taking an oil level
reading. In order to ensure accurate results, the
temperature of the oil should be close to the same
temperature as the last time the oil level was checked.
Important: This does not apply to 2006-2009 Corvette
Z06 equipped with the 7.0L LS7 and the 2009 Corvette
ZR-1 with the 6.2L LS9 engines (dry sump). Follow the
instructions in the Owner Manual for checking the oil in
this application.
Improper Oil Fill After an Oil Change
Following an oil change, verify that the proper amount
and type of oil was put in the engine and that the oil
level on the dipstick is not above the full mark or below
the add marks. Refer to the Owner Manual or Service
Manual for information on recommended oil quantity,
viscosity, and quality.
Aggressive Driving, High Speed or High RPM
Driving
Aggressive driving and/or continuous driving at high
speeds/high RPMs will increase oil consumption.
Because this may not always be an everyday
occurrence, it is hard to determine exactly how much
the oil economy will be affected.
A higher rate of oil consumption is normal for vehicles
equipped with manual transmissions that are driven
aggressively. By “aggressive,” we mean operation at
high RPM (3,000 RPM to redline), with frequent use of
engine braking (using the engine to slow the vehicle).
Vehicles that are driven aggressively may consume
engine oil at a rate of up to 0.946 L (1 quart) every
805 km (500 mi). This is normal for a vehicle that is
driven aggressively. No repair is necessary. This
Bulletin No.: 01-06-01-011L
characteristic does, however, require the owner to
check the engine oil level at sufficiently frequent
intervals, especially when driving aggressively, to
assure the oil level remains within the recommended
operating range. As the Owner Manual recommends,
you should check the oil level every time you get fuel.
Towing or Heavy Usage
Towing a trailer will increase oil consumption and may
cause oil consumption to fall below the normal
accepted rate referenced in this bulletin for an
unloaded vehicle in a personal use application. Large
frontal area trailers will further increase the work
required from the engine, especially at highway
speeds, and thus increases the rate of oil consumption.
Crankcase Ventilation System
Verify that the positive crankcase ventilation (PCV)
system is operating properly. Blockages, restrictions, or
damage to the PCV system can result in increased
oil use.
Oil Dilution (Fuel and Water)
On vehicles that are usually driven short distances, less
than 8 km (5 mi), especially in colder weather, unburned
fuel and condensation generated from cold engine
operation may not get hot enough to evaporate out of
the oil. When this occurs, the dipstick may indicate that
the oil level is over-full. Subsequent driving on a trip of
sufficient length to enable normal engine operating
temperature for 30 minutes or more, in order to
vaporize excess moisture and fuel, may give the
customer the impression of excessive oil consumption.
Engine Temperature
If an engine is run at overheated temperatures (see
Owner's Manual or Service Manual) for more than brief
periods, oil will oxidize at a faster than normal rate. In
addition, gaskets may distort, piston rings may stick,
and excessive wear may result. Verify that all cooling
system components are in proper working order.
Engine Wear
Piston scuffing, excessive piston-to-wall clearance,
tapered or out of round cylinders, worn, damaged or
improperly installed valve guides, seals and piston
rings will all cause an increase in oil consumption.
Measurement of Oil Consumption
Engines require a period of time to BREAK IN so that
moving parts are properly seated. Therefore, oil
economy should not be tested until the vehicle has
accumulated at least 6400 km (4000 mi). An exception
would be allowed only if an engine is reported to be
using more than 0.946 liter (1 qt) in 1600 km (1000 mi).
1. Verify that the engine has no external leaks. Repair
as necessary.
2. Verify that the engine is at normal operating
temperature (see Owner Manual or Service
Manual).
3. Park the vehicle on a level surface.
4. Wait at least 15 minutes, after the engine is shut
off, before checking the oil level to make sure that
the oil has had time to drain back into the
crankcase.
Bulletin No.: 01-06-01-011L
December, 2020
Page 3
5. Verify that the oil level is at, but not above, the full
mark on the dipstick, and that the proper viscosity
and quality oil are being used as recommended in
the Owner Manual.
6. Record the vehicle mileage, date, and exact oil
level on the form included in this bulletin.
7. Ask the customer to verify the oil level, each time
the vehicle is fueled, following steps 1–6 and return
the vehicle to the dealership if the oil level is found
at or below the add mark, 0.946 liter (1 qt) low. If
the oil level remains above the add mark, the
customer should continue to operate the vehicle
and verify the engine oil level until 3200 km
(2000 mi) has accumulated before returning to the
dealership for a final evaluation.
8. If the final evaluation shows that the engine uses
more than 0.946 liter (1 qt) in 3200 km (2000 mi),
follow the published symptom diagnostics as
described in the appropriate Service Manual. If the
oil consumption test shows that the engine uses
less than 0.946 liter (1 qt) in 3200 km (2000 mi),
explain to the customer that their engine meets the
guidelines for oil consumption.
Oil Economy Test — Data Sheet
Dealer
Name: _________________________________
Customer
Name: _________________________________
Phone: (___)____-_______ Phone:
(___)____-_______
VIN: ____________________________
Oil Type Used: ____________________
R.O. #: ___________________
Step
Date
Mileage
Oil Level
Driving Conditions
(City, Highway, Both)
1
(Start of Test)
2
3
4
5
6
7
8
9
10
11
12
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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