Information On Engine Oil Consumption Guidelines – 3.0L Duramax Diesel – 2020-2022 Cadillac Chevrolet GMC

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Service Bulletin Bulletin No.: 21-NA-272
Date: November, 2021
INFORMATION
Subject: Information On Engine Oil Consumption Guidelines
This Bulletin replaces PIP5751. Please discard PIP5751.
Brand: Model:
Model Year: VIN:
Engine:
Transmission:
from to from to
Cadillac Escalade Models 2021
2022 – –
Equipped
with 3.0L
(RPO LM2)
–
Chevrolet
Silverado 1500 2020
Suburban
2021
Tahoe
GMC
Sierra 1500 2020
Yukon Models 2021
Involved Region or Country North America
Information on Engine Oil Consumption
Guidelines for the 3.0L Duramax Diesel
Engine
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 combustion process, part of
this oil layer is consumed. 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 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 and accepted rate is 0.946 liter (1qt) in
1600 km (1000mi).
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 pans, engine covers, and the engine oil
cooler for leakage. Inspect the turbocharger oil lines
and fittings for signs of leakage. Inspect the
turbocharger outlet pipe for signs of oil, indicating worn
turbocharger shaft bushings or seals. Inspect for oil
leakage into the engine coolant.
Improper Reading of the Oil Level
Indicator (Dipstick)
The vehicle must be parked on a level surface to obtain
accurate oil level readings. 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.
Page 2 November, 2021 Bulletin No.: 21-NA-272
Not Waiting Long Enough After
Running Engine to Check Oil Level
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 to assure the oil has had
enough time to drain back into the crankcase. 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.
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’s Manual or Service
Manual for information on recommended oil quantity,
viscosity, and quality.
Aggressive Driving, High Speed/High
RPM or Towing/Heavy Usage
Aggressive driving and/or continuous driving at high
speed/high RPM and/or Towing/Heavy usage will
increase oil consumption. Vehicles that are driven
under these conditions may consume engine oil at a
rate up to 0.946 liter (1 quart) every 1600km
(1000miles). This is normal and no repair is required.
This characteristic does, however, requires the owner
to check the engine oil level at a sufficiently frequent
intervals, to assure the oil level remains within the
recommended operating range.
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 from Condensation
On vehicles that are usually driven short distances, less
than 8 km (5 mi), especially in colder weather,
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, 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 8000 km (5000 mi) and the oil has
been changed for the first time. An exception would be
allowed only if an engine is reported to be using more
than 0.946 liter (1qt) in 1600 km (1000mi).
Verify that the engine has no external leaks. Repair as
necessary.
1. Begin oil consumption test after next regularly
scheduled oil and filter change. It is critical to make
sure that the new oil filter is tightened 1 to 1-1/4
turn after contact. Refer to Engine Oil and Oil Filter
Replacement in SI. Oil changes should not be
performed during the test.
2. Verify that the engine is at normal operating
temperature (see Owner’s 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
most of the oil has had time to drain back into the
crankcase.
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’s Manual.
6. Dealer should record the vehicle mileage, date and
engine hours at the start of the test on the form
included in this bulletin.
7. Ask the customer to verify and record the date,
odometer, oil level, fuel added, engine hours,
percentage of driving done in aggressive manner
or at high speed/high RPM or with a trailer and
trailer weight, each time the vehicle is fueled,
following steps 3-5 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 possible. The
dealer will add oil to return the oil level to full. If the
oil level remains above the add mark, the customer
should continue to operate the vehicle and verify
the engine oil level until either the oil level drops to
or below the add mark or at least 4800 km (3000
mi) has accumulated since the test began before
returning to the dealership for a final evaluation.
8. Refer to Oil Consumption section to compare the
final evaluation to the proper acceptable oil
consumption. Explain to the customer that their
engine meets the guidelines for oil consumption if it
falls into the acceptable range.
Oil Consumption Worksheet
Owner Name Location
Dealer Name Dealer Code
Assign TAC TAC Case #
Engine Model Serial #
VIN Oil Brand
Oil Viscosity Fuel Brand
Bulletin No.: 21-NA-272 November, 2021 Page 3
– Date Odometer Reading Engine Hours Fuel Quantity
Added Oil Quantity Added
Start
Version 1
Modified Released November 19, 2021

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