NHTSA ID Number: 10205594
Manufacturer Communication Number: 21NA278
Summary
This service bulletin provides diagnostic strategy information to aid in diagnosing a Ticking, Tap or Rattle Noise from Engine with Possible Misfire, Malfunction Indicator Lamp (MIL) Illuminated.
57 Affected Products
Vehicles
| MAKE | MODEL | YEAR |
BUICK | LACROSSE | 2017-2019 |
| BUICK | REGAL | 2018-2020 |
| CADILLAC | ATS | 2016-2019 |
| CADILLAC | CT5 | 2020-2022 |
| CADILLAC | CT6 | 2016-2020 |
| CADILLAC | CTS | 2016-2019 |
| CADILLAC | XT5 | 2017-2019, 2021-2022 |
| CADILLAC | XT6 | 2020-2022 |
| CHEVROLET | BLAZER | 2019-2021 |
| CHEVROLET | CAMARO | 2016-2022 |
| CHEVROLET | COLORADO | 2017-2022 |
| GMC | ACADIA | 2017-2019, 2021-2022 |
| GMC | CANYON | 2017-2022 |
Condition
Some customers may comment that the vehicle has a rattle, tick, or knock type noise.
Some customers may also state that the MIL may have been illuminated.
– This noise and/or MIL light may also be accompanied by DTC P0300 (Engine Misfire Detected) and/or a specific cylinder misfire DTC such as P0300, P0301-P0306 or possible camshaft correlation codes P0016-P0019.
Note: Please take a sound file or video with sound of any noise prior to any disassembly. If this step is skipped, you may be asked to reassemble the engine prior to being helped with determining if the engine needs to be replaced. See the latest version of PIP5358 – Vehicle Noise Diagnosis and TAC Requests for Assistance with Noise Related Complaints for instruction on using the PICO for this.
This sound file may be needed when contacting GM Technical Assistance Center (TAC) or if needed further review with engineering. This noise could be all the time, only under load, or intermittent depending on the severity of the noise. You may find this noise hard to isolate to one area in the engine. After you have recorded a sound file of the noise, try to isolate the noise to a general area of the engine. At that point following the steps in this bulletin in order may help pinpoint the concern.
The concern may be more noticeable on the Active Fuel management System (AFM) cylinders.
Cause
This condition may be caused by spongy Stationary Hydraulic Lash Adjusters (SHLAs) or damaged Switching Roller Finger Followers (SRFF), damaged camshaft actuator or camshaft locating slots or a left bank timing chain tensioner gasket not sealing. The condition could be all the time, only under load, intermittent, or when first started after a hot soak depending on the cause.
Correction
If any of the conditions listed above have been verified, refer to the Service Procedure below.
SEOCONTENT-START
Service Bulletin Bulletin No.: 21-NA-278
Date: November, 2021
INFORMATION
Subject: Diagnostic Strategy for Ticking, Tap or Rattle Noise from Engine with Possible Misfire,
Malfunction Indicator Lamp (MIL) Illuminated – DTCs P0300, P0301-P0306 and/or
P0016-P0019 Set
This bulletin replaces PIP5486H and PIP5493J. Please discard PIP5486H and PIP5493J.
Brand: Model:
Model Year: VIN: Engine:
(3.0L, 3.6L)
Transmission:
from to from to
Buick
LaCrosse 2017 2019
— —
LGX
—
Regal 2018 2020 LGX
Cadillac
ATS 2016 2019 LGX
CT5 2020 2022 LGY
CT6 2016 2020 LGW, LGX
CTS 2016 2019 LGX
XT5 2017 2022 LGX
XT6 2020 2022 LGX
Chevrolet
Blazer 2018 2021 LGX
Camaro 2016 2022 LGX
Colorado 2017 2022 LGZ
GMC
Acadia
2017 2022
LGX
Canyon LGZ
Holden
Acadia 2019 2020
LGX
Commodore 2018 2020
Involved Region or Country
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, Australia/New Zealand, Egypt, Other Africa, South
Africa
Page 2 November, 2021 Bulletin No.: 21-NA-278
Condition
Some customers may comment that the vehicle has a rattle, tick, or knock type noise.
Some customers may also state that the MIL may have been illuminated.
– This noise and/or MIL light may also be accompanied by DTC P0300 (Engine Misfire
Detected) and/or a specific cylinder misfire DTC such as P0300, P0301-P0306 or
possible camshaft correlation codes P0016-P0019.
Note: Please take a sound file or video with sound of any noise prior to any disassembly.
If this step is skipped, you may be asked to reassemble the engine prior to being helped
with determining if the engine needs to be replaced. See the latest version of PIP5358 –
Vehicle Noise Diagnosis and TAC Requests for Assistance with Noise Related
Complaints for instruction on using the PICO for this.
This sound file may be needed when contacting GM Technical Assistance Center (TAC)
or if needed further review with engineering. This noise could be all the time, only under
load, or intermittent depending on the severity of the noise. You may find this noise hard
to isolate to one area in the engine. After you have recorded a sound file of the noise, try
to isolate the noise to a general area of the engine. At that point following the steps in this
bulletin in order may help pinpoint the concern.
The concern may be more noticeable on the Active Fuel management System (AFM)
cylinders.
Cause
This condition may be caused by spongy Stationary Hydraulic Lash Adjusters (SHLAs) or
damaged Switching Roller Finger Followers (SRFF), damaged camshaft actuator or
camshaft locating slots or a left bank timing chain tensioner gasket not sealing. The
condition could be all the time, only under load, intermittent, or when first started after a
hot soak depending on the cause.
Correction If any of the conditions listed above have been verified, refer to the Service Procedure
below.
Service Procedure
1. Perform injector diagnosis to ensure there are no
leaking injectors causing a noise due to excessive
fuel in one cylinder:
• Perform GDS2 or AFIT test on injectors to
isolate a leaking injector.
• Replace any out of specification injectors.
• Re-evaluate the noise.
2. Perform cylinder cancellation for each cylinder.
This may help pinpoint the source of a rattle noise.
3. Perform normal SI diagnostics testing all spark and
fuel components for issues. Coil grounds and
wiring, injector concerns, spark plugs, etc.
4. Remove the intake manifold and visually inspect
for excessive carbon on the intake valve stems and
top of the valve causing noise.
• If carbon is present, then follow Service Bulletin
# 16-NA-383 to clean the valves or replace
heads as needed.
• Re-evaluate the noise concern.
5. Remove the cam cover of the affected bank or both
if unable to isolate to inspect for soft, spongy, or
damaged SHLAs or rockers on all cylinders.
5924232
⇒ Push down on the rocker end at the SHLA to
test for soft or spongy feel.
Bulletin No.: 21-NA-278 November, 2021 Page 3
5924230
⇒ Check for any visible damage to non-AFM
rocker clips.
5924231
Note: If all SHLAs (lifters) are hard and no damage to
rockers is visible, proceed to step 6.
6. If the replacement SHLAs are still spongy, it will be
necessary to remove the affected head and inspect
the head gasket for debris in the oil passages as
indicated in the graphic above.
⇒ If debris is found, inspect the camshaft caps for
wear or discoloration due to lack of oil.
⇒ If wear or discoloration is found, then replace
the cylinder head assembly with camshafts.
⇒ If there is no wear or discoloration, clean the oil
passages and replace the head gasket.
⇒ Change the oil and filter.
⇒ Reevaluate the noise concern.
7. Without starting the engine, crank engine over and
ensure that the valves are opening and closing.
– If they are not operating correctly, it will be
necessary to inspect the SRFFs for any damage.
8. Inspect the SRFFs and rocker assemblies for any
damage or dislodge.
⇒ While inspecting the rockers, it will be
necessary to rotate the engine over by hand to
ensure that the rockers are opening the valves.
Note: Camshaft carrier assembly removal will be
necessary to fully inspect the rockers and SRFFs.
⇒ Below are pictures of possible SRFF failures. If
any one of the SRFFs are damaged, it will be
necessary to replace all four on the affected
cylinder.
5924236
⇒ Broken Torsion Spring
5924237
⇒ Broken or Worn Pin Shelf
Page 4 November, 2021 Bulletin No.: 21-NA-278
5924233
⇒ Stuck Locking Pin
For any of the above conditions, engine
replacement is not necessary. Please perform
the repair for the particular issue found.
5924235
9. Remove the camshaft actuators on the bank that is
misfiring and inspect the end of the camshafts and
the pin in the actuators for being bent.
⇒ If any broken parts are found during inspection,
replace all damaged parts.
5924234
10. Inspect the left bank timing chain tensioner gasket
for not sealing correctly.
⇒ Replace the tensioner and gasket if this
condition is found.
11. If noise condition is still present, proceed to
step 12.
12. Raise the vehicle while running or with an assistant
inside.
• With chassis ears or a stethoscope, listen to the
right and left side of the engine.
• Once the noise is isolated or if unable to isolate,
remove the piston and rod assemblies from the
affected bank(s) to inspect for either a loose rod
bushing in the rod or a loose wrist pin in the
bushing.
• There should be no metal in the oil for this
condition.
• If this is found, a piston and rod assembly will
repair this noise.
Once all the above inspections and/or diagnostics are
completed, if nothing is found to be the cause for the
noise, engine replacement MAY be necessary.
Version 1
Modified Released November 23, 2021
SEOCONTENT-END
1 Associated Document
Manufacturer Communications
Bulletin No.: 21-NA-278
Date: November, 2021
MC-10205594-9999.pdf 202.373KB
NHTSA ID Number: 10144455
Manufacturer Communication Number: PIP5493G
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017. Changes to Preliminary information include adding MY2018, advising of calibration for previous investigation and adding pictures to identify concern. Also defining calibration update information.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493G
Published date: 08/9/2018
MC-10144455-9999.pdf 516.989KB
NHTSA ID Number: 10137181
Manufacturer Communication Number: PIP5493F
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017. Changes to Preliminary information include adding MY2018, advising of calibration for previous investigation and adding pictures to identify concern. Also defining calibration update information.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493F
Published date: 03/12/2018
NHTSA ID Number: 10129081
Manufacturer Communication Number: PIP5493E
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017. Changes to Preliminary information include adding MY2018, advising of calibration for previous investigation and adding pictures to identify concern.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493E
Published date: 01/19/2018
NHTSA ID Number: 10123289
Manufacturer Communication Number: PIP5493D
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017. Changes to Preliminary information include adding MY2018, advising of calibration for previous investigation and adding pictures to identify concern.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493D
Published date: 10/30/2017
MC-10123289-9999.pdf 309.606KB
NHTSA ID Number: 10137699
Manufacturer Communication Number: PIP5493C
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493C
Published date: 08/3/2017
MC-10137699-9999.pdf 251.765KB
NHTSA ID Number: 10118291
Manufacturer Communication Number: PIP5493B
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493B
Published date: 06/30/2017
MC-10118291-9999.pdf 251.671KB
NHTSA ID Number: 10118251
Manufacturer Communication Number: PIP5493A
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493A
Published date: N/A
NHTSA ID Number: 10113881
Manufacturer Communication Number: PIP5493
Summary
This Preliminary information communicates diagnostic tips for misfires on active fuel management cylinders and engineering investigations into cylinder 6 misfire on XT5 and cylinder 4 misfire on LaCrosse both of which are 2017.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5493
Published date: 04/27/2017
NHTSA ID Number: 10147365
Manufacturer Communication Number: PIP5486F
Summary
This Preliminary information communicates possible concerns and a diagnostic strategy to locate and repair various noises within the engine as well as some misfire causes.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5486F
Published date: 10/9/2018
MC-10147365-9999.pdf 1708.166KB
NHTSA ID Number: 10144456
Manufacturer Communication Number: PIP5486D
Summary
This Preliminary information communicates possible concerns and a diagnostic strategy to locate and repair various noises within the engine as well as some misfire causes.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5486D
Published date: 08/14/2018
MC-10144456-9999.pdf 1375.054KB
NHTSA ID Number: 10137186
Manufacturer Communication Number: PIP5486C
Summary
This Preliminary information communicates possible concerns and a diagnostic strategy to locate and repair various noises within the engine as well as some misfire causes.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5486C
Published date: 03/13/2018
NHTSA ID Number: 10129888
Manufacturer Communication Number: PIP5486B
Summary
This Preliminary information communicates possible concerns and a diagnostic strategy to locate and repair various noises within the engine as well as some misfire causes.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5486B
Published date: 02/13/2018
NHTSA ID Number: 10126920
Manufacturer Communication Number: PIP5486A
Summary
This Preliminary information communicates possible concerns and a diagnostic strategy to locate and repair various noises within the engine as well as some misfire causes.
1 Associated Document
Manufacturer Communications
Bulletin No.: PIP5486A
Published date: 12/1/2017
- Full Synthetic Formulation: This pack of 12 bottles contains premium full synthetic motor oil designed for maximum engine protection and performance.
- Viscosity Grade: SAE 5W-30 viscosity for superior cold-start protection and enhanced fuel economy.
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- Bottle Size: Each bottle contains 1 quart (0.946 liters) of motor oil.
- Brand: Reputable ACDelco brand known for quality automotive products.
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- For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual.
- Advanced full synthetic formula
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- Viscosity: 0W40 and 5W30
- Some ACDelco GM Original Equipment parts may have formerly appeared as GM Genuine Parts (OE) or ACDelco Professional
- 5W30
- 1 Quart Bottles
- Set of 6
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