2. Remove the camshaft cover (w/solenoids installed
in cover if LH bank, remove solenoids from cover
first if RH bank).
3. With aid of helper, rotate the engine from below by
the crankshaft damper bolt until the Intake Cyl #1
(LH) or Intake Cyl #2 (RH) cam lobes are pointed
straight up to the top of the cap (on base circle).
– This is the first cam cap that will be adjusted per
the steps 4-8 below.
– Note that the larger front camshaft caps behind
the actuators will NOT be adjusted with this
procedure.

Page 12

August, 2023

Important: Always remember to work from front to rear
when performing the re-alignment procedure.
For the Bank 1 adjustment procedure, the cam lobes
can be monitored through the wheel well opening to
properly position.
4. Loosen the cam cap bolts on the cap to be
adjusted 1 full turn.
– Do not remove or physically try to shift, wiggle, or
adjust the cap seating.
5. Tighten the inner camshaft cap bolt first to 15
N.m (11 lb ft).
Note: The inner camshaft cap bolt is the one closest to
the spark plug tube.
6. Tighten the outer camshaft cap bolt first to 15
N.m (11 lb ft).
Note: The outer camshaft cap bolt is the one farthest
away from the spark plug tube.
7. Make a second pass on both camshaft cap bolts to
confirm each is torqued to 15 N.m (11 lb ft).
8. Place a black sharpie mark on the cam cap
adjusted to note that it has been completed.
Important: During each camshaft cap adjustment
step, ensure the camshaft lobes are at base circle.
9. Rotate the engine until the next valve position
working from front to rear on the intake camshaft.
Ensure the lobes are pointing straight up to the top
of the cap. Repeat steps 4-8 on that position with
the lobes up.
10. Repeat the steps 4-8 above on the exhaust
camshaft caps on the same engine bank (LH, RH)
depending on the side on which you are
working on.
Important: Always remember to work from front to rear
when performing the re-alignment procedure.
11. Reinstall the cam cover and solenoids (if removed)
and reconnect electrical.
12. Once the exhaust and intake camshaft cap bolts
have been re-torqued, the engine can be
reassembled.
Important: If the work was done with the engine still in
vehicle (LH bank) and the cam phasing solenoids were
left installed in the cam cover, it is critical to make sure
that the solenoid plungers are fully recessed before
lowering the cover onto the engine. The plungers can
loosely move inward and outward. Tip the cam cover
front (solenoids) end down to make sure plungers are
in/down. Carefully move cover with the front (solenoid)
end tilted slightly down while positioning onto the
engine to prevent plungers from extending. If the
solenoid plungers are extended out, they will catch on
the phaser OCV center bolt plunger and be bent –
phasing will not work and both the solenoid and OCV
will need to be replaced.

Bulletin No.: 23-NA-115

Bulletin No.: 23-NA-115

August, 2023

Page 13

Parts Information
Note: Only select the parts that coincide with the repair
performed. Replace the part with the P/N outlined in the
Electronic Parts Catalog (EPC) in accordance with the
vehicle VIN.
Causal Part

Description

Part Number

Qty

Bank

N/A

SEAL, OIL TRFER
TUBE O-RING

12697070

1

Right Bank

N/A

SEAL, OIL TRFER
TUBE O-RING

12697071

1

Right Bank

N/A

GASKET, EXH MANIF

12673594

1

Both Banks

N/A

GASKET, INT MANIF

12668302

8

Both Banks

N/A

BOLT, R/AXL SHF

11601876

12

Right Bank

N/A

FILTER KIT, OIL

12730579

1

Both Banks

N/A

OIL, ENG (5W-50)
SUPERCAR MOBIL 1

19433208 (in Canada,
19434897)

8

Both Banks

N/A

SEALANT

19369831 (U.S)
19369832 (Canada)

1

Both Banks

N/A

SEAL, CM/SHF
HSG CVR

12672530 Right

1

Right Bank

N/A

SEAL, CM/SHF
HSG CVR

12672531 Left

1

Left Bank

N/A

SEAL, SPLG SHLD

12672529

4

Both Banks

N/A

GASKET,
CTLTC CONV

10354707

1

Both Banks

N/A

GASKET,
CTLTC CONV

12672379

1

Both Banks

N/A

GASKET, PCV
OIL SEP

12695546

1

Left Bank

N/A

SEAL, SPLG SHLD

12672529

1

Left Bank

N/A

BOLT, EXH MANIF

11546600

5

Both Banks

Page 14

August, 2023

Bulletin No.: 23-NA-115

Warranty Information
Note: Only select the Labor Operation that coincides
with the repair performed.
For vehicles repaired under the Powertrain coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor
Operation

Description

Labor Time

4089038*

Record and Review
Sound File

0.5 hr

4089048*

Camshaft Cap Realignment
Bank 1 (Driver’s Side)
Coupe

9.9 hrs

4089058*

Camshaft Cap Realignment
Bank 2 (Passenger Side)
Coupe

17.3 hrs

4089068*

Camshaft Cap Realignment
Bank 1 (Driver’s Side)
Convertible

6.6 hrs

4089078*

Camshaft Cap Realignment
Bank 2 (Passenger Side)
Convertible

16.6 hrs

*This is a unique Labor Operation for bulletin use only.

Version

2

Modified

Released June 28, 2023
Revised August 16, 2023 – Added an Important statement at beginning of Camshaft Cap
Re-Alignment Procedure and after Step 8 and clarified step 9.

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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