PIP5486A

Bulletin No.: PIP5486A
Published date: 12/1/2017
Preliminary Information
PIP5486A Ticking, Tap, or Rattle Noise From Engine With Possible Misfire DTCs.
Models
Brand:
Model:
Model Years:
VIN:
from
Engine:
to
Transmissions:
Buick
LaCrosse
2017 - 2018
ALL
ALL
3.6 LGX
ALL
Cadillac
ATS
2016 - 2018
ALL
ALL
3.6 LGX
ALL
Cadillac
CT6
2016 - 2018
ALL
ALL
3.0 LGW, 3.6 LGX
ALL
Cadillac
CTS
2016 - 2018
ALL
ALL
3.6 LGX
ALL
Cadillac
XT5
2017 - 2018
ALL
ALL
3.6 LGX
ALL
Chevrolet
Camaro
2016 - 2018
ALL
ALL
3.6 LGX
ALL
Chevrolet
Colorado
2017 - 2018
ALL
ALL
3.6 LGZ
ALL
GMC
Acadia
2017 - 2018
ALL
ALL
3.6 LGX
ALL
GMC
Canyon
2017 - 2018
ALL
ALL
3.6 LGZ
ALL
Involved Region or Country North America
Additional Options (RPO)
N/A
Customers may bring their vehicle into the dealership for a rattle, tick, or knock type noise. This noise
may also be accompanied by DTC P0300, P0302 or P0305 on the Active Fuel management System (AFM)
cylinders.
Note: If there are any drivability concerns they should be addressed prior to the following
diagnostic progression including any misfire DTC.
Note: Please take a sound file or video with sound of the noise prior to dis-assembly.
Condition
This may be needed when contacting TAC or to be sent to engineering.
This 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 PI in ORDER may help pinpoint the concern.
This condition may be caused by spongy stationary hydraulic lash adjusters (SHLAs) (lifters) or a
Cause
damaged switching roller finger followers (SRFF). The condition could be all the time, only under load,
or intermittent depending on the cause.
Correction:
1) Perform injector diagnosis to ensure there are no leaking injectors causing a noise due to excessive fuel in 1 cylinder
a) Perform GDS2 or AFIT test on injectors to isolate a leaking injector.
b) Replace any out of specification injectors
c) Reevaluate the noise.
2) Perform cylinder cancellation for each cylinder may help pinpoint source of rattle noise.
3) Remove the intake manifold and visually inspect for excessive carbon on the intake valve stems and top of the valve causing noise.
a) If carbon is present then follow the latest version of PIP5029 to clean the valves or replace heads as needed.
b) Reevaluate the noise concern.
4) Remove the cam cover of the affected bank (both if needed) to inspect for soft or (SHLAs) on all cylinders.
a) Push down on the rocker end at the SHLA noted below to test for soft or spongy.
b) If soft or spongy SHLAs are found on either the intake or exhaust side of any cylinder it will be necessary to replace the affected
SHLAs and retest.
NOTE: If all shla's (lifters) are hard proceed to step 5
a) 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 noted below.
b) If debris is found, inspect the camshaft caps for wear or discoloration due to lack of oil.
c) If wear or discoloration is found then replace the cylinder head assembly with camshafts.
d) If there is no wear or discoloration, clean the oil passages and replace the head gasket.
e) Change the oil and filter
f) Reevaluate the noise concern.
5) Without starting 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 (SRFF) for any damage.
6) Inspect the SRFF' and rocker assemblies for any damage or dislodge.
Camshaft carrier assembly removal will be necessary to fully inspect the rockers and SRFF's.
Below are pictures of possible SRFF failures.
If any one of the SRFF’s are damaged it will be necessary to replace all four on the affected cylinder.
For the above conditions engine replacement is not necessary.
Please perform the repairs for these conditions.
7) If noise condition is still present proceed to step 8.
8) Raise the vehicle while running or with an assistant inside.
a) With chassis ears or a stethoscope, listen to the right and left side of the engine
b) 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. We have seen both.
c) There should be no metal through the oil for this condition.
d) If this is found a piston and rod assembly will repair this noise.
Once all of the above inspections and / or diagnostics are completed, If nothing is found to be the cause for the noise, engine
replacement MAY be necessary.
Warranty Information
For Vehicles Repaired Under Warranty Use Appropriate Labor Operation For Process Performed.
Version History
Version
2
Modified
12/01/2017 - Updated to add Model year
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