PIP5847A

Bulletin No.: PIP5847A
Published date: 08/2/2023
Preliminary Information
PIP5847A Diagnostic Tip: Abnormal Engine Ticking or Tapping
Noise From Cam Carrier Area And Possible Mis re Or Rough Run
With DTC P0300
Proactive
Models
Brand:
Model:
Model Years:
VIN:
from
to
Engine:
Transmissions:
Chevrolet
Silverado
2019 - 2023
All
All
2.7 L3B
All
GMC
Sierra
2019 - 2023
All
All
2.7 L3B
All
Involved Region or
Country:
Condition:
Cause:
North America
Abnormal engine tapping noise from Cam Carrier area and possible
misfire with DTC P0300.
Excessive movement in Exhaust Roller Follower roller due to axle pin
wear.
Correction
If you encounter a vehicle with an abnormal engine tapping noise coming from the Cam
Carrier area and possibly be accompanied by a misfire concern with one or more DTC’s,
P0300-P0304.
Use a stethoscope see if the engine noise can be isolated to the exhaust side of the Cam
Carrier. If the engine noise has been isolated to the exhaust side of the Cam Carrier, this
could be caused by a worn Exhaust Roller follower and would require the removal of the Cam
Carrier assembly for further inspection. (Please refer to published Service Information for
Cam Carrier removal)
Once the Cam Carrier has been removed inspect each of the Exhaust Follower rollers for
increased wear or up and down movement in the roller. The excessive up/down movement is
an indication of increased axle pin wear and in worst cases the rollers can come out of
position leading to a bent valve or damaged valve stem.
(Picture below showing bent valve due to worn Exhaust Roller Follower)
(Picture below shows a typical method used to check for worn roller followers)
(Picture below shows example of excessive axle pin wear)
Note: Inspect the cylinder head area for any loose roller bearings and remove before
reassembly. Each of the roller followers will have a total of 10 roller bearings.
If a worn Exhaust Roller Follower is found, replace all 8 of the Exhaust Hydraulic Lash
adjusters and Exhaust Followers. Also the Exhaust Camshaft should be inspected at this
time for damage or premature wear caused by this concern.
( Blue arrow in picture below showing Exhaust Cam lobe wear due to worn roller follower)
Note: This PI will become a bulletin as additional information becomes available.
Additional SI Keywords
knock, knocking, noise, tap, tick, ticking,
Version History
Version
Modi ed
2
04/05/2022 - Created on.
08/02/2023 Updated to include 2023 model year
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